In Bug 5, Tito writes:
This is a first attempt to improve the comments of getopt_ulflags.c.
Maybe under some aspects the text could be refined, but so
far it is already usable and should help people who "avoided getopt_ulflags as the pest" to understand how it works.
This patch was created with the help of
Vodz, the author of the code, who explained me patiently
how getopt_ulflags works
and with the help of
Paul Fox, who corrected my broken english.
So thanks and merits should go to them also.
diff --git a/libbb/getopt_ulflags.c b/libbb/getopt_ulflags.c
index 39a7d1d..24bdcb6 100644
--- a/libbb/getopt_ulflags.c
+++ b/libbb/getopt_ulflags.c
@@ -26,146 +26,240 @@
#include <stdlib.h>
#include "libbb.h"
-/*
-You can set bb_opt_complementaly as string with one or more
-complementaly or incongruously options.
-If sequential founded option haved from this string
-then your incongruously pairs unsets and complementaly make add sets.
-Format:
-one char - option for check,
-chars - complementaly option for add sets.
-- chars - option triggered for unsets.
-~ chars - option incongruously.
-* - option list, called add_to_list(*ptr_from_usaged, optarg)
-: - separator.
-Example: du applet can have options "-s" and "-d size"
-If getopt found -s then -d option flag unset or if found -d then -s unset.
-For this result you must set bb_opt_complementaly = "s-d:d-s".
-Result have last option flag only from called arguments.
-Warning! You can check returned flag, pointer to "d:" argument seted
-to own optarg always.
-Example two: cut applet must only one type of list may be specified,
-and -b, -c and -f incongruously option, overwited option is error also.
-You must set bb_opt_complementaly = "b~cf:c~bf:f~bc".
-If called have more one specified, return value have error flag -
-high bite set (0x80000000UL).
-Example three: grep applet can have one or more "-e pattern" arguments.
-You should use bb_getopt_ulflags() as
-llist_t *paterns;
-bb_opt_complementaly = "e*";
-bb_getopt_ulflags (argc, argv, "e:", &paterns);
+/* Documentation !
+
+bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...)
+
+ The command line options must be declared in const char
+ *applet_opts as a string of chars, for example:
+
+ flags = bb_getopt_ulflags(argc, argv, "rnug");
+
+ If one of the given options is found a flag value is added to
+ the unsigned long returned by bb_getopt_ulflags.
+
+ The value of this flag is given by the position of the char in
+ const char *applet_opts so for example in this case:
+
+ flags = bb_getopt_ulflags(argc, argv, "rnug");
+
+ "r" will add 1
+ "n" will add 2
+ "u will add 4
+ "g" will add 8
+
+ and so on.
+
+ If an argument is required by one of the options add a ":"
+ after the char in const char *applet_opts and provide a pointer
+ where the arg could be stored if it is found, for example:
+
+ char *pointer_to_arg_for_a;
+ char *pointer_to_arg_for_b;
+ char *pointer_to_arg_for_c;
+ char *pointer_to_arg_for_d;
+
+ flags = bb_getopt_ulflags(argc, argv, "a:b:c:d:",
+ &pointer_to_arg_for_a, &pointer_to_arg_for_b,
+ &pointer_to_arg_for_c, &pointer_to_arg_for_d);
+
+ The type of the pointer (char* or llist_t *) can be influenced
+ by the "*" special character that can be set in const char
+ *bb_opt_complementaly (see below).
+
+const char *bb_opt_complementaly
+
+ ":" The colon (":") is used in bb_opt_complementaly as separator
+ between groups of two or more chars and/or groups of chars and
+ special characters (stating some conditions to be checked).
+
+ "abc" If groups of two or more chars are specified the first char
+ is the main option and the other chars are secondary options
+ whose flags will be turned on if the main option is found even
+ if they are not specifed on the command line, for example:
+
+ bb_opt_complementaly = "abc";
+
+ flags = bb_getopt_ulflags(argc, argv, "abcd")
+
+ If getopt() finds "-a" on the command line, then
+ bb_getopt_ulflags's return value will be as if "-a -b -c" were
+ found.
+
+Special characters:
+
+ "-" A dash between two options causes the second of the two
+ to be unset (and ignored) if it is given on the command line.
