mirror of
https://github.com/topjohnwu/ndk-busybox.git
synced 2024-12-01 07:30:24 +00:00
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
/* 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)
|
|
/* TODO: 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;
|
|
}
|