blob: a299b012393c600068fec2bc87be290a4a74192a [file] [log] [blame]
/* vi: set sw=4 ts=4: */
/*
* sh.c -- a prototype Bourne shell grammar parser
* Intended to follow the original Thompson and Ritchie
* "small and simple is beautiful" philosophy, which
* incidentally is a good match to today's BusyBox.
*
* Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
*
* Credits:
* The parser routines proper are all original material, first
* written Dec 2000 and Jan 2001 by Larry Doolittle. The
* execution engine, the builtins, and much of the underlying
* support has been adapted from busybox-0.49pre's lash, which is
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* written by Erik Andersen <andersen@codepoet.org>. That, in turn,
* is based in part on ladsh.c, by Michael K. Johnson and Erik W.
* Troan, which they placed in the public domain. I don't know
* how much of the Johnson/Troan code has survived the repeated
* rewrites.
*
* Other credits:
* b_addchr() derived from similar w_addchar function in glibc-2.2
* setup_redirect(), redirect_opt_num(), and big chunks of main()
* and many builtins derived from contributions by Erik Andersen
* miscellaneous bugfixes from Matt Kraai
*
* There are two big (and related) architecture differences between
* this parser and the lash parser. One is that this version is
* actually designed from the ground up to understand nearly all
* of the Bourne grammar. The second, consequential change is that
* the parser and input reader have been turned inside out. Now,
* the parser is in control, and asks for input as needed. The old
* way had the input reader in control, and it asked for parsing to
* take place as needed. The new way makes it much easier to properly
* handle the recursion implicit in the various substitutions, especially
* across continuation lines.
*
* Bash grammar not implemented: (how many of these were in original sh?)
* $@ (those sure look like weird quoting rules)
* $_
* ! negation operator for pipes
* &> and >& redirection of stdout+stderr
* Brace Expansion
* Tilde Expansion
* fancy forms of Parameter Expansion
* aliases
* Arithmetic Expansion
* <(list) and >(list) Process Substitution
* reserved words: case, esac, select, function
* Here Documents ( << word )
* Functions
* Major bugs:
* job handling woefully incomplete and buggy (improved --vda)
* reserved word execution woefully incomplete and buggy
* to-do:
* port selected bugfixes from post-0.49 busybox lash - done?
* finish implementing reserved words: for, while, until, do, done
* change { and } from special chars to reserved words
* builtins: break, continue, eval, return, set, trap, ulimit
* test magic exec
* handle children going into background
* clean up recognition of null pipes
* check setting of global_argc and global_argv
* control-C handling, probably with longjmp
* follow IFS rules more precisely, including update semantics
* figure out what to do with backslash-newline
* explain why we use signal instead of sigaction
* propagate syntax errors, die on resource errors?
* continuation lines, both explicit and implicit - done?
* memory leak finding and plugging - done?
* more testing, especially quoting rules and redirection
* document how quoting rules not precisely followed for variable assignments
* maybe change map[] to use 2-bit entries
* (eventually) remove all the printf's
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include "busybox.h"
#include <glob.h> /* glob, of course */
#include <getopt.h> /* should be pretty obvious */
/* #include <dmalloc.h> */
/* If you comment out one of these below, it will be #defined later
* to perform debug printfs to stderr: */
#define debug_printf(...) do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_jobs(...) do {} while (0)
#define debug_printf_exec(...) do {} while (0)
#define debug_printf_parse(...) do {} while (0)
#define debug_print_tree(a, b) do {} while (0)
#ifndef debug_printf
#define debug_printf(...) fprintf(stderr, __VA_ARGS__)
/* broken, of course, but OK for testing */
static const char *indenter(int i)
{
static const char blanks[] = " ";
return &blanks[sizeof(blanks) - i - 1];
}
#endif
#define final_printf debug_printf
#ifndef debug_printf_jobs
#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_SHELL_JOBS 1
#endif
#ifndef debug_printf_exec
#define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_parse
#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
#endif
#if !ENABLE_HUSH_INTERACTIVE
#undef ENABLE_FEATURE_EDITING
#define ENABLE_FEATURE_EDITING 0
#undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif
#define SPECIAL_VAR_SYMBOL 3
#define FLAG_EXIT_FROM_LOOP 1
#define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
#define FLAG_REPARSING (1 << 2) /* >= 2nd pass */
typedef enum {
REDIRECT_INPUT = 1,
REDIRECT_OVERWRITE = 2,
REDIRECT_APPEND = 3,
REDIRECT_HEREIS = 4,
REDIRECT_IO = 5
} redir_type;
/* The descrip member of this structure is only used to make debugging
* output pretty */
static const struct {
int mode;
signed char default_fd;
char descrip[3];
} redir_table[] = {
{ 0, 0, "()" },
{ O_RDONLY, 0, "<" },
{ O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
{ O_RDONLY, -1, "<<" },
{ O_RDWR, 1, "<>" }
};
typedef enum {
PIPE_SEQ = 1,
PIPE_AND = 2,
PIPE_OR = 3,
PIPE_BG = 4,
} pipe_style;
/* might eventually control execution */
typedef enum {
RES_NONE = 0,
RES_IF = 1,
RES_THEN = 2,
RES_ELIF = 3,
RES_ELSE = 4,
RES_FI = 5,
RES_FOR = 6,
RES_WHILE = 7,
RES_UNTIL = 8,
RES_DO = 9,
RES_DONE = 10,
RES_XXXX = 11,
RES_IN = 12,
RES_SNTX = 13
} reserved_style;
enum {
FLAG_END = (1 << RES_NONE ),
FLAG_IF = (1 << RES_IF ),
FLAG_THEN = (1 << RES_THEN ),
FLAG_ELIF = (1 << RES_ELIF ),
FLAG_ELSE = (1 << RES_ELSE ),
FLAG_FI = (1 << RES_FI ),
FLAG_FOR = (1 << RES_FOR ),
FLAG_WHILE = (1 << RES_WHILE),
FLAG_UNTIL = (1 << RES_UNTIL),
FLAG_DO = (1 << RES_DO ),
FLAG_DONE = (1 << RES_DONE ),
FLAG_IN = (1 << RES_IN ),
FLAG_START = (1 << RES_XXXX ),
};
/* This holds pointers to the various results of parsing */
struct p_context {
struct child_prog *child;
struct pipe *list_head;
struct pipe *pipe;
struct redir_struct *pending_redirect;
reserved_style res_w;
int old_flag; /* for figuring out valid reserved words */
struct p_context *stack;
int parse_type; /* define type of parser : ";$" common or special symbol */
/* How about quoting status? */
};
struct redir_struct {
struct redir_struct *next; /* pointer to the next redirect in the list */
redir_type type; /* type of redirection */
int fd; /* file descriptor being redirected */
int dup; /* -1, or file descriptor being duplicated */
glob_t word; /* *word.gl_pathv is the filename */
};
struct child_prog {
pid_t pid; /* 0 if exited */
char **argv; /* program name and arguments */
struct pipe *group; /* if non-NULL, first in group or subshell */
int subshell; /* flag, non-zero if group must be forked */
struct redir_struct *redirects; /* I/O redirections */
glob_t glob_result; /* result of parameter globbing */
int is_stopped; /* is the program currently running? */
struct pipe *family; /* pointer back to the child's parent pipe */
int sp; /* number of SPECIAL_VAR_SYMBOL */
int type;
};
struct pipe {
struct pipe *next;
int num_progs; /* total number of programs in job */
int running_progs; /* number of programs running (not exited) */
char *cmdbuf; /* buffer various argv's point into */
#if ENABLE_HUSH_JOB
int jobid; /* job number */
char *cmdtext; /* name of job */
pid_t pgrp; /* process group ID for the job */
#endif
struct child_prog *progs; /* array of commands in pipe */
int stopped_progs; /* number of programs alive, but stopped */
int job_context; /* bitmask defining current context */
pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
reserved_style r_mode; /* supports if, for, while, until */
};
struct close_me {
struct close_me *next;
int fd;
};
struct variables {
struct variables *next;
const char *name;
const char *value;
int flg_export;
int flg_read_only;
};
/* globals, connect us to the outside world
* the first three support $?, $#, and $1 */
static char **global_argv;
static int global_argc;
static int last_return_code;
extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
/* "globals" within this file */
enum {
MAP_ORDINARY = 0,
MAP_FLOWTROUGH_IF_QUOTED = 1,
MAP_IFS_IF_UNQUOTED = 2, /* flow through if quoted too */
MAP_NEVER_FLOWTROUGH = 3,
};
static unsigned char map[256];
static const char *ifs;
static int fake_mode;
static struct close_me *close_me_head;
static const char *cwd;
static unsigned last_bg_pid;
#if !ENABLE_HUSH_INTERACTIVE
enum { interactive_fd = 0 };
#else
/* 'interactive_fd' is a fd# open to ctty, if we have one
* _AND_ if we decided to mess with job control */
static int interactive_fd;
#if ENABLE_HUSH_JOB
static pid_t saved_task_pgrp;
static pid_t saved_tty_pgrp;
static int last_jobid;
static struct pipe *job_list;
#endif
static const char *PS1;
static const char *PS2;
#endif
#define HUSH_VER_STR "0.02"
static struct variables shell_ver = { NULL, "HUSH_VERSION", HUSH_VER_STR, 1, 1 };
static struct variables *top_vars = &shell_ver;
#define B_CHUNK 100
#define B_NOSPAC 1
typedef struct {
char *data;
int length;
int maxlen;
int quote;
int nonnull;
} o_string;
#define NULL_O_STRING {NULL,0,0,0,0}
/* used for initialization:
o_string foo = NULL_O_STRING; */
/* I can almost use ordinary FILE *. Is open_memstream() universally
* available? Where is it documented? */
struct in_str {
const char *p;
char peek_buf[2];
#if ENABLE_HUSH_INTERACTIVE
int __promptme;
int promptmode;
#endif
FILE *file;
int (*get) (struct in_str *);
int (*peek) (struct in_str *);
};
#define b_getch(input) ((input)->get(input))
#define b_peek(input) ((input)->peek(input))
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
struct built_in_command {
const char *cmd; /* name */
const char *descr; /* description */
int (*function) (char **argv); /* function ptr */
};
static void __syntax(int line)
{
bb_error_msg("syntax error hush.c:%d", line);
}
#define syntax() __syntax(__LINE__)
/* Index of subroutines: */
/* function prototypes for builtins */
static int builtin_cd(char **argv);
static int builtin_eval(char **argv);
static int builtin_exec(char **argv);
static int builtin_exit(char **argv);
static int builtin_export(char **argv);
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv);
static int builtin_jobs(char **argv);
#endif
static int builtin_help(char **argv);
static int builtin_pwd(char **argv);
static int builtin_read(char **argv);
static int builtin_set(char **argv);
static int builtin_shift(char **argv);
static int builtin_source(char **argv);
static int builtin_umask(char **argv);
static int builtin_unset(char **argv);
static int builtin_not_written(char **argv);
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
static void b_reset(o_string *o);
static int b_addqchr(o_string *o, int ch, int quote);
static int b_adduint(o_string *o, unsigned i);
/* in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
static int file_get(struct in_str *i);
static int file_peek(struct in_str *i);
static void setup_file_in_str(struct in_str *i, FILE *f);
static void setup_string_in_str(struct in_str *i, const char *s);
/* close_me manipulations: */
static void mark_open(int fd);
static void mark_closed(int fd);
static void close_all(void);
/* "run" the final data structures: */
static int free_pipe_list(struct pipe *head, int indent);
static int free_pipe(struct pipe *pi, int indent);
/* really run the final data structures: */
static int setup_redirects(struct child_prog *prog, int squirrel[]);
static int run_list_real(struct pipe *pi);
static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
static int run_pipe_real(struct pipe *pi);
/* extended glob support: */
static int globhack(const char *src, int flags, glob_t *pglob);
static int glob_needed(const char *s);
static int xglob(o_string *dest, int flags, glob_t *pglob);
/* variable assignment: */
static int is_assignment(const char *s);
/* data structure manipulation: */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
static void initialize_context(struct p_context *ctx);
static int done_word(o_string *dest, struct p_context *ctx);
static int done_command(struct p_context *ctx);
static int done_pipe(struct p_context *ctx, pipe_style type);
/* primary string parsing: */
static int redirect_dup_num(struct in_str *input);
static int redirect_opt_num(o_string *o);
static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end);
static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
static const char *lookup_param(const char *src);
static char *make_string(char **inp);
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
/* setup: */
static int parse_stream_outer(struct in_str *inp, int parse_flag);
static int parse_string_outer(const char *s, int parse_flag);
static int parse_file_outer(FILE *f);
/* job management: */
static int checkjobs(struct pipe* fg_pipe);
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
static void insert_bg_job(struct pipe *pi);
static void remove_bg_job(struct pipe *pi);
static void delete_finished_bg_job(struct pipe *pi);
#else
int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
#endif
/* local variable support */
static char **make_list_in(char **inp, char *name);
static char *insert_var_value(char *inp);
static const char *get_local_var(const char *var);
static int set_local_var(const char *s, int flg_export);
static void unset_local_var(const char *name);
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
* When used in non-forking context, they can change global variables
* in the parent shell process. If forked, of course they cannot.