+
+ For example:
+ The du applet can have the options "-s" and "-d depth", if
+ bb_getopt_ulflags finds -s then -d is unset or if it finds -d
+ then -s is unset. (Note: busybox implements the GNU
+ "--max-depth" option as "-d".) In this case bb_getopt_ulflags's
+ return value has no error flag set (0x80000000UL). To achieve
+ this result you must set bb_opt_complementaly = "s-d:d-s".
+ Only one flag value is added to bb_getopt_ulflags's return
+ value depending on the position of the options on the command
+ line. If one of the two options requires an argument pointer
+ (":" in const char *applet_opts as in "d:") optarg is set
+ accordingly.
+
+ char *smax_print_depth;
+
+ bb_opt_complementaly = "s-d:d-s";
+ opt = bb_getopt_ulflags(argc, argv, "sd:" , &smax_print_depth);
+
+ if (opt & 2) {
+ max_print_depth = bb_xgetularg10_bnd(smax_print_depth,
+ 0, INT_MAX);
+ }
+
+ "~" A tilde between two options or between an option and a group
+ of options means that they are mutually exclusive. Unlike
+ the "-" case above, an error will be forced if the options
+ are used together.
+
+ For example:
+ The cut applet must have only one type of list specified, so
+ -b, -c and -f are mutally exclusive and should raise an error
+ if specified together. In this case you must set
+ bb_opt_complementaly = "b~cf:c~bf:f~bc". If two of the
+ mutually exclusive options are found, bb_getopt_ulflags's
+ return value will have the error flag set (0x80000000UL) so
+ that we can check for it:
+
+ if ((flags & 0x80000000UL)
+ bb_show_usage();
+
+ "*" A star after a char in bb_opt_complementaly means that the
+ option can occur multiple times:
+
+ For example:
+ The grep applet can have one or more "-e pattern" arguments.
+ In this case you should use bb_getopt_ulflags() as follows:
+
+ llist_t *patterns=NULL;
+
+ (this pointer must be initializated to NULL if the list is empty
+ as required by *llist_add_to(llist_t *old_head, char *new_item).)
+
+ bb_opt_complementaly = "e*";
+
+ bb_getopt_ulflags (argc, argv, "e:", &patterns);
+ grep -e user -e root /etc/passwd
+ root:x:0:0:root:/root:/bin/bash
+ user:x:500:500::/home/user:/bin/bash
+
*/
const char *bb_opt_complementaly;
-typedef struct
-{
+typedef struct {
unsigned char opt;
char list_flg;
unsigned long switch_on;
unsigned long switch_off;
unsigned long incongruously;
- void **optarg; /* char **optarg or llist_t **optarg */
+ void **optarg; /* char **optarg or llist_t **optarg */
} t_complementaly;
/* You can set bb_applet_long_options for parse called long options */
static const struct option bb_default_long_options[] = {
- /* { "help", 0, NULL, '?' }, */
+/* { "help", 0, NULL, '?' }, */
{ 0, 0, 0, 0 }
};
const struct option *bb_applet_long_options = bb_default_long_options;
-
unsigned long
bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...)
