#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
* Returns a list of all matching PIDs
* It is the caller's duty to free the returned pidlist.
*/
-pid_t* find_pid_by_name(const char* procName)
+pid_t* FAST_FUNC find_pid_by_name(const char *procName)
{
pid_t* pidList;
int i = 0;
- procps_status_t* p;
+ procps_status_t* p = NULL;
- pidList = xmalloc(sizeof(*pidList));
- while ((p = procps_scan(0)) != 0) {
- if (strncmp(p->short_cmd, procName, COMM_LEN-1) == 0) {
- pidList = xrealloc(pidList, sizeof(*pidList) * (i+2));
+ 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;
}
}
return pidList;
}
-pid_t *pidlist_reverse(pid_t *pidList)
+pid_t* FAST_FUNC pidlist_reverse(pid_t *pidList)
{
int i = 0;
while (pidList[i])