* For example, 'unset foo | whatever' will parse and run, but foo will
* still be set at the end. */
static const struct built_in_command bltins[] = {
#if ENABLE_HUSH_JOB
{ "bg", "Resume a job in the background", builtin_fg_bg },
#endif
{ "break", "Exit for, while or until loop", builtin_not_written },
{ "cd", "Change working directory", builtin_cd },
{ "continue", "Continue for, while or until loop", builtin_not_written },
{ "eval", "Construct and run shell command", builtin_eval },
{ "exec", "Exec command, replacing this shell with the exec'd process",
builtin_exec },
{ "exit", "Exit from shell()", builtin_exit },
{ "export", "Set environment variable", builtin_export },
#if ENABLE_HUSH_JOB
{ "fg", "Bring job into the foreground", builtin_fg_bg },
{ "jobs", "Lists the active jobs", builtin_jobs },
#endif
{ "pwd", "Print current directory", builtin_pwd },
{ "read", "Input environment variable", builtin_read },
{ "return", "Return from a function", builtin_not_written },
{ "set", "Set/unset shell local variables", builtin_set },
{ "shift", "Shift positional parameters", builtin_shift },
{ "trap", "Trap signals", builtin_not_written },
{ "ulimit","Controls resource limits", builtin_not_written },
{ "umask","Sets file creation mask", builtin_umask },
{ "unset", "Unset environment variable", builtin_unset },
{ ".", "Source-in and run commands in a file", builtin_source },
{ "help", "List shell built-in commands", builtin_help },
{ NULL, NULL, NULL }
};
#if ENABLE_HUSH_JOB
/* move to libbb? */
static void signal_SA_RESTART(int sig, void (*handler)(int))
{
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = SA_RESTART;
sigemptyset(&sa.sa_mask);
sigaction(sig, &sa, NULL);
}
/* Signals are grouped, we handle them in batches */
static void set_fatal_sighandler(void (*handler)(int))
{
signal(SIGILL , handler);
signal(SIGTRAP, handler);
signal(SIGABRT, handler);
signal(SIGFPE , handler);
signal(SIGBUS , handler);
signal(SIGSEGV, handler);
/* bash 3.2 seems to handle these just like 'fatal' ones */
signal(SIGHUP , handler);
signal(SIGPIPE, handler);
signal(SIGALRM, handler);
}
static void set_jobctrl_sighandler(void (*handler)(int))
{
signal(SIGTSTP, handler);
signal(SIGTTIN, handler);
signal(SIGTTOU, handler);
}
static void set_misc_sighandler(void (*handler)(int))
{
signal(SIGINT , handler);
signal(SIGQUIT, handler);
signal(SIGTERM, handler);
}
/* SIGCHLD is special and handled separately */
static void set_every_sighandler(void (*handler)(int))
{
set_fatal_sighandler(handler);
set_jobctrl_sighandler(handler);
set_misc_sighandler(handler);
signal(SIGCHLD, handler);
}
static struct pipe *toplevel_list;
static sigjmp_buf toplevel_jb;
smallint ctrl_z_flag;
#if ENABLE_FEATURE_SH_STANDALONE
struct nofork_save_area nofork_save;
#endif
static void handler_ctrl_c(int sig)
{
debug_printf_jobs("got sig %d\n", sig);
// as usual we can have all kinds of nasty problems with leaked malloc data here
siglongjmp(toplevel_jb, 1);
}
static void handler_ctrl_z(int sig)
{
pid_t pid;
debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
pid = fork();
if (pid < 0) /* can't fork. Pretend there were no ctrl-Z */
return;
ctrl_z_flag = 1;
//vda: wrong!!
// toplevel_list->running_progs = 1;
// toplevel_list->stopped_progs = 0;
//
if (!pid) { /* child */
setpgrp();
debug_printf_jobs("set pgrp for child %d ok\n", getpid());
set_every_sighandler(SIG_DFL);
raise(SIGTSTP); /* resend TSTP so that child will be stopped */
debug_printf_jobs("returning in child\n");
/* return to nofork, it will eventually exit now,
* not return back to shell */
return;
}
/* parent */
/* finish filling up pipe info */
toplevel_list->pgrp = pid; /* child is in its own pgrp */
toplevel_list->progs[0].pid = pid;
//vda: wrong!!
// toplevel_list->running_progs = 1;
// toplevel_list->stopped_progs = 0;
/* parent needs to longjmp out of running nofork.
* we will "return" exitcode 0, with child put in background */
// as usual we can have all kinds of nasty problems with leaked malloc data here
debug_printf_jobs("siglongjmp in parent\n");
siglongjmp(toplevel_jb, 1);
}
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will faithfully resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
* We also call it if xfunc is exiting. */
static void sigexit(int sig) ATTRIBUTE_NORETURN;
static void sigexit(int sig)
{
sigset_t block_all;
/* Disable all signals: job control, SIGPIPE, etc. */
sigfillset(&block_all);
sigprocmask(SIG_SETMASK, &block_all, NULL);
if (interactive_fd)
tcsetpgrp(interactive_fd, saved_tty_pgrp);
/* Not a signal, just exit */
if (sig <= 0)
_exit(- sig);
/* Enable only this sig and kill ourself with it */
signal(sig, SIG_DFL);
sigdelset(&block_all, sig);
sigprocmask(SIG_SETMASK, &block_all, NULL);
raise(sig);
_exit(1); /* Should not reach it */
}
/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
static void hush_exit(int exitcode)
{
fflush(NULL); /* flush all streams */
sigexit(- (exitcode & 0xff));
}
#else /* !JOB */
#define set_fatal_sighandler(handler) ((void)0)
#define set_jobctrl_sighandler(handler) ((void)0)
#define set_misc_sighandler(handler) ((void)0)
#define hush_exit(e) exit(e)
#endif /* JOB */
static const char *set_cwd(void)
{
if (cwd == bb_msg_unknown)
cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
cwd = xrealloc_getcwd_or_warn((char *)cwd);
if (!cwd)
cwd = bb_msg_unknown;
return cwd;
}
/* built-in 'eval' handler */
static int builtin_eval(char **argv)
{
char *str = NULL;
int rcode = EXIT_SUCCESS;
if (argv[1]) {
str = make_string(argv + 1);
parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
FLAG_PARSE_SEMICOLON);
free(str);
rcode = last_return_code;
}
return rcode;
}
/* built-in 'cd <path>' handler */
static int builtin_cd(char **argv)
{
char *newdir;
if (argv[1] == NULL)
newdir = getenv("HOME");
else
newdir = argv[1];
if (chdir(newdir)) {
printf("cd: %s: %s\n", newdir, strerror(errno));
return EXIT_FAILURE;
}
set_cwd();
return EXIT_SUCCESS;
}
/* built-in 'exec' handler */
static int builtin_exec(char **argv)
{
if (argv[1] == NULL)
return EXIT_SUCCESS; /* Really? */
pseudo_exec_argv(argv + 1);
/* never returns */
}
/* built-in 'exit' handler */
static int builtin_exit(char **argv)
{
// TODO: bash does it ONLY on top-level sh exit (+interacive only?)
//puts("exit"); /* bash does it */
// TODO: warn if we have background jobs: "There are stopped jobs"
// On second consecutive 'exit', exit anyway.
if (argv[1] == NULL)
hush_exit(last_return_code);
/* mimic bash: exit 123abc == exit 255 + error msg */
xfunc_error_retval = 255;
/* bash: exit -2 == exit 254, no error msg */
hush_exit(xatoi(argv[1]) & 0xff);
}
/* built-in 'export VAR=value' handler */
static int builtin_export(char **argv)
{
int res = 0;
char *name = argv[1];
if (name == NULL) {
// TODO:
// ash emits: export VAR='VAL'
// bash: declare -x VAR="VAL"
// (both also escape as needed (quotes, $, etc))
char **e = environ;
if (e)
while (*e)
puts(*e++);
return EXIT_SUCCESS;
}
name = strdup(name);
if (name) {
const char *value = strchr(name, '=');
if (!value) {
char *tmp;
/* They are exporting something without an =VALUE */
value = get_local_var(name);
if (value) {
size_t ln = strlen(name);
tmp = realloc(name, ln+strlen(value)+2);
if (tmp == NULL)
res = -1;
else {
sprintf(tmp+ln, "=%s", value);
name = tmp;
}
} else {
/* bash does not return an error when trying to export
* an undefined variable. Do likewise. */
res = 1;
}
}
}
if (res < 0)
bb_perror_msg("export");
else if (res == 0)
res = set_local_var(name, 1);
else
res = 0;
free(name);
return res;
}
#if ENABLE_HUSH_JOB
/* built-in 'fg' and 'bg' handler */
static int builtin_fg_bg(char **argv)
{
int i, jobnum;
struct pipe *pi;
if (!interactive_fd)
return EXIT_FAILURE;
/* If they gave us no args, assume they want the last backgrounded task */
if (!argv[1]) {
for (pi = job_list; pi; pi = pi->next) {
if (pi->jobid == last_jobid) {
goto found;
}
}
bb_error_msg("%s: no current job", argv[0]);
return EXIT_FAILURE;
}
if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
return EXIT_FAILURE;
}
for (pi = job_list; pi; pi = pi->next) {
if (pi->jobid == jobnum) {
goto found;
}
}
bb_error_msg("%s: %d: no such job", argv[0], jobnum);
return EXIT_FAILURE;
found:
// TODO: bash prints a string representation
// of job being foregrounded (like "sleep 1 | cat")
if (*argv[0] == 'f') {
/* Put the job into the foreground. */
tcsetpgrp(interactive_fd, pi->pgrp);
}
/* Restart the processes in the job */
debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
for (i = 0; i < pi->num_progs; i++) {
debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
pi->progs[i].is_stopped = 0;
}
pi->stopped_progs = 0;
i = kill(- pi->pgrp, SIGCONT);
if (i < 0) {
if (errno == ESRCH) {
delete_finished_bg_job(pi);
return EXIT_SUCCESS;
} else {
bb_perror_msg("kill (SIGCONT)");
}
}
if (*argv[0] == 'f') {
remove_bg_job(pi);
return checkjobs_and_fg_shell(pi);
}
return EXIT_SUCCESS;
}
#endif
/* built-in 'help' handler */
static int builtin_help(char **argv ATTRIBUTE_UNUSED)
{
const struct built_in_command *x;
printf("\nBuilt-in commands:\n");
printf("-------------------\n");
for (x = bltins; x->cmd; x++) {
if (x->descr == NULL)
continue;
printf("%s\t%s\n", x->cmd, x->descr);
}
printf("\n\n");
return EXIT_SUCCESS;
}
#if ENABLE_HUSH_JOB
/* built-in 'jobs' handler */
static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
{
struct pipe *job;
const char *status_string;
for (job = job_list; job; job = job->next) {
if (job->running_progs == job->stopped_progs)
status_string = "Stopped";
else
status_string = "Running";
printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
}
return EXIT_SUCCESS;
}
#endif
/* built-in 'pwd' handler */
static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
{
puts(set_cwd());
return EXIT_SUCCESS;
}
/* built-in 'read VAR' handler */
static int builtin_read(char **argv)
{
int res;
if (argv[1]) {
char string[BUFSIZ];
char *var = NULL;
string[0] = '\0'; /* In case stdin has only EOF */
/* read string */
fgets(string, sizeof(string), stdin);
chomp(string);
