diff options
| -rw-r--r-- | include/usage.h | 2 | ||||
| -rw-r--r-- | libbb/find_pid_by_name.c | 29 | ||||
| -rw-r--r-- | procps/pidof.c | 33 |
3 files changed, 44 insertions, 20 deletions
diff --git a/include/usage.h b/include/usage.h index 2baa495ac..6d02c8bbf 100644 --- a/include/usage.h +++ b/include/usage.h @@ -2544,7 +2544,7 @@ USE_FEATURE_PIDOF_SINGLE( \ "\n -s Display only a single PID") \ USE_FEATURE_PIDOF_OMIT( \ - "\n -o Omit given pid") \ + "\n -o PID Omit given pid") \ USE_FEATURE_PIDOF_OMIT( \ "\n Use %PPID to omit the parent pid of pidof itself") #define pidof_example_usage \ diff --git a/libbb/find_pid_by_name.c b/libbb/find_pid_by_name.c index e98616940..13ccb545d 100644 --- a/libbb/find_pid_by_name.c +++ b/libbb/find_pid_by_name.c @@ -9,6 +9,35 @@ #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". +*/ + /* find_pid_by_name() * * Modified by Vladimir Oleynik for use with libbb/procps.c diff --git a/procps/pidof.c b/procps/pidof.c index 3541aeee0..01e587cbf 100644 --- a/procps/pidof.c +++ b/procps/pidof.c @@ -20,9 +20,9 @@ int pidof_main(int argc, char **argv); int pidof_main(int argc, char **argv) { unsigned first = 1; - unsigned fail = 1; unsigned opt; #if ENABLE_FEATURE_PIDOF_OMIT + char ppid_str[sizeof(int)*3 + 1]; llist_t *omits = NULL; /* list of pids to omit */ opt_complementary = "o::"; #endif @@ -35,14 +35,12 @@ int pidof_main(int argc, char **argv) #if ENABLE_FEATURE_PIDOF_OMIT /* fill omit list. */ { - char getppid_str[sizeof(int)*3 + 1]; - llist_t * omits_p = omits; + llist_t *omits_p = omits; while (omits_p) { /* are we asked to exclude the parent's process ID? */ - if (!strncmp(omits_p->data, "%PPID", 5)) { - llist_pop(&omits_p); - snprintf(getppid_str, sizeof(getppid_str), "%u", (unsigned)getppid()); - llist_add_to(&omits_p, getppid_str); + if (strcmp(omits_p->data, "%PPID") == 0) { + sprintf(ppid_str, "%u", (unsigned)getppid()); + omits_p->data = ppid_str; } omits_p = omits_p->link; } @@ -56,27 +54,24 @@ int pidof_main(int argc, char **argv) /* reverse the pidlist like GNU pidof does. */ pidList = pidlist_reverse(find_pid_by_name(argv[optind])); for (pl = pidList; *pl; pl++) { - SKIP_FEATURE_PIDOF_OMIT(const) unsigned omitted = 0; #if ENABLE_FEATURE_PIDOF_OMIT if (opt & OPT_OMIT) { llist_t *omits_p = omits; while (omits_p) { if (xatoul(omits_p->data) == *pl) { - omitted = 1; - break; - } else - omits_p = omits_p->link; + goto omitting; + } + omits_p = omits_p->link; } } #endif - if (!omitted) { - printf(" %u" + first, (unsigned)*pl); - first = 0; - } - fail = (!ENABLE_FEATURE_PIDOF_OMIT && omitted); - + printf(" %u" + first, (unsigned)*pl); + first = 0; if (ENABLE_FEATURE_PIDOF_SINGLE && (opt & OPT_SINGLE)) break; +#if ENABLE_FEATURE_PIDOF_OMIT + omitting: ; +#endif } free(pidList); optind++; @@ -87,5 +82,5 @@ int pidof_main(int argc, char **argv) if (ENABLE_FEATURE_CLEAN_UP) llist_free(omits, NULL); #endif - return fail ? EXIT_FAILURE : EXIT_SUCCESS; + return first; /* 1 (failure) - no processes found */ } |