1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
13 In Linux we have three ways to determine "process name":
14 1. /proc/PID/stat has "...(name)...", among other things. It's so-called "comm" field.
15 2. /proc/PID/cmdline's first NUL-terminated string. It's argv[0] from exec syscall.
16 3. /proc/PID/exe symlink. Points to the running executable file.
24 comm: first 15 chars of base name
25 (if executable is a symlink, then first 15 chars of symlink name are used)
26 cmdline: argv[0] from exec syscall
27 exe: points to executable (resolves symlink, unlike comm)
29 script (an executable with #!/path/to/interpreter):
30 comm: first 15 chars of script's base name (symlinks are not resolved)
31 cmdline: /path/to/interpreter (symlinks are not resolved)
32 (script name is in argv[1], args are pushed into argv[2] etc)
33 exe: points to interpreter's executable (symlinks are resolved)
35 If FEATURE_PREFER_APPLETS=y (and more so if FEATURE_SH_STANDALONE=y),
36 some commands started from busybox shell, xargs or find are started by
37 execXXX("/proc/self/exe", applet_name, params....)
38 and therefore comm field contains "exe".
41 static int comm_match(procps_status_t
*p
, const char *procName
)
46 if (strncmp(p
->comm
, procName
, 15) != 0)
47 return 0; /* comm does not match */
49 /* In Linux, if comm is 15 chars, it is truncated.
50 * (or maybe the name was exactly 15 chars, but there is
51 * no way to know that) */
52 if (p
->comm
[14] == '\0')
53 return 1; /* comm is not truncated - matches */
55 /* comm is truncated, but first 15 chars match.
56 * This can be crazily_long_script_name.sh!
57 * The telltale sign is basename(argv[1]) == procName */
62 argv1idx
= strlen(p
->argv0
) + 1;
63 if (argv1idx
>= p
->argv_len
)
65 argv1
= p
->argv0
+ argv1idx
;
67 if (strcmp(bb_basename(argv1
), procName
) != 0)
73 /* This finds the pid of the specified process.
74 * Currently, it's implemented by rummaging through
75 * the proc filesystem.
77 * Returns a list of all matching PIDs
78 * It is the caller's duty to free the returned pidlist.
80 * Modified by Vladimir Oleynik for use with libbb/procps.c
82 pid_t
* FAST_FUNC
find_pid_by_name(const char *procName
)
86 procps_status_t
* p
= NULL
;
88 pidList
= xzalloc(sizeof(*pidList
));
89 while ((p
= procps_scan(p
, PSSCAN_PID
|PSSCAN_COMM
|PSSCAN_ARGVN
|PSSCAN_EXE
))) {
90 if (comm_match(p
, procName
)
91 /* or we require argv0 to match (essential for matching reexeced /proc/self/exe)*/
92 || (p
->argv0
&& strcmp(bb_basename(p
->argv0
), procName
) == 0)
93 /* or we require /proc/PID/exe link to match */
94 || (p
->exe
&& strcmp(bb_basename(p
->exe
), procName
) == 0)
96 pidList
= xrealloc_vector(pidList
, 2, i
);
97 pidList
[i
++] = p
->pid
;
105 pid_t
* FAST_FUNC
pidlist_reverse(pid_t
*pidList
)
113 for (j
= 0; i
> j
; i
--, j
++) {
115 pidList
[i
] = pidList
[j
];