var = malloc(strlen(argv[1]) + strlen(string) + 2);
if (var) {
sprintf(var, "%s=%s", argv[1], string);
res = set_local_var(var, 0);
} else
res = -1;
if (res)
bb_perror_msg("read");
free(var); /* So not move up to avoid breaking errno */
return res;
}
do res = getchar(); while (res != '\n' && res != EOF);
return 0;
}
/* built-in 'set VAR=value' handler */
static int builtin_set(char **argv)
{
char *temp = argv[1];
struct variables *e;
if (temp == NULL)
for (e = top_vars; e; e = e->next)
printf("%s=%s\n", e->name, e->value);
else
set_local_var(temp, 0);
return EXIT_SUCCESS;
}
/* Built-in 'shift' handler */
static int builtin_shift(char **argv)
{
int n = 1;
if (argv[1]) {
n = atoi(argv[1]);
}
if (n >= 0 && n < global_argc) {
/* XXX This probably breaks $0 */
global_argc -= n;
global_argv += n;
return EXIT_SUCCESS;
}
return EXIT_FAILURE;
}
/* Built-in '.' handler (read-in and execute commands from file) */
static int builtin_source(char **argv)
{
FILE *input;
int status;
if (argv[1] == NULL)
return EXIT_FAILURE;
/* XXX search through $PATH is missing */
input = fopen(argv[1], "r");
if (!input) {
bb_error_msg("cannot open '%s'", argv[1]);
return EXIT_FAILURE;
}
/* Now run the file */
/* XXX argv and argc are broken; need to save old global_argv
* (pointer only is OK!) on this stack frame,
* set global_argv=argv+1, recurse, and restore. */
mark_open(fileno(input));
status = parse_file_outer(input);
mark_closed(fileno(input));
fclose(input);
return status;
}
static int builtin_umask(char **argv)
{
mode_t new_umask;
const char *arg = argv[1];
char *end;
if (arg) {
new_umask = strtoul(arg, &end, 8);
if (*end != '\0' || end == arg) {
return EXIT_FAILURE;
}
} else {
new_umask = umask(0);
printf("%.3o\n", (unsigned) new_umask);
}
umask(new_umask);
return EXIT_SUCCESS;
}
/* built-in 'unset VAR' handler */
static int builtin_unset(char **argv)
{
/* bash returned already true */
unset_local_var(argv[1]);
return EXIT_SUCCESS;
}
static int builtin_not_written(char **argv)
{
printf("builtin_%s not written\n", argv[0]);
return EXIT_FAILURE;
}
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
* in here, such as setting a maximum string length */
if (o->length + len > o->maxlen) {
char *old_data = o->data;
/* assert(data == NULL || o->maxlen != 0); */
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = realloc(o->data, 1 + o->maxlen);
if (o->data == NULL) {
free(old_data);
}
}
return o->data == NULL;
}
static int b_addchr(o_string *o, int ch)
{
debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
if (b_check_space(o, 1))
return B_NOSPAC;
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
return 0;
}
static void b_reset(o_string *o)
{
o->length = 0;
o->nonnull = 0;
if (o->data != NULL)
*o->data = '\0';
}
static void b_free(o_string *o)
{
b_reset(o);
free(o->data);
o->data = NULL;
o->maxlen = 0;
}
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static int b_addqchr(o_string *o, int ch, int quote)
{
if (quote && strchr("*?[\\", ch)) {
int rc;
rc = b_addchr(o, '\\');
if (rc)
return rc;
}
return b_addchr(o, ch);
}
static int b_adduint(o_string *o, unsigned i)
{
int r;
char buf[sizeof(unsigned)*3 + 1];
char *p = buf;
*(utoa_to_buf(i, buf, sizeof(buf))) = '\0';
/* no escape checking necessary */
do r = b_addchr(o, *p++); while (r == 0 && *p);
return r;
}
static int static_get(struct in_str *i)
{
int ch = *i->p++;
if (ch == '\0') return EOF;
return ch;
}
static int static_peek(struct in_str *i)
{
return *i->p;
}
#if ENABLE_HUSH_INTERACTIVE
#if ENABLE_FEATURE_EDITING
static void cmdedit_set_initial_prompt(void)
{
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
PS1 = NULL;
#else
PS1 = getenv("PS1");
if (PS1 == NULL)
PS1 = "\\w \\$ ";
#endif
}
#endif
static const char* setup_prompt_string(int promptmode)
{
const char *prompt_str;
debug_printf("setup_prompt_string %d ", promptmode);
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
/* Set up the prompt */
if (promptmode == 1) {
char *ns;
free((char*)PS1);
ns = xmalloc(strlen(cwd)+4);
sprintf(ns, "%s %s", cwd, (geteuid() != 0) ? "$ " : "# ");
prompt_str = ns;
PS1 = ns;
} else {
prompt_str = PS2;
}
#else
prompt_str = (promptmode == 1) ? PS1 : PS2;
#endif
debug_printf("result %s\n", prompt_str);
return prompt_str;
}
#endif /* ENABLE_HUSH_INTERACTIVE */
#if ENABLE_FEATURE_EDITING
static line_input_t *line_input_state;
#endif
#if ENABLE_HUSH_INTERACTIVE
static int get_user_input(struct in_str *i)
{
static char the_command[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
int r;
const char *prompt_str;
prompt_str = setup_prompt_string(i->promptmode);
#if ENABLE_FEATURE_EDITING
/*
** enable command line editing only while a command line
** is actually being read; otherwise, we'll end up bequeathing
** atexit() handlers and other unwanted stuff to our
** child processes (rob@sysgo.de)
*/
r = read_line_input(prompt_str, the_command, BUFSIZ, line_input_state);
#else
fputs(prompt_str, stdout);
fflush(stdout);
the_command[0] = r = fgetc(i->file);
the_command[1] = '\0';
#endif
fflush(stdout);
i->p = the_command;
return r; /* < 0 == EOF. Not meaningful otherwise */
}
#endif
/* This is the magic location that prints prompts
* and gets data back from the user */
static int file_get(struct in_str *i)
{
int ch;
ch = 0;
/* If there is data waiting, eat it up */
if (i->p && *i->p) {
ch = *i->p++;
} else {
/* need to double check i->file because we might be doing something
* more complicated by now, like sourcing or substituting. */
#if ENABLE_HUSH_INTERACTIVE
if (interactive_fd && i->__promptme && i->file == stdin) {
while (!i->p || !(interactive_fd && i->p[0])) {
if (get_user_input(i) < 0)
return EOF;
}
i->promptmode = 2;
i->__promptme = 0;
if (i->p && *i->p) {
ch = *i->p++;
}
} else
#endif
{
ch = fgetc(i->file);
}
debug_printf("b_getch: got a %d\n", ch);
}
#if ENABLE_HUSH_INTERACTIVE
if (ch == '\n')
i->__promptme = 1;
#endif
return ch;
}
/* All the callers guarantee this routine will never be
* used right after a newline, so prompting is not needed.
*/
static int file_peek(struct in_str *i)
{
if (i->p && *i->p) {
return *i->p;
}
i->peek_buf[0] = fgetc(i->file);
i->peek_buf[1] = '\0';
i->p = i->peek_buf;
debug_printf("b_peek: got a %d\n", *i->p);
return *i->p;
}
static void setup_file_in_str(struct in_str *i, FILE *f)
{
i->peek = file_peek;
i->get = file_get;
#if ENABLE_HUSH_INTERACTIVE
i->__promptme = 1;
i->promptmode = 1;
#endif
i->file = f;
i->p = NULL;
}
static void setup_string_in_str(struct in_str *i, const char *s)
{
i->peek = static_peek;
i->get = static_get;
#if ENABLE_HUSH_INTERACTIVE
i->__promptme = 1;
i->promptmode = 1;
#endif
i->p = s;
}
static void mark_open(int fd)
{
struct close_me *new = xmalloc(sizeof(struct close_me));
new->fd = fd;
new->next = close_me_head;
close_me_head = new;
}
static void mark_closed(int fd)
{
struct close_me *tmp;
if (close_me_head == NULL || close_me_head->fd != fd)
bb_error_msg_and_die("corrupt close_me");
tmp = close_me_head;
close_me_head = close_me_head->next;
free(tmp);
}
static void close_all(void)
{
struct close_me *c;
for (c = close_me_head; c; c = c->next) {
close(c->fd);
}
close_me_head = NULL;
}
/* squirrel != NULL means we squirrel away copies of stdin, stdout,
* and stderr if they are redirected. */
static int setup_redirects(struct child_prog *prog, int squirrel[])
{
int openfd, mode;
struct redir_struct *redir;
for (redir = prog->redirects; redir; redir = redir->next) {
if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
/* something went wrong in the parse. Pretend it didn't happen */
continue;
}
if (redir->dup == -1) {
mode = redir_table[redir->type].mode;
openfd = open_or_warn(redir->word.gl_pathv[0], mode);
if (openfd < 0) {
/* this could get lost if stderr has been redirected, but
bash and ash both lose it as well (though zsh doesn't!) */
return 1;
}
} else {
openfd = redir->dup;
}
if (openfd != redir->fd) {
if (squirrel && redir->fd < 3) {
squirrel[redir->fd] = dup(redir->fd);
}
if (openfd == -3) {
close(openfd);
} else {
dup2(openfd, redir->fd);
if (redir->dup == -1)
close(openfd);
}
}
}
return 0;
}
static void restore_redirects(int squirrel[])
{
int i, fd;
for (i = 0; i < 3; i++) {
fd = squirrel[i];
if (fd != -1) {
/* No error checking. I sure wouldn't know what
* to do with an error if I found one! */
dup2(fd, i);
close(fd);
}
}
}
/* never returns */
/* XXX no exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
* in particular stdin handling. Not sure why? -- because of vfork! (vda) */
static void pseudo_exec_argv(char **argv)
{
int i, rcode;
char *p;
const struct built_in_command *x;
for (i = 0; is_assignment(argv[i]); i++) {
debug_printf("pid %d environment modification: %s\n",
getpid(), argv[i]);
// FIXME: vfork case??
p = insert_var_value(argv[i]);
putenv(strdup(p));
if (p != argv[i])
free(p);
}
argv += i;
/* If a variable is assigned in a forest, and nobody listens,
* was it ever really set?
*/
if (argv[0] == NULL) {
_exit(EXIT_SUCCESS);
}
/*
* Check if the command matches any of the builtins.
* Depending on context, this might be redundant. But it's
* easier to waste a few CPU cycles than it is to figure out
* if this is one of those cases.
*/
for (x = bltins; x->cmd; x++) {
if (strcmp(argv[0], x->cmd) == 0) {
debug_printf("builtin exec %s\n", argv[0]);
rcode = x->function(argv);
fflush(stdout);
_exit(rcode);
}
}
/* Check if the command matches any busybox internal commands
* ("applets") here.
* FIXME: This feature is not 100% safe, since
* BusyBox is not fully reentrant, so we have no guarantee the things
* from the .bss are still zeroed, or that things from .data are still
* at their defaults. We could exec ourself from /proc/self/exe, but I
* really dislike relying on /proc for things. We could exec ourself
* from global_argv[0], but if we are in a chroot, we may not be able
* to find ourself... */
#if ENABLE_FEATURE_SH_STANDALONE
debug_printf("running applet %s\n", argv[0]);
run_applet_and_exit(argv[0], argv);
// is it ok that run_applet_and_exit() does exit(), not _exit()?
// NB: IIRC on NOMMU we are after _vfork_, not fork!
