*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
- * Licensed under the GPL v2, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include <stdio.h>
-#include <ctype.h>
-#include <string.h>
-#include <stdlib.h>
#include "libbb.h"
-/* find_pid_by_name()
+/*
+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;
+ const char *argv1;
+
+ if (strncmp(p->comm, procName, 15) != 0)
+ return 0; /* comm does not match */
+
+ /* In Linux, if comm is 15 chars, it is truncated.
+ * (or maybe the name was exactly 15 chars, but there is
+ * no way to know that) */
+ if (p->comm[14] == '\0')
+ return 1; /* comm is not truncated - matches */
+
+ /* 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;
+ argv1 = p->argv0 + argv1idx;
+
+ if (strcmp(bb_basename(argv1), procName) != 0)
+ return 0;
+
+ return 1;
+}
+
+/* This finds the pid of the specified process.
+ * Currently, it's implemented by rummaging through
+ * the proc filesystem.
*
- * 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.
*
- * Returns a list of all matching PIDs
- * It is the caller's duty to free the returned pidlist.
+ * Modified by Vladimir Oleynik for use with libbb/procps.c
*/
-extern long* find_pid_by_name( const char* pidName)
+pid_t* FAST_FUNC find_pid_by_name(const char *procName)
{
- long* pidList;
- int i=0;
- procps_status_t * p;
-
- pidList = xmalloc(sizeof(long));
- while ((p = procps_scan(0)) != 0)
- {
- if (strncmp(p->short_cmd, pidName, COMM_LEN-1) == 0) {
- pidList=xrealloc( pidList, sizeof(long) * (i+2));
- pidList[i++]=p->pid;
+ 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|PSSCAN_EXE))) {
+ 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)
+ /* or we require /proc/PID/exe link to match */
+ || (p->exe && strcmp(bb_basename(p->exe), procName) == 0)
+ ) {
+ pidList = xrealloc_vector(pidList, 2, i);
+ pidList[i++] = p->pid;
}
}
- pidList[i] = i==0 ? -1 : 0;
+ pidList[i] = 0;
return pidList;
}
-extern long *pidlist_reverse(long *pidList)
+pid_t* FAST_FUNC pidlist_reverse(pid_t *pidList)
{
- int i=0;
- while (pidList[i] > 0 && i++);
- if ( i-- > 0) {
- long k;
+ 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];
}
return pidList;
}
-
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
projects / platform / upstream / busybox.git / blobdiff