{
- unsigned long flags = 0;
- t_complementaly complementaly[sizeof(flags) * 8 + 1];
- int c;
- const unsigned char *s;
- t_complementaly *on_off;
- va_list p;
+ unsigned long flags = 0;
+ t_complementaly complementaly[sizeof(flags) * 8 + 1];
+ int c;
+ const unsigned char *s;
+ t_complementaly *on_off;
+ va_list p;
- va_start (p, applet_opts);
+ va_start (p, applet_opts);
- /* skip GNU extension */
- s = applet_opts;
- if(*s == '+' || *s == '-')
- s++;
-
- c = 0;
- on_off = complementaly;
- for (; *s; s++) {
- if(c >= (sizeof(flags)*8))
- break;
- on_off->opt = *s;
- on_off->switch_on = (1 << c);
- on_off->list_flg = 0;
- on_off->switch_off = 0;
- on_off->incongruously = 0;
- on_off->optarg = NULL;
- if (s[1] == ':') {
- on_off->optarg = va_arg (p, void **);
- do
+ /* skip GNU extension */
+ s = applet_opts;
+ if(*s == '+' || *s == '-')
s++;
- while (s[1] == ':');
- }
- on_off++;
- c++;
- }
- on_off->opt = 0;
- c = 0;
- for (s = bb_opt_complementaly; s && *s; s++) {
- t_complementaly *pair;
- if (*s == ':') {
- c = 0;
- continue;
- }
- if (c)
- continue;
- for (on_off = complementaly; on_off->opt; on_off++)
- if (on_off->opt == *s)
- break;
- pair = on_off;
- for(s++; *s && *s != ':'; s++) {
- if (*s == '-' || *s == '~') {
- c = *s;
- } else if(*s == '*') {
- pair->list_flg++;
- } else {
- unsigned long *pair_switch = &(pair->switch_on);
-
- if(c)
- pair_switch = c == '-' ? &(pair->switch_off) : &(pair->incongruously);
- for (on_off = complementaly; on_off->opt; on_off++)
- if (on_off->opt == *s) {
- *pair_switch |= on_off->switch_on;
- break;
- }
- }
- }
- s--;
- }
-
- while ((c = getopt_long (argc, argv, applet_opts,
- bb_applet_long_options, NULL)) > 0) {
- for (on_off = complementaly; on_off->opt != c; on_off++) {
- if(!on_off->opt)
- bb_show_usage ();
+ c = 0;
+ on_off = complementaly;
+ for (; *s; s++) {
+ if(c >= (sizeof(flags)*8))
+ break;
+ on_off->opt = *s;
+ on_off->switch_on = (1 << c);
+ on_off->list_flg = 0;
+ on_off->switch_off = 0;
+ on_off->incongruously = 0;
+ on_off->optarg = NULL;
+ if (s[1] == ':') {
+ on_off->optarg = va_arg (p, void **);
+ do
+ s++;
+ while (s[1] == ':');
+ }
+ on_off++;
+ c++;
}
- if(flags & on_off->incongruously)
- flags |= 0x80000000UL;
- flags &= ~on_off->switch_off;
- flags |= on_off->switch_on;
- if(on_off->list_flg) {
- *(llist_t **)(on_off->optarg) =
- llist_add_to(*(llist_t **)(on_off->optarg), optarg);
- } else if (on_off->optarg) {
- *(char **)(on_off->optarg) = optarg;
+ on_off->opt = 0;
+ c = 0;
+ for (s = bb_opt_complementaly; s && *s; s++) {
+ t_complementaly *pair;
+
+ if (*s == ':') {
+ c = 0;
+ continue;
+ }
+ if (c)
+ continue;
+ for (on_off = complementaly; on_off->opt; on_off++)
+ if (on_off->opt == *s)
+ break;
+ pair = on_off;
+ for(s++; *s && *s != ':'; s++) {
+ if (*s == '-' || *s == '~') {
+ c = *s;
+ } else if(*s == '*') {
+ pair->list_flg++;
+ } else {
+ unsigned long *pair_switch = &(pair->switch_on);
+ if(c)
+ pair_switch = c == '-' ? &(pair->switch_off) : &(pair->incongruously);
+ for (on_off = complementaly; on_off->opt; on_off++)
+ if (on_off->opt == *s) {
+ *pair_switch |= on_off->switch_on;
+ break;
+ }
+ }
+ }
+ s--;
}
- }
- return flags;
+
+ while ((c = getopt_long (argc, argv, applet_opts,
+ bb_applet_long_options, NULL)) > 0) {
+ for (on_off = complementaly; on_off->opt != c; on_off++) {
+ if(!on_off->opt)
+ bb_show_usage ();
+ }
+ if(flags & on_off->incongruously)
+ flags |= 0x80000000UL;
+ flags &= ~on_off->switch_off;
+ flags |= on_off->switch_on;
+ if(on_off->list_flg) {
+ *(llist_t **)(on_off->optarg) =
+ llist_add_to(*(llist_t **)(on_off->optarg), optarg);
+ } else if (on_off->optarg) {
+ *(char **)(on_off->optarg) = optarg;
+ }
+ }
+
+ return flags;
}