#endif
debug_printf("exec of %s\n", argv[0]);
execvp(argv[0], argv);
bb_perror_msg("cannot exec '%s'", argv[0]);
_exit(1);
}
static void pseudo_exec(struct child_prog *child)
{
// FIXME: buggy wrt NOMMU! Must not modify any global data
// until it does exec/_exit, but currently it does.
int rcode;
if (child->argv) {
pseudo_exec_argv(child->argv);
}
if (child->group) {
// FIXME: do not modify globals! Think vfork!
#if ENABLE_HUSH_INTERACTIVE
interactive_fd = 0; /* crucial!!!! */
#endif
debug_printf_exec("pseudo_exec: run_list_real\n");
rcode = run_list_real(child->group);
/* OK to leak memory by not calling free_pipe_list,
* since this process is about to exit */
_exit(rcode);
}
/* Can happen. See what bash does with ">foo" by itself. */
debug_printf("trying to pseudo_exec null command\n");
_exit(EXIT_SUCCESS);
}
#if ENABLE_HUSH_JOB
static const char *get_cmdtext(struct pipe *pi)
{
char **argv;
char *p;
int len;
/* This is subtle. ->cmdtext is created only on first backgrounding.
* (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
* On subsequent bg argv can be trashed, but we won't use it */
if (pi->cmdtext)
return pi->cmdtext;
argv = pi->progs[0].argv;
if (!argv || !argv[0])
return (pi->cmdtext = xzalloc(1));
len = 0;
do len += strlen(*argv) + 1; while (*++argv);
pi->cmdtext = p = xmalloc(len);
argv = pi->progs[0].argv;
do {
len = strlen(*argv);
memcpy(p, *argv, len);
p += len;
*p++ = ' ';
} while (*++argv);
p[-1] = '\0';
return pi->cmdtext;
}
#endif
#if ENABLE_HUSH_JOB
static void insert_bg_job(struct pipe *pi)
{
struct pipe *thejob;
/* Linear search for the ID of the job to use */
pi->jobid = 1;
for (thejob = job_list; thejob; thejob = thejob->next)
if (thejob->jobid >= pi->jobid)
pi->jobid = thejob->jobid + 1;
/* add thejob to the list of running jobs */
if (!job_list) {
thejob = job_list = xmalloc(sizeof(*thejob));
} else {
for (thejob = job_list; thejob->next; thejob = thejob->next)
continue;
thejob->next = xmalloc(sizeof(*thejob));
thejob = thejob->next;
}
/* physically copy the struct job */
memcpy(thejob, pi, sizeof(struct pipe));
thejob->progs = xmalloc(sizeof(pi->progs[0]) * pi->num_progs);
memcpy(thejob->progs, pi->progs, sizeof(pi->progs[0]) * pi->num_progs);
thejob->next = NULL;
/*seems to be wrong:*/
/*thejob->running_progs = thejob->num_progs;*/
/*thejob->stopped_progs = 0;*/
thejob->cmdtext = xstrdup(get_cmdtext(pi));
/* we don't wait for background thejobs to return -- append it
to the list of backgrounded thejobs and leave it alone */
printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
last_bg_pid = thejob->progs[0].pid;
last_jobid = thejob->jobid;
}
static void remove_bg_job(struct pipe *pi)
{
struct pipe *prev_pipe;
if (pi == job_list) {
job_list = pi->next;
} else {
prev_pipe = job_list;
while (prev_pipe->next != pi)
prev_pipe = prev_pipe->next;
prev_pipe->next = pi->next;
}
if (job_list)
last_jobid = job_list->jobid;
else
last_jobid = 0;
}
/* remove a backgrounded job */
static void delete_finished_bg_job(struct pipe *pi)
{
remove_bg_job(pi);
pi->stopped_progs = 0;
free_pipe(pi, 0);
free(pi);
}
#endif
/* Checks to see if any processes have exited -- if they
have, figure out why and see if a job has completed */
static int checkjobs(struct pipe* fg_pipe)
{
int attributes;
int status;
#if ENABLE_HUSH_JOB
int prognum = 0;
struct pipe *pi;
#endif
pid_t childpid;
int rcode = 0;
attributes = WUNTRACED;
if (fg_pipe == NULL) {
attributes |= WNOHANG;
}
/* Do we do this right?
* bash-3.00# sleep 20 | false
* <ctrl-Z pressed>
* [3]+ Stopped sleep 20 | false
* bash-3.00# echo $?
* 1 <========== bg pipe is not fully done, but exitcode is already known!
*/
//FIXME: non-interactive bash does not continue even if all processes in fg pipe
//are stopped. Testcase: "cat | cat" in a script (not on command line)
// + killall -STOP cat
wait_more:
while ((childpid = waitpid(-1, &status, attributes)) > 0) {
const int dead = WIFEXITED(status) || WIFSIGNALED(status);
#ifdef DEBUG_SHELL_JOBS
if (WIFSTOPPED(status))
debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
childpid, WSTOPSIG(status), WEXITSTATUS(status));
if (WIFSIGNALED(status))
debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
childpid, WTERMSIG(status), WEXITSTATUS(status));
if (WIFEXITED(status))
debug_printf_jobs("pid %d exited, exitcode %d\n",
childpid, WEXITSTATUS(status));
#endif
/* Were we asked to wait for fg pipe? */
if (fg_pipe) {
int i;
for (i = 0; i < fg_pipe->num_progs; i++) {
debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
if (fg_pipe->progs[i].pid == childpid) {
/* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
if (dead) {
fg_pipe->progs[i].pid = 0;
fg_pipe->running_progs--;
if (i == fg_pipe->num_progs-1)
/* last process gives overall exitstatus */
rcode = WEXITSTATUS(status);
} else {
fg_pipe->progs[i].is_stopped = 1;
fg_pipe->stopped_progs++;
}
debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
fg_pipe->running_progs, fg_pipe->stopped_progs);
if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
/* All processes in fg pipe have exited/stopped */
#if ENABLE_HUSH_JOB
if (fg_pipe->running_progs)
insert_bg_job(fg_pipe);
#endif
return rcode;
}
/* There are still running processes in the fg pipe */
goto wait_more;
}
}
/* fall through to searching process in bg pipes */
}
#if ENABLE_HUSH_JOB
/* We asked to wait for bg or orphaned children */
/* No need to remember exitcode in this case */
for (pi = job_list; pi; pi = pi->next) {
prognum = 0;
while (prognum < pi->num_progs) {
if (pi->progs[prognum].pid == childpid)
goto found_pi_and_prognum;
prognum++;
}
}
#endif
/* Happens when shell is used as init process (init=/bin/sh) */
debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
goto wait_more;
#if ENABLE_HUSH_JOB
found_pi_and_prognum:
if (dead) {
/* child exited */
pi->progs[prognum].pid = 0;
pi->running_progs--;
if (!pi->running_progs) {
printf(JOB_STATUS_FORMAT, pi->jobid,
"Done", pi->cmdtext);
delete_finished_bg_job(pi);
}
} else {
/* child stopped */
pi->stopped_progs++;
pi->progs[prognum].is_stopped = 1;
}
#endif
}
/* wait found no children or failed */
if (childpid && errno != ECHILD)
bb_perror_msg("waitpid");
/* move the shell to the foreground */
//if (interactive_fd && tcsetpgrp(interactive_fd, getpgid(0)))
// bb_perror_msg("tcsetpgrp-2");
return rcode;
}
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
{
pid_t p;
int rcode = checkjobs(fg_pipe);
/* Job finished, move the shell to the foreground */
p = getpgid(0);
debug_printf("fg'ing ourself: getpgid(0)=%d\n", (int)p);
if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
bb_perror_msg("tcsetpgrp-4a");
return rcode;
}
#endif
/* run_pipe_real() starts all the jobs, but doesn't wait for anything
* to finish. See checkjobs().
*
* return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
* is a simple builtin command, however, the action is done by the
* time run_pipe_real returns, and the exit code is provided as the
* return value.
*
* The input of the pipe is always stdin, the output is always
* stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
* because it tries to avoid running the command substitution in
* subshell, when that is in fact necessary. The subshell process
* now has its stdout directed to the input of the appropriate pipe,
* so this routine is noticeably simpler.
*/
static int run_pipe_real(struct pipe *pi)
{
int i;
int nextin, nextout;
int pipefds[2]; /* pipefds[0] is for reading */
struct child_prog *child;
const struct built_in_command *x;
char *p;
/* it is not always needed, but we aim to smaller code */
int squirrel[] = { -1, -1, -1 };
int rcode;
const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
debug_printf_exec("run_pipe_real start:\n");
nextin = 0;
#if ENABLE_HUSH_JOB
pi->pgrp = -1;
#endif
pi->running_progs = 1;
pi->stopped_progs = 0;
/* Check if this is a simple builtin (not part of a pipe).
* Builtins within pipes have to fork anyway, and are handled in
* pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
*/
child = &(pi->progs[0]);
if (single_fg && child->group && child->subshell == 0) {
debug_printf("non-subshell grouping\n");
setup_redirects(child, squirrel);
debug_printf_exec(": run_list_real\n");
rcode = run_list_real(child->group);
restore_redirects(squirrel);
debug_printf_exec("run_pipe_real return %d\n", rcode);
return rcode;
}
if (single_fg && child->argv != NULL) {
char **argv = child->argv;
for (i = 0; is_assignment(argv[i]); i++)
continue;
if (i != 0 && argv[i] == NULL) {
/* assignments, but no command: set the local environment */
for (i = 0; argv[i] != NULL; i++) {
/* Ok, this case is tricky. We have to decide if this is a
* local variable, or an already exported variable. If it is
* already exported, we have to export the new value. If it is
* not exported, we need only set this as a local variable.
* This junk is all to decide whether or not to export this
* variable. */
int export_me = 0;
char *name, *value;
name = xstrdup(argv[i]);
debug_printf("Local environment set: %s\n", name);
value = strchr(name, '=');
if (value)
*value = 0;
if (get_local_var(name)) {
export_me = 1;
}
free(name);
p = insert_var_value(argv[i]);
set_local_var(p, export_me);
if (p != argv[i])
free(p);
}
return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
}
for (i = 0; is_assignment(argv[i]); i++) {
p = insert_var_value(argv[i]);
putenv(strdup(p));
if (p != argv[i]) {
child->sp--;
free(p);
}
}
if (child->sp) {
char *str;
str = make_string(argv + i);
debug_printf_exec(": parse_string_outer '%s'\n", str);
parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
free(str);
debug_printf_exec("run_pipe_real return %d\n", last_return_code);
return last_return_code;
}
for (x = bltins; x->cmd; x++) {
if (strcmp(argv[i], x->cmd) == 0) {
if (x->function == builtin_exec && argv[i+1] == NULL) {
debug_printf("magic exec\n");
setup_redirects(child, NULL);
return EXIT_SUCCESS;
}
debug_printf("builtin inline %s\n", argv[0]);
/* XXX setup_redirects acts on file descriptors, not FILEs.
* This is perfect for work that comes after exec().
