| /* vi: set sw=4 ts=4: */ |
| /* |
| * Utility routines. |
| * |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * |
| * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
| */ |
| |
| #include "libbb.h" |
| |
| /* |
| In Linux we have three ways to determine "process name": |
| 1. /proc/PID/stat has "...(name)...", among other things. It's so-called "comm" field. |
| 2. /proc/PID/cmdline's first NUL-terminated string. It's argv[0] from exec syscall. |
| 3. /proc/PID/exe symlink. Points to the running executable file. |
| |
| kernel threads: |
| comm: thread name |
| cmdline: empty |
| exe: <readlink fails> |
| |
| executable |
| comm: first 15 chars of base name |
| (if executable is a symlink, then first 15 chars of symlink name are used) |
| cmdline: argv[0] from exec syscall |
| exe: points to executable (resolves symlink, unlike comm) |
| |
| script (an executable with #!/path/to/interpreter): |
| comm: first 15 chars of script's base name (symlinks are not resolved) |
| cmdline: /path/to/interpreter (symlinks are not resolved) |
| (script name is in argv[1], args are pushed into argv[2] etc) |
| exe: points to interpreter's executable (symlinks are resolved) |
| |
| If FEATURE_PREFER_APPLETS=y (and more so if FEATURE_SH_STANDALONE=y), |
| some commands started from busybox shell, xargs or find are started by |
| execXXX("/proc/self/exe", applet_name, params....) |
| and therefore comm field contains "exe". |
| */ |
| |
| static int comm_match(procps_status_t *p, const char *procName) |
| { |
| int argv1idx; |
| |
| /* comm does not match */ |
| if (strncmp(p->comm, procName, 15) != 0) |
| return 0; |
| |
| /* in Linux, if comm is 15 chars, it may be a truncated */ |
| if (p->comm[14] == '\0') /* comm is not truncated - match */ |
| return 1; |
| |
| /* comm is truncated, but first 15 chars match. |
| * This can be crazily_long_script_name.sh! |
| * The telltale sign is basename(argv[1]) == procName. */ |
| |
| if (!p->argv0) |
| return 0; |
| |
| argv1idx = strlen(p->argv0) + 1; |
| if (argv1idx >= p->argv_len) |
| return 0; |
| |
| if (strcmp(bb_basename(p->argv0 + argv1idx), procName) != 0) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* find_pid_by_name() |
| * |
| * Modified by Vladimir Oleynik for use with libbb/procps.c |
| * This finds the pid of the specified process. |
| * Currently, it's implemented by rummaging through |
| * the proc filesystem. |
| * |
| * Returns a list of all matching PIDs |
| * It is the caller's duty to free the returned pidlist. |
| */ |
| pid_t* FAST_FUNC find_pid_by_name(const char *procName) |
| { |
| pid_t* pidList; |
| int i = 0; |
| procps_status_t* p = NULL; |
| |
| pidList = xzalloc(sizeof(*pidList)); |
| while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM|PSSCAN_ARGVN))) { |
| if (comm_match(p, procName) |
| /* or we require argv0 to match (essential for matching reexeced /proc/self/exe)*/ |
| || (p->argv0 && strcmp(bb_basename(p->argv0), procName) == 0) |
| /* TOOD: we can also try /proc/NUM/exe link, do we want that? */ |
| ) { |
| pidList = xrealloc_vector(pidList, 2, i); |
| pidList[i++] = p->pid; |
| } |
| } |
| |
| pidList[i] = 0; |
| return pidList; |
| } |
| |
| pid_t* FAST_FUNC pidlist_reverse(pid_t *pidList) |
| { |
| int i = 0; |
| while (pidList[i]) |
| i++; |
| if (--i >= 0) { |
| pid_t k; |
| int j; |
| for (j = 0; i > j; i--, j++) { |
| k = pidList[i]; |
| pidList[i] = pidList[j]; |
| pidList[j] = k; |
| } |
| } |
| return pidList; |
| } |