* Is it really safe for inline use? Experimentally,
* things seem to work with glibc. */
// TODO: fflush(NULL)?
setup_redirects(child, squirrel);
debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
rcode = x->function(argv + i);
restore_redirects(squirrel);
debug_printf_exec("run_pipe_real return %d\n", rcode);
return rcode;
}
}
#if ENABLE_FEATURE_SH_STANDALONE
{
const struct bb_applet *a = find_applet_by_name(argv[i]);
if (a && a->nofork) {
setup_redirects(child, squirrel);
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv[i], argv[i+1]);
save_nofork_data(&nofork_save);
rcode = run_nofork_applet_prime(&nofork_save, a, argv);
restore_redirects(squirrel);
debug_printf_exec("run_pipe_real return %d\n", rcode);
return rcode;
}
}
#endif
}
/* Going to fork a child per each pipe member */
pi->running_progs = 0;
/* Disable job control signals for shell (parent) and
* for initial child code after fork */
set_jobctrl_sighandler(SIG_IGN);
for (i = 0; i < pi->num_progs; i++) {
child = &(pi->progs[i]);
debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
/* pipes are inserted between pairs of commands */
if ((i + 1) < pi->num_progs) {
if (pipe(pipefds) < 0)
bb_perror_msg_and_die("pipe");
nextout = pipefds[1];
} else {
nextout = 1;
pipefds[0] = -1;
}
/* XXX test for failed fork()? */
#if BB_MMU
child->pid = fork();
#else
child->pid = vfork();
#endif
if (!child->pid) { /* child */
/* Every child adds itself to new process group
* with pgid == pid of first child in pipe */
#if ENABLE_HUSH_JOB
if (interactive_fd) {
/* Don't do pgrp restore anymore on fatal signals */
set_fatal_sighandler(SIG_DFL);
if (pi->pgrp < 0) /* true for 1st process only */
pi->pgrp = getpid();
if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
/* We do it in *every* child, not just first,
* to avoid races */
tcsetpgrp(interactive_fd, pi->pgrp);
}
}
#endif
// in non-interactive case fatal sigs are already SIG_DFL
close_all();
if (nextin != 0) {
dup2(nextin, 0);
close(nextin);
}
if (nextout != 1) {
dup2(nextout, 1);
close(nextout);
}
if (pipefds[0] != -1) {
close(pipefds[0]); /* opposite end of our output pipe */
}
/* Like bash, explicit redirects override pipes,
* and the pipe fd is available for dup'ing. */
setup_redirects(child, NULL);
/* Restore default handlers just prior to exec */
set_jobctrl_sighandler(SIG_DFL);
set_misc_sighandler(SIG_DFL);
signal(SIGCHLD, SIG_DFL);
pseudo_exec(child);
}
pi->running_progs++;
#if ENABLE_HUSH_JOB
/* Second and next children need to know pid of first one */
if (pi->pgrp < 0)
pi->pgrp = child->pid;
#endif
/* Don't check for errors. The child may be dead already,
* in which case setpgid returns error code EACCES. */
//why we do it at all?? child does it itself
//if (interactive_fd)
// setpgid(child->pid, pi->pgrp);
if (nextin != 0)
close(nextin);
if (nextout != 1)
close(nextout);
/* If there isn't another process, nextin is garbage
but it doesn't matter */
nextin = pipefds[0];
}
debug_printf_exec("run_pipe_real return -1\n");
return -1;
}
#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
static const char *PIPE[] = {
[PIPE_SEQ] = "SEQ",
[PIPE_AND] = "AND",
[PIPE_OR ] = "OR",
[PIPE_BG ] = "BG",
};
static const char *RES[] = {
[RES_NONE ] = "NONE" ,
[RES_IF ] = "IF" ,
[RES_THEN ] = "THEN" ,
[RES_ELIF ] = "ELIF" ,
[RES_ELSE ] = "ELSE" ,
[RES_FI ] = "FI" ,
[RES_FOR ] = "FOR" ,
[RES_WHILE] = "WHILE",
[RES_UNTIL] = "UNTIL",
[RES_DO ] = "DO" ,
[RES_DONE ] = "DONE" ,
[RES_XXXX ] = "XXXX" ,
[RES_IN ] = "IN" ,
[RES_SNTX ] = "SNTX" ,
};
int pin, prn;
pin = 0;
while (pi) {
fprintf(stderr, "%*spipe %d r_mode=%s followup=%d %s\n", lvl*2, "",
pin, RES[pi->r_mode], pi->followup, PIPE[pi->followup]);
prn = 0;
while (prn < pi->num_progs) {
struct child_prog *child = &pi->progs[prn];
char **argv = child->argv;
fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
if (child->group) {
fprintf(stderr, " group %s: (argv=%p)\n",
(child->subshell ? "()" : "{}"),
argv);
debug_print_tree(child->group, lvl+1);
prn++;
continue;
}
if (argv) while (*argv) {
fprintf(stderr, " '%s'", *argv);
argv++;
}
fprintf(stderr, "\n");
prn++;
}
pi = pi->next;
pin++;
}
}
#endif
// NB: called by pseudo_exec, and therefore must not modify any
// global data until exec/_exit (we can be a child after vfork!)
static int run_list_real(struct pipe *pi)
{
#if ENABLE_HUSH_JOB
static int level;
#else
enum { level = 0 };
#endif
char *save_name = NULL;
char **list = NULL;
char **save_list = NULL;
struct pipe *rpipe;
int flag_rep = 0;
int save_num_progs;
int flag_skip = 1;
int rcode = 0; /* probably for gcc only */
int flag_restore = 0;
int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
debug_printf_exec("run_list_real start lvl %d\n", level + 1);
/* check syntax for "for" */
for (rpipe = pi; rpipe; rpipe = rpipe->next) {
if ((rpipe->r_mode == RES_IN || rpipe->r_mode == RES_FOR)
&& (rpipe->next == NULL)
) {
syntax();
debug_printf_exec("run_list_real lvl %d return 1\n", level);
return 1;
}
if ((rpipe->r_mode == RES_IN && rpipe->next->r_mode == RES_IN && rpipe->next->progs->argv != NULL)
|| (rpipe->r_mode == RES_FOR && rpipe->next->r_mode != RES_IN)
) {
syntax();
debug_printf_exec("run_list_real lvl %d return 1\n", level);
return 1;
}
}
#if ENABLE_HUSH_JOB
/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
* We are saving state before entering outermost list ("while...done")
* so that ctrl-Z will correctly background _entire_ outermost list,
* not just a part of it (like "sleep 1 | exit 2") */
if (++level == 1 && interactive_fd) {
if (sigsetjmp(toplevel_jb, 1)) {
/* ctrl-Z forked and we are parent; or ctrl-C.
* Sighandler has longjmped us here */
signal(SIGINT, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
/* Restore level (we can be coming from deep inside
* nested levels) */
level = 1;
#if ENABLE_FEATURE_SH_STANDALONE
if (nofork_save.saved) { /* if save area is valid */
debug_printf_jobs("exiting nofork early\n");
restore_nofork_data(&nofork_save);
}
#endif
if (ctrl_z_flag) {
/* ctrl-Z has forked and stored pid of the child in pi->pid.
* Remember this child as background job */
insert_bg_job(pi);
} else {
/* ctrl-C. We just stop doing whatever we was doing */
putchar('\n');
}
rcode = 0;
goto ret;
}
/* ctrl-Z handler will store pid etc in pi */
toplevel_list = pi;
ctrl_z_flag = 0;
#if ENABLE_FEATURE_SH_STANDALONE
nofork_save.saved = 0; /* in case we will run a nofork later */
#endif
signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
signal(SIGINT, handler_ctrl_c);
}
#endif
for (; pi; pi = flag_restore ? rpipe : pi->next) {
rmode = pi->r_mode;
if (rmode == RES_WHILE || rmode == RES_UNTIL || rmode == RES_FOR) {
flag_restore = 0;
if (!rpipe) {
flag_rep = 0;
rpipe = pi;
}
}
debug_printf_exec(": rmode=%d if_code=%d next_if_code=%d skip_more=%d\n",
rmode, if_code, next_if_code, skip_more_in_this_rmode);
if (rmode == skip_more_in_this_rmode && flag_skip) {
if (pi->followup == PIPE_SEQ)
flag_skip = 0;
continue;
}
flag_skip = 1;
skip_more_in_this_rmode = RES_XXXX;
if (rmode == RES_THEN || rmode == RES_ELSE)
if_code = next_if_code;
if (rmode == RES_THEN && if_code)
continue;
if (rmode == RES_ELSE && !if_code)
continue;
if (rmode == RES_ELIF && !if_code)
break;
if (rmode == RES_FOR && pi->num_progs) {
if (!list) {
/* if no variable values after "in" we skip "for" */
if (!pi->next->progs->argv)
continue;
/* create list of variable values */
list = make_list_in(pi->next->progs->argv,
pi->progs->argv[0]);
save_list = list;
save_name = pi->progs->argv[0];
pi->progs->argv[0] = NULL;
flag_rep = 1;
}
if (!*list) {
free(pi->progs->argv[0]);
free(save_list);
list = NULL;
flag_rep = 0;
pi->progs->argv[0] = save_name;
pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
continue;
}
/* insert new value from list for variable */
if (pi->progs->argv[0])
free(pi->progs->argv[0]);
pi->progs->argv[0] = *list++;
pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
}
if (rmode == RES_IN)
continue;
if (rmode == RES_DO) {
if (!flag_rep)
continue;
}
if (rmode == RES_DONE) {
if (flag_rep) {
flag_restore = 1;
} else {
rpipe = NULL;
}
}
if (pi->num_progs == 0)
continue;
save_num_progs = pi->num_progs; /* save number of programs */
debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs);
rcode = run_pipe_real(pi);
if (rcode != -1) {
/* We only ran a builtin: rcode was set by the return value
* of run_pipe_real(), and we don't need to wait for anything. */
} else if (pi->followup == PIPE_BG) {
/* XXX check bash's behavior with nontrivial pipes */
/* XXX compute jobid */
/* XXX what does bash do with attempts to background builtins? */
#if ENABLE_HUSH_JOB
insert_bg_job(pi);
#endif
rcode = EXIT_SUCCESS;
} else {
#if ENABLE_HUSH_JOB
if (interactive_fd) {
rcode = checkjobs_and_fg_shell(pi);
} else
#endif
{
rcode = checkjobs(pi);
}
debug_printf_exec(": checkjobs returned %d\n", rcode);
}
debug_printf_exec(": setting last_return_code=%d\n", rcode);
last_return_code = rcode;
pi->num_progs = save_num_progs; /* restore number of programs */
if (rmode == RES_IF || rmode == RES_ELIF)
next_if_code = rcode; /* can be overwritten a number of times */
if (rmode == RES_WHILE)
flag_rep = !last_return_code;
if (rmode == RES_UNTIL)
flag_rep = last_return_code;
if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
|| (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
) {
skip_more_in_this_rmode = rmode;
}
checkjobs(NULL);
}
#if ENABLE_HUSH_JOB
if (ctrl_z_flag) {
/* ctrl-Z forked somewhere in the past, we are the child,
* and now we completed running the list. Exit. */
exit(rcode);
}
ret:
level--;
#endif
debug_printf_exec("run_list_real lvl %d return %d\n", level + 1, rcode);
return rcode;
}
/* return code is the exit status of the pipe */
static int free_pipe(struct pipe *pi, int indent)
{
char **p;
struct child_prog *child;
struct redir_struct *r, *rnext;
int a, i, ret_code = 0;
if (pi->stopped_progs > 0)
return ret_code;
final_printf("%s run pipe: (pid %d)\n", indenter(indent), getpid());
for (i = 0; i < pi->num_progs; i++) {
child = &pi->progs[i];
final_printf("%s command %d:\n", indenter(indent), i);
if (child->argv) {
for (a = 0, p = child->argv; *p; a++, p++) {
final_printf("%s argv[%d] = %s\n", indenter(indent), a, *p);
}
globfree(&child->glob_result);
child->argv = NULL;
} else if (child->group) {
final_printf("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
ret_code = free_pipe_list(child->group, indent+3);
final_printf("%s end group\n", indenter(indent));
} else {
final_printf("%s (nil)\n", indenter(indent));
}
for (r = child->redirects; r; r = rnext) {
final_printf("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
if (r->dup == -1) {
/* guard against the case >$FOO, where foo is unset or blank */
if (r->word.gl_pathv) {
final_printf(" %s\n", *r->word.gl_pathv);
globfree(&r->word);
}
} else {
final_printf("&%d\n", r->dup);
}
rnext = r->next;
free(r);
}
child->redirects = NULL;
}
free(pi->progs); /* children are an array, they get freed all at once */
pi->progs = NULL;
#if ENABLE_HUSH_JOB
free(pi->cmdtext);
pi->cmdtext = NULL;
#endif
return ret_code;
}
static int free_pipe_list(struct pipe *head, int indent)
{
int rcode = 0; /* if list has no members */
struct pipe *pi, *next;
for (pi = head; pi; pi = next) {
final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
rcode = free_pipe(pi, indent);
final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
next = pi->next;
/*pi->next = NULL;*/
free(pi);
}
return rcode;
}
/* Select which version we will use */
static int run_list(struct pipe *pi)
{
int rcode = 0;
if (fake_mode == 0) {
debug_printf_exec("run_list: run_list_real with %d members\n", pi->num_progs);
rcode = run_list_real(pi);
}
/* free_pipe_list has the side effect of clearing memory
* In the long run that function can be merged with run_list_real,
* but doing that now would hobble the debugging effort. */
free_pipe_list(pi, 0);
return rcode;
}
/* The API for glob is arguably broken. This routine pushes a non-matching
* string into the output structure, removing non-backslashed backslashes.
* If someone can prove me wrong, by performing this function within the
* original glob(3) api, feel free to rewrite this routine into oblivion.
* Return code (0 vs. GLOB_NOSPACE) matches glob(3).
* XXX broken if the last character is '\\', check that before calling.
*/
static int globhack(const char *src, int flags, glob_t *pglob)
{
int cnt = 0, pathc;
const char *s;
char *dest;
for (cnt = 1, s = src; s && *s; s++) {
if (*s == '\\') s++;
cnt++;
}
dest = malloc(cnt);
if (!dest)
return GLOB_NOSPACE;
if (!(flags & GLOB_APPEND)) {
pglob->gl_pathv = NULL;
pglob->gl_pathc = 0;
pglob->gl_offs = 0;
pglob->gl_offs = 0;
}
pathc = ++pglob->gl_pathc;
pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
if (pglob->gl_pathv == NULL)
return GLOB_NOSPACE;
pglob->gl_pathv[pathc-1] = dest;
pglob->gl_pathv[pathc] = NULL;
for (s = src; s && *s; s++, dest++) {
if (*s == '\\') s++;
*dest = *s;
}
*dest = '\0';
return 0;
}
/* XXX broken if the last character is '\\', check that before calling */
static int glob_needed(const char *s)
{
for (; *s; s++) {
if (*s == '\\') s++;
if (strchr("*[?", *s)) return 1;
}
return 0;
}
static int xglob(o_string *dest, int flags, glob_t *pglob)
{
int gr;
/* short-circuit for null word */
/* we can code this better when the debug_printf's are gone */
if (dest->length == 0) {
if (dest->nonnull) {
/* bash man page calls this an "explicit" null */
gr = globhack(dest->data, flags, pglob);
debug_printf("globhack returned %d\n", gr);
} else {
return 0;
}
} else if (glob_needed(dest->data)) {
gr = glob(dest->data, flags, NULL, pglob);
debug_printf("glob returned %d\n", gr);
if (gr == GLOB_NOMATCH) {
/* quote removal, or more accurately, backslash removal */
gr = globhack(dest->data, flags, pglob);
debug_printf("globhack returned %d\n", gr);
}
} else {
gr = globhack(dest->data, flags, pglob);
debug_printf("globhack returned %d\n", gr);
}
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die("out of memory during glob");
if (gr != 0) { /* GLOB_ABORTED ? */
bb_error_msg("glob(3) error %d", gr);
}
/* globprint(glob_target); */
return gr;
}
static char **make_list_in(char **inp, char *name)
{
int len, i;
int name_len = strlen(name);
int n = 0;
char **list;
char *p1, *p2, *p3;
/* create list of variable values */
list = xmalloc(sizeof(*list));
for (i = 0; inp[i]; i++) {
p3 = insert_var_value(inp[i]);
p1 = p3;
while (*p1) {
if ((*p1 == ' ')) {
p1++;
continue;
}
p2 = strchr(p1, ' ');
if (p2) {
len = p2 - p1;
} else {
len = strlen(p1);
p2 = p1 + len;
}
/* we use n + 2 in realloc for list, because we add
* new element and then we will add NULL element */
list = xrealloc(list, sizeof(*list) * (n + 2));
list[n] = xmalloc(2 + name_len + len);
strcpy(list[n], name);
strcat(list[n], "=");
strncat(list[n], p1, len);
list[n++][name_len + len + 1] = '\0';
p1 = p2;
}
if (p3 != inp[i]) free(p3);
}
list[n] = NULL;
return list;
}
static char *insert_var_value(char *inp)
{
int res_str_len = 0;
int len;
int done = 0;
char *p, *res_str = NULL;
const char *p1;
while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
if (p != inp) {
len = p - inp;
res_str = xrealloc(res_str, (res_str_len + len));
strncpy((res_str + res_str_len), inp, len);
res_str_len += len;
}
inp = ++p;
p = strchr(inp, SPECIAL_VAR_SYMBOL);
*p = '\0';
p1 = lookup_param(inp);
if (p1) {
len = res_str_len + strlen(p1);
res_str = xrealloc(res_str, (1 + len));
strcpy((res_str + res_str_len), p1);
res_str_len = len;
}
*p = SPECIAL_VAR_SYMBOL;
inp = ++p;
done = 1;
}
if (done) {
res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
strcpy((res_str + res_str_len), inp);
while ((p = strchr(res_str, '\n'))) {
*p = ' ';
}
}
return (res_str == NULL) ? inp : res_str;
}
/* This is used to get/check local shell variables */
static const char *get_local_var(const char *s)
{
struct variables *cur;
if (!s)
return NULL;
for (cur = top_vars; cur; cur = cur->next)
if (strcmp(cur->name, s) == 0)
return cur->value;
return NULL;
}
/* This is used to set local shell variables
flg_export == 0 if only local (not exporting) variable
flg_export == 1 if "new" exporting environ
flg_export > 1 if current startup environ (not call putenv()) */
static int set_local_var(const char *s, int flg_export)
{
char *name, *value;
int result = 0;
struct variables *cur;
name = strdup(s);
/* Assume when we enter this function that we are already in
* NAME=VALUE format. So the first order of business is to
* split 's' on the '=' into 'name' and 'value' */
value = strchr(name, '=');
/*if (value == 0 && ++value == 0) ??? -vda */
if (value == NULL || value[1] == '\0') {
free(name);
return -1;
}
*value++ = '\0';
for (cur = top_vars; cur; cur = cur->next) {
if (strcmp(cur->name, name) == 0)
break;
}
if (cur) {
if (strcmp(cur->value, value) == 0) {
if (flg_export > 0 && cur->flg_export == 0)
cur->flg_export = flg_export;
else
result++;
} else if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", name);
result = -1;
} else {
if (flg_export > 0 || cur->flg_export > 1)
cur->flg_export = 1;
free((char*)cur->value);
cur->value = strdup(value);
}
} else {
cur = malloc(sizeof(struct variables));
if (!cur) {
result = -1;
} else {
cur->name = strdup(name);
if (cur->name) {
free(cur);
result = -1;
} else {
struct variables *bottom = top_vars;
cur->value = strdup(value);
cur->next = 0;
cur->flg_export = flg_export;
cur->flg_read_only = 0;
while (bottom->next)
bottom = bottom->next;
bottom->next = cur;
}
}
}
if (result == 0 && cur->flg_export == 1) {
*(value-1) = '=';
result = putenv(name);
} else {
free(name);
if (result > 0) /* equivalent to previous set */
result = 0;
}
return result;
}
static void unset_local_var(const char *name)
{
struct variables *cur, *next;
if (!name)
return;
for (cur = top_vars; cur; cur = cur->next) {
if (strcmp(cur->name, name) == 0) {
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", name);
return;
}
if (cur->flg_export)
unsetenv(cur->name);
free((char*)cur->name);
free((char*)cur->value);
next = top_vars;
while (next->next != cur)
next = next->next;
next->next = cur->next;
free(cur);
return;
}
}
}
static int is_assignment(const char *s)
{
if (!s || !isalpha(*s))
return 0;
s++;
while (isalnum(*s) || *s == '_')
s++;
return *s == '=';
}
/* the src parameter allows us to peek forward to a possible &n syntax
* for file descriptor duplication, e.g., "2>&1".
* Return code is 0 normally, 1 if a syntax error is detected in src.
* Resource errors (in xmalloc) cause the process to exit */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
struct in_str *input)
{
struct child_prog *child = ctx->child;
struct redir_struct *redir = child->redirects;
struct redir_struct *last_redir = NULL;
/* Create a new redir_struct and drop it onto the end of the linked list */
while (redir) {
last_redir = redir;
redir = redir->next;
}
redir = xmalloc(sizeof(struct redir_struct));
redir->next = NULL;
redir->word.gl_pathv = NULL;
if (last_redir) {
last_redir->next = redir;
} else {
child->redirects = redir;
}
redir->type = style;
redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
/* Check for a '2>&1' type redirect */
redir->dup = redirect_dup_num(input);
if (redir->dup == -2) return 1; /* syntax error */
if (redir->dup != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* We do _not_ try to open the file that src points to,
* since we need to return and let src be expanded first.
* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word.
*/
ctx->pending_redirect = redir;
}
return 0;
}
static struct pipe *new_pipe(void)
{
struct pipe *pi;
pi = xzalloc(sizeof(struct pipe));
/*pi->num_progs = 0;*/
/*pi->progs = NULL;*/
/*pi->next = NULL;*/
/*pi->followup = 0; invalid */
if (RES_NONE)
pi->r_mode = RES_NONE;
return pi;
}
static void initialize_context(struct p_context *ctx)
{
ctx->pipe = NULL;
ctx->pending_redirect = NULL;
ctx->child = NULL;
ctx->list_head = new_pipe();
ctx->pipe = ctx->list_head;
ctx->res_w = RES_NONE;
ctx->stack = NULL;
ctx->old_flag = 0;
done_command(ctx); /* creates the memory for working child */
}
/* normal return is 0
* if a reserved word is found, and processed, return 1
* should handle if, then, elif, else, fi, for, while, until, do, done.
* case, function, and select are obnoxious, save those for later.
*/
static int reserved_word(o_string *dest, struct p_context *ctx)
{
struct reserved_combo {
char literal[7];
unsigned char code;
int flag;
};
/* Mostly a list of accepted follow-up reserved words.
* FLAG_END means we are done with the sequence, and are ready
* to turn the compound list into a command.
* FLAG_START means the word must start a new compound list.
*/
static const struct reserved_combo reserved_list[] = {
{ "if", RES_IF, FLAG_THEN | FLAG_START },
{ "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
{ "elif", RES_ELIF, FLAG_THEN },
{ "else", RES_ELSE, FLAG_FI },
{ "fi", RES_FI, FLAG_END },
{ "for", RES_FOR, FLAG_IN | FLAG_START },
{ "while", RES_WHILE, FLAG_DO | FLAG_START },
{ "until", RES_UNTIL, FLAG_DO | FLAG_START },
{ "in", RES_IN, FLAG_DO },
{ "do", RES_DO, FLAG_DONE },
{ "done", RES_DONE, FLAG_END }
};
enum { NRES = sizeof(reserved_list)/sizeof(reserved_list[0]) };
const struct reserved_combo *r;
for (r = reserved_list; r < reserved_list + NRES; r++) {
if (strcmp(dest->data, r->literal) == 0) {
debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
if (r->flag & FLAG_START) {
struct p_context *new = xmalloc(sizeof(struct p_context));
debug_printf("push stack\n");
if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
syntax();
free(new);
ctx->res_w = RES_SNTX;
b_reset(dest);
return 1;
}
*new = *ctx; /* physical copy */
initialize_context(ctx);
ctx->stack = new;
} else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
syntax();
ctx->res_w = RES_SNTX;
b_reset(dest);
return 1;
}
ctx->res_w = r->code;
ctx->old_flag = r->flag;
if (ctx->old_flag & FLAG_END) {
struct p_context *old;
debug_printf("pop stack\n");
done_pipe(ctx, PIPE_SEQ);
old = ctx->stack;
old->child->group = ctx->list_head;
old->child->subshell = 0;
*ctx = *old; /* physical copy */
free(old);
}
b_reset(dest);
return 1;
}
}
return 0;
}
/* Normal return is 0.
* Syntax or xglob errors return 1. */
static int done_word(o_string *dest, struct p_context *ctx)
{
struct child_prog *child = ctx->child;
glob_t *glob_target;
int gr, flags = 0;
debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
if (dest->length == 0 && !dest->nonnull) {
debug_printf_parse("done_word return 0: true null, ignored\n");
return 0;
}
if (ctx->pending_redirect) {
glob_target = &ctx->pending_redirect->word;
} else {
if (child->group) {
syntax();
debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
return 1;
}
if (!child->argv && (ctx->parse_type & FLAG_PARSE_SEMICOLON)) {
debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
if (reserved_word(dest, ctx)) {
debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
return (ctx->res_w == RES_SNTX);
}
}
glob_target = &child->glob_result;
if (child->argv)
flags |= GLOB_APPEND;
}
gr = xglob(dest, flags, glob_target);
if (gr != 0) {
debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
return 1;
}
b_reset(dest);
if (ctx->pending_redirect) {
ctx->pending_redirect = NULL;
if (glob_target->gl_pathc != 1) {
bb_error_msg("ambiguous redirect");
debug_printf_parse("done_word return 1: ambiguous redirect\n");
return 1;
}
} else {
child->argv = glob_target->gl_pathv;
}
if (ctx->res_w == RES_FOR) {
done_word(dest, ctx);
done_pipe(ctx, PIPE_SEQ);
}
debug_printf_parse("done_word return 0\n");
return 0;
}
/* The only possible error here is out of memory, in which case
* xmalloc exits. */
static int done_command(struct p_context *ctx)
{
/* The child is really already in the pipe structure, so
* advance the pipe counter and make a new, null child. */
struct pipe *pi = ctx->pipe;
struct child_prog *child = ctx->child;
if (child) {
if (child->group == NULL
&& child->argv == NULL
&& child->redirects == NULL
) {
debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
return pi->num_progs;
}
pi->num_progs++;
debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
} else {
debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
}
/* Only real trickiness here is that the uncommitted
* child structure is not counted in pi->num_progs. */
pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
child = &pi->progs[pi->num_progs];
memset(child, 0, sizeof(*child));
/*child->redirects = NULL;*/
/*child->argv = NULL;*/
/*child->is_stopped = 0;*/
/*child->group = NULL;*/
/*child->glob_result.gl_pathv = NULL;*/
child->family = pi;
/*child->sp = 0;*/
child->type = ctx->parse_type;
ctx->child = child;
/* but ctx->pipe and ctx->list_head remain unchanged */
return pi->num_progs; /* used only for 0/nonzero check */
}
static int done_pipe(struct p_context *ctx, pipe_style type)
{
struct pipe *new_p;
int not_null;
debug_printf_parse("done_pipe entered, followup %d\n", type);
not_null = done_command(ctx); /* implicit closure of previous command */
ctx->pipe->followup = type;
ctx->pipe->r_mode = ctx->res_w;
/* Without this check, even just <enter> on command line generates
* tree of three NOPs (!). Which is harmless but annoying.
* IOW: it is safe to do it unconditionally. */
if (not_null) {
new_p = new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
ctx->child = NULL;
done_command(ctx); /* set up new pipe to accept commands */
}
debug_printf_parse("done_pipe return 0\n");
return 0;
}
/* peek ahead in the in_str to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* returns either -2 (syntax error), -1 (no &), or the number found.
*/
static int redirect_dup_num(struct in_str *input)
{
int ch, d = 0, ok = 0;
ch = b_peek(input);
if (ch != '&') return -1;
b_getch(input); /* get the & */
ch = b_peek(input);
if (ch == '-') {
b_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
b_getch(input);
ch = b_peek(input);
}
if (ok) return d;
bb_error_msg("ambiguous redirect");
return -2;
}
/* If a redirect is immediately preceded by a number, that number is
* supposed to tell which file descriptor to redirect. This routine
* looks for such preceding numbers. In an ideal world this routine
* needs to handle all the following classes of redirects...
* echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
* echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
* echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
* echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
* A -1 output from this program means no valid number was found, so the
* caller should use the appropriate default for this redirection.
*/
static int redirect_opt_num(o_string *o)
{
int num;
if (o->length == 0)
return -1;
for (num = 0; num < o->length; num++) {
if (!isdigit(*(o->data + num))) {
return -1;
}
}
/* reuse num (and save an int) */
num = atoi(o->data);
b_reset(o);
return num;
}
static FILE *generate_stream_from_list(struct pipe *head)
{
FILE *pf;
int pid, channel[2];
if (pipe(channel) < 0) bb_perror_msg_and_die("pipe");
#if BB_MMU
pid = fork();
#else
pid = vfork();
#endif
if (pid < 0) {
bb_perror_msg_and_die("fork");
} else if (pid == 0) {
close(channel[0]);
if (channel[1] != 1) {
dup2(channel[1], 1);
close(channel[1]);
}
_exit(run_list_real(head)); /* leaks memory */
}
debug_printf("forked child %d\n", pid);
close(channel[1]);
pf = fdopen(channel[0], "r");
debug_printf("pipe on FILE *%p\n", pf);
return pf;
}
/* this version hacked for testing purposes */
/* return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest, struct p_context *ctx,
struct in_str *input, const char *subst_end)
{
int retcode;
o_string result = NULL_O_STRING;
struct p_context inner;
FILE *p;
struct in_str pipe_str;
initialize_context(&inner);
/* recursion to generate command */
retcode = parse_stream(&result, &inner, input, subst_end);
if (retcode != 0) return retcode; /* syntax error or EOF */
done_word(&result, &inner);
done_pipe(&inner, PIPE_SEQ);
b_free(&result);
p = generate_stream_from_list(inner.list_head);
if (p == NULL) return 1;
mark_open(fileno(p));
setup_file_in_str(&pipe_str, p);
/* now send results of command back into original context */
retcode = parse_stream(dest, ctx, &pipe_str, NULL);
/* XXX In case of a syntax error, should we try to kill the child?
* That would be tough to do right, so just read until EOF. */
if (retcode == 1) {
while (b_getch(&pipe_str) != EOF)
/* discard */;
}
debug_printf("done reading from pipe, pclose()ing\n");
/* This is the step that wait()s for the child. Should be pretty
* safe, since we just read an EOF from its stdout. We could try
* to better, by using wait(), and keeping track of background jobs
* at the same time. That would be a lot of work, and contrary
* to the KISS philosophy of this program. */
mark_closed(fileno(p));
retcode = pclose(p);
free_pipe_list(inner.list_head, 0);
debug_printf("pclosed, retcode=%d\n", retcode);
/* XXX this process fails to trim a single trailing newline */
return retcode;
}
static int parse_group(o_string *dest, struct p_context *ctx,
struct in_str *input, int ch)
{
int rcode;
const char *endch = NULL;
struct p_context sub;
struct child_prog *child = ctx->child;
debug_printf_parse("parse_group entered\n");
if (child->argv) {
syntax();
debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
return 1;
}
initialize_context(&sub);
switch (ch) {
case '(':
endch = ")";
child->subshell = 1;
break;
case '{':
endch = "}";
break;
default:
syntax(); /* really logic error */
}
rcode = parse_stream(dest, &sub, input, endch);
done_word(dest, &sub); /* finish off the final word in the subcontext */
done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
child->group = sub.list_head;
debug_printf_parse("parse_group return %d\n", rcode);
return rcode;
/* child remains "open", available for possible redirects */
}
/* basically useful version until someone wants to get fancier,
* see the bash man page under "Parameter Expansion" */
static const char *lookup_param(const char *src)
{
const char *p = NULL;
if (src) {
p = getenv(src);
if (!p)
p = get_local_var(src);
}
return p;
}
/* Make new string for parser */
static char* make_string(char ** inp)
{
char *p;
char *str = NULL;
int n;
int len = 2;
for (n = 0; inp[n]; n++) {
p = insert_var_value(inp[n]);
str = xrealloc(str, (len + strlen(p)));
if (n) {
strcat(str, " ");
} else {
*str = '\0';
}
strcat(str, p);
len = strlen(str) + 3;
if (p != inp[n]) free(p);
}
len = strlen(str);
str[len] = '\n';
str[len+1] = '\0';
return str;
}
/* return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
{
int i, advance = 0;
char sep[] = " ";
int ch = input->peek(input); /* first character after the $ */
debug_printf("handle_dollar: ch=%c\n", ch);
if (isalpha(ch)) {
b_addchr(dest, SPECIAL_VAR_SYMBOL);
ctx->child->sp++;
while (ch = b_peek(input), isalnum(ch) || ch == '_') {
b_getch(input);
b_addchr(dest, ch);
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
i = ch - '0'; /* XXX is $0 special? */
if (i < global_argc) {
parse_string(dest, ctx, global_argv[i]); /* recursion */
}
advance = 1;
} else switch (ch) {
case '$':
b_adduint(dest, getpid());
advance = 1;
break;
case '!':
if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
advance = 1;
break;
case '?':
b_adduint(dest, last_return_code);
advance = 1;
break;
case '#':
b_adduint(dest, global_argc ? global_argc-1 : 0);
advance = 1;
break;
case '{':
b_addchr(dest, SPECIAL_VAR_SYMBOL);
ctx->child->sp++;
b_getch(input);
/* XXX maybe someone will try to escape the '}' */
while (1) {
ch = b_getch(input);
if (ch == EOF || ch == '}')
break;
b_addchr(dest, ch);
}
if (ch != '}') {
syntax();
return 1;
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
case '(':
b_getch(input);
process_command_subs(dest, ctx, input, ")");
break;
case '*':
sep[0] = ifs[0];
for (i = 1; i < global_argc; i++) {
parse_string(dest, ctx, global_argv[i]);
if (i+1 < global_argc)
parse_string(dest, ctx, sep);
}
break;
case '@':
case '-':
case '_':
/* still unhandled, but should be eventually */
bb_error_msg("unhandled syntax: $%c", ch);
return 1;
break;
default:
b_addqchr(dest,'$', dest->quote);
}
/* Eat the character if the flag was set. If the compiler
* is smart enough, we could substitute "b_getch(input);"
* for all the "advance = 1;" above, and also end up with
* a nice size-optimized program. Hah! That'll be the day.
*/
if (advance) b_getch(input);
return 0;
}
static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
{
struct in_str foo;
setup_string_in_str(&foo, src);
return parse_stream(dest, ctx, &foo, NULL);
}
/* return code is 0 for normal exit, 1 for syntax error */
static int parse_stream(o_string *dest, struct p_context *ctx,
struct in_str *input, const char *end_trigger)
{
int ch, m;
int redir_fd;
redir_type redir_style;
int next;
/* Only double-quote state is handled in the state variable dest->quote.
* A single-quote triggers a bypass of the main loop until its mate is
* found. When recursing, quote state is passed in via dest->quote. */
debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
while ((ch = b_getch(input)) != EOF) {
m = map[ch];
next = (ch == '\n') ? 0 : b_peek(input);
debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
ch, ch, m, dest->quote);
if (m == MAP_ORDINARY
|| (m != MAP_NEVER_FLOWTROUGH && dest->quote)
) {
b_addqchr(dest, ch, dest->quote);
continue;
}
if (m == MAP_IFS_IF_UNQUOTED) {
if (done_word(dest, ctx)) {
debug_printf_parse("parse_stream return 1: done_word!=0\n");
return 1;
}
/* If we aren't performing a substitution, treat
* a newline as a command separator.
* [why we don't handle it exactly like ';'? --vda] */
if (end_trigger && ch == '\n') {
done_pipe(ctx, PIPE_SEQ);
}
}
if ((end_trigger && strchr(end_trigger, ch))
&& !dest->quote && ctx->res_w == RES_NONE
) {
debug_printf_parse("parse_stream return 0: end_trigger char found\n");
return 0;
}
if (m == MAP_IFS_IF_UNQUOTED)
continue;
switch (ch) {
case '#':
if (dest->length == 0 && !dest->quote) {
while (1) {
ch = b_peek(input);
if (ch == EOF || ch == '\n')
break;
b_getch(input);
}
} else {
b_addqchr(dest, ch, dest->quote);
}
break;
case '\\':
if (next == EOF) {
syntax();
debug_printf_parse("parse_stream return 1: \\<eof>\n");
return 1;
}
b_addqchr(dest, '\\', dest->quote);
b_addqchr(dest, b_getch(input), dest->quote);
break;
case '$':
if (handle_dollar(dest, ctx, input) != 0) {
debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
return 1;
}
break;
case '\'':
dest->nonnull = 1;
while (1) {
ch = b_getch(input);
if (ch == EOF || ch == '\'')
break;
b_addchr(dest, ch);
}
if (ch == EOF) {
syntax();
debug_printf_parse("parse_stream return 1: unterminated '\n");
return 1;
}
break;
case '"':
dest->nonnull = 1;
dest->quote = !dest->quote;
break;
case '`':
process_command_subs(dest, ctx, input, "`");
break;
case '>':
redir_fd = redirect_opt_num(dest);
done_word(dest, ctx);
redir_style = REDIRECT_OVERWRITE;
if (next == '>') {
redir_style = REDIRECT_APPEND;
b_getch(input);
} else if (next == '(') {
syntax(); /* until we support >(list) Process Substitution */
debug_printf_parse("parse_stream return 1: >(process) not supported\n");
return 1;
}
setup_redirect(ctx, redir_fd, redir_style, input);
break;
case '<':
redir_fd = redirect_opt_num(dest);
done_word(dest, ctx);
redir_style = REDIRECT_INPUT;
if (next == '<') {
redir_style = REDIRECT_HEREIS;
b_getch(input);
} else if (next == '>') {
redir_style = REDIRECT_IO;
b_getch(input);
} else if (next == '(') {
syntax(); /* until we support <(list) Process Substitution */
debug_printf_parse("parse_stream return 1: <(process) not supported\n");
return 1;
}
setup_redirect(ctx, redir_fd, redir_style, input);
break;
case ';':
done_word(dest, ctx);
done_pipe(ctx, PIPE_SEQ);
break;
case '&':
done_word(dest, ctx);
if (next == '&') {
b_getch(input);
done_pipe(ctx, PIPE_AND);
} else {
done_pipe(ctx, PIPE_BG);
}
break;
case '|':
done_word(dest, ctx);
if (next == '|') {
b_getch(input);
done_pipe(ctx, PIPE_OR);
} else {
/* we could pick up a file descriptor choice here
* with redirect_opt_num(), but bash doesn't do it.
* "echo foo 2| cat" yields "foo 2". */
done_command(ctx);
}
break;
case '(':
case '{':
if (parse_group(dest, ctx, input, ch) != 0) {
debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
return 1;
}
break;
case ')':
case '}':
syntax(); /* Proper use of this character is caught by end_trigger */
debug_printf_parse("parse_stream return 1: unexpected '}'\n");
return 1;
default:
syntax(); /* this is really an internal logic error */
debug_printf_parse("parse_stream return 1: internal logic error\n");
return 1;
}
}
/* Complain if quote? No, maybe we just finished a command substitution
* that was quoted. Example:
* $ echo "`cat foo` plus more"
* and we just got the EOF generated by the subshell that ran "cat foo"
* The only real complaint is if we got an EOF when end_trigger != NULL,
* that is, we were really supposed to get end_trigger, and never got
* one before the EOF. Can't use the standard "syntax error" return code,
* so that parse_stream_outer can distinguish the EOF and exit smoothly. */
debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
if (end_trigger)
return -1;
return 0;
}
static void mapset(const char *set, int code)
{
while (*set)
map[(unsigned char)*set++] = code;
}
static void update_ifs_map(void)
{
/* char *ifs and char map[256] are both globals. */
ifs = getenv("IFS");
if (ifs == NULL)
ifs = " \t\n";
/* Precompute a list of 'flow through' behavior so it can be treated
* quickly up front. Computation is necessary because of IFS.
* Special case handling of IFS == " \t\n" is not implemented.
* The map[] array only really needs two bits each, and on most machines
* that would be faster because of the reduced L1 cache footprint.
*/
memset(map, MAP_ORDINARY, sizeof(map)); /* most chars flow through always */
mapset("\\$'\"`", MAP_NEVER_FLOWTROUGH);
mapset("<>;&|(){}#", MAP_FLOWTROUGH_IF_QUOTED);
mapset(ifs, MAP_IFS_IF_UNQUOTED); /* also flow through if quoted */
}
/* most recursion does not come through here, the exception is
* from builtin_source() */
static int parse_stream_outer(struct in_str *inp, int parse_flag)
{
// FIXME: '{ true | exit 3; echo $? }' is parsed as a whole,
// as a result $? is replaced by 0, not 3!
struct p_context ctx;
o_string temp = NULL_O_STRING;
int rcode;
do {
ctx.parse_type = parse_flag;
initialize_context(&ctx);
update_ifs_map();
if (!(parse_flag & FLAG_PARSE_SEMICOLON) || (parse_flag & FLAG_REPARSING))
mapset(";$&|", MAP_ORDINARY);
#if ENABLE_HUSH_INTERACTIVE
inp->promptmode = 1;
#endif
/* We will stop & execute after each ';' or '\n'.
* Example: "sleep 9999; echo TEST" + ctrl-C:
* TEST should be printed */
rcode = parse_stream(&temp, &ctx, inp, ";\n");
if (rcode != 1 && ctx.old_flag != 0) {
syntax();
}
if (rcode != 1 && ctx.old_flag == 0) {
done_word(&temp, &ctx);
done_pipe(&ctx, PIPE_SEQ);
debug_printf_exec("parse_stream_outer: run_list\n");
debug_print_tree(ctx.list_head, 0);
run_list(ctx.list_head);
} else {
if (ctx.old_flag != 0) {
free(ctx.stack);
b_reset(&temp);
}
temp.nonnull = 0;
temp.quote = 0;
inp->p = NULL;
free_pipe_list(ctx.list_head, 0);
}
b_free(&temp);
} while (rcode != -1 && !(parse_flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
return 0;
}
static int parse_string_outer(const char *s, int parse_flag)
{
struct in_str input;
setup_string_in_str(&input, s);
return parse_stream_outer(&input, parse_flag);
}
static int parse_file_outer(FILE *f)
{
int rcode;
struct in_str input;
setup_file_in_str(&input, f);
rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
return rcode;
}
#if ENABLE_HUSH_JOB
/* Make sure we have a controlling tty. If we get started under a job
* aware app (like bash for example), make sure we are now in charge so
* we don't fight over who gets the foreground */
static void setup_job_control(void)
{
pid_t shell_pgrp;
saved_task_pgrp = shell_pgrp = getpgrp();
debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
/* If we were ran as 'hush &',
* sleep until we are in the foreground. */
while (tcgetpgrp(interactive_fd) != shell_pgrp) {
/* Send TTIN to ourself (should stop us) */
kill(- shell_pgrp, SIGTTIN);
shell_pgrp = getpgrp();
}
/* Ignore job-control and misc signals. */
set_jobctrl_sighandler(SIG_IGN);
set_misc_sighandler(SIG_IGN);
//huh? signal(SIGCHLD, SIG_IGN);
/* We _must_ restore tty pgrp on fatal signals */
set_fatal_sighandler(sigexit);
/* Put ourselves in our own process group. */
setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
/* Grab control of the terminal. */
tcsetpgrp(interactive_fd, getpid());
}
#endif
int hush_main(int argc, char **argv);
int hush_main(int argc, char **argv)
{
int opt;
FILE *input;
char **e;
#if ENABLE_FEATURE_EDITING
line_input_state = new_line_input_t(FOR_SHELL);
#endif
/* XXX what should these be while sourcing /etc/profile? */
global_argc = argc;
global_argv = argv;
/* (re?) initialize globals. Sometimes hush_main() ends up calling
* hush_main(), therefore we cannot rely on the BSS to zero out this
* stuff. Reset these to 0 every time. */
ifs = NULL;
/* map[] is taken care of with call to update_ifs_map() */
fake_mode = 0;
close_me_head = NULL;
#if ENABLE_HUSH_INTERACTIVE
interactive_fd = 0;
#endif
#if ENABLE_HUSH_JOB
last_bg_pid = 0;
job_list = NULL;
last_jobid = 0;
#endif
/* Initialize some more globals to non-zero values */
set_cwd();
#if ENABLE_HUSH_INTERACTIVE
#if ENABLE_FEATURE_EDITING
cmdedit_set_initial_prompt();
#else
PS1 = NULL;
#endif
PS2 = "> ";
#endif
/* initialize our shell local variables with the values
* currently living in the environment */
e = environ;
if (e)
while (*e)
set_local_var(*e++, 2); /* without call putenv() */
last_return_code = EXIT_SUCCESS;
if (argv[0] && argv[0][0] == '-') {
debug_printf("\nsourcing /etc/profile\n");
input = fopen("/etc/profile", "r");
if (input != NULL) {
mark_open(fileno(input));
parse_file_outer(input);
mark_closed(fileno(input));
fclose(input);
}
}
input = stdin;
while ((opt = getopt(argc, argv, "c:xif")) > 0) {
switch (opt) {
case 'c':
global_argv = argv + optind;
global_argc = argc - optind;
opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
goto final_return;
case 'i':
// Well, we cannot just declare interactiveness,
// we have to have some stuff (ctty, etc)
/*interactive_fd++;*/
break;
case 'f':
fake_mode++;
break;
default:
#ifndef BB_VER
fprintf(stderr, "Usage: sh [FILE]...\n"
" or: sh -c command [args]...\n\n");
exit(EXIT_FAILURE);
#else
bb_show_usage();
#endif
}
}
#if ENABLE_HUSH_JOB
/* A shell is interactive if the '-i' flag was given, or if all of
* the following conditions are met:
* no -c command
* no arguments remaining or the -s flag given
* standard input is a terminal
* standard output is a terminal
* Refer to Posix.2, the description of the 'sh' utility. */
if (argv[optind] == NULL && input == stdin
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
if (saved_tty_pgrp >= 0) {
/* try to dup to high fd#, >= 255 */
interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
if (interactive_fd < 0) {
/* try to dup to any fd */
interactive_fd = dup(STDIN_FILENO);
if (interactive_fd < 0)
/* give up */
interactive_fd = 0;
}
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect it
}
}
debug_printf("\ninteractive_fd=%d\n", interactive_fd);
if (interactive_fd) {
/* Looks like they want an interactive shell */
setup_job_control();
/* Make xfuncs do cleanup on exit */
die_sleep = -1; /* flag */
if (setjmp(die_jmp)) {
/* xfunc has failed! die die die */
hush_exit(xfunc_error_retval);
}
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", BB_BANNER);
printf("Enter 'help' for a list of built-in commands.\n\n");
#endif
}
#elif ENABLE_HUSH_INTERACTIVE
/* no job control compiled, only prompt/line editing */
if (argv[optind] == NULL && input == stdin
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
if (interactive_fd < 0) {
/* try to dup to any fd */
interactive_fd = dup(STDIN_FILENO);
if (interactive_fd < 0)
/* give up */
interactive_fd = 0;
}
}
#endif
if (argv[optind] == NULL) {
opt = parse_file_outer(stdin);
goto final_return;
}
debug_printf("\nrunning script '%s'\n", argv[optind]);
global_argv = argv + optind;
global_argc = argc - optind;
input = xfopen(argv[optind], "r");
opt = parse_file_outer(input);
#if ENABLE_FEATURE_CLEAN_UP
fclose(input);
if (cwd != bb_msg_unknown)
free((char*)cwd);
{
struct variables *cur, *tmp;
for (cur = top_vars; cur; cur = tmp) {
tmp = cur->next;
if (!cur->flg_read_only) {
free((char*)cur->name);
free((char*)cur->value);
free(cur);
}
}
}
#endif
final_return:
hush_exit(opt ? opt : last_return_code);
}