procps/pidof.c

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/*
* pidof.c - Utility for listing pids of running processes
*
* Copyright (C) 2013 Jaromir Capik <jcapik@redhat.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <stdio.h>
#include <getopt.h>
#include "c.h"
#include "fileutils.h"
#include "nls.h"
#include "xalloc.h"
#include "proc/readproc.h"
#include "proc/version.h" /* procps_version */
#define grow_size(x) (x = x * 5 / 4 + 1024)
#define safe_free(x) if (x) { free(x); x=NULL; }
struct el {
pid_t pid;
};
struct el *procs = NULL;
static int proc_count = 0;
struct el *omitted_procs = NULL;
static int omit_count = 0;
static char *program = NULL;
/* switch flags */
static int opt_single_shot = 0; /* -s */
static int opt_scripts_too = 0; /* -x */
static int opt_rootdir_check = 0; /* -c */
static char *pidof_root = NULL;
static int __attribute__ ((__noreturn__)) usage(int opt)
{
int err = (opt == '?');
FILE *fp = err ? stderr : stdout;
fputs(USAGE_HEADER, fp);
fprintf(fp, _(" %s [options] [program [...]]\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, fp);
fputs(_(" -s, --single-shot return one PID only\n"), fp);
fputs(_(" -c, --check-root omit processes with different root\n"), fp);
fputs(_(" -x scripts too\n"), fp);
fputs(_(" -o, --omit-pid <PID,...> omit processes with PID\n"), fp);
fputs(USAGE_SEPARATOR, fp);
fputs(USAGE_HELP, fp);
fputs(USAGE_VERSION, fp);
fprintf(fp, USAGE_MAN_TAIL("pidof(1)"));
exit(fp == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
static int is_omitted (pid_t pid)
{
int i;
for (i = 0; i < omit_count; i++) {
if (pid == omitted_procs[i].pid) return 1;
}
return 0;
}
static char *get_basename (char *filename)
{
char *pos;
char *result;
pos = result = filename;
while (*pos != '\0') {
if (*(pos++) == '/') result = pos;
}
return result;
}
static char *pid_link (pid_t pid, const char *base_name)
{
char link [PROCPATHLEN];
char *result;
int path_alloc_size;
int len;
snprintf(link, sizeof(link), "/proc/%d/%s", pid, base_name);
len = path_alloc_size = 0;
result = NULL;
do {
if (len == path_alloc_size) {
grow_size (path_alloc_size);
result = (char *) xrealloc (result, path_alloc_size);
}
if ((len = readlink(link, result, path_alloc_size - 1)) < 0) {
len = 0;
break;
}
} while (len == path_alloc_size);
result[len] = '\0';
return result;
}
static void select_procs (void)
{
PROCTAB *ptp;
proc_t task;
int match;
static int size = 0;
char *cmd_arg0, *cmd_arg0base;
char *cmd_arg1, *cmd_arg1base;
char *pos;
char *program_base;
char *root_link;
char *exe_link;
char *exe_link_base;
/* get the input base name */
program_base = get_basename(program);
ptp = openproc (PROC_FILLCOM | PROC_FILLSTAT);
exe_link = root_link = NULL;
memset(&task, 0, sizeof (task));
while(readproc(ptp, &task)) {
if (opt_rootdir_check) {
/* get the /proc/<pid>/root symlink value */
root_link = pid_link(task.XXXID, "root");
match = !strcmp(pidof_root, root_link);
safe_free(root_link);
if (!match) { /* root check failed */
memset (&task, 0, sizeof (task));
continue;
}
}
if (!is_omitted(task.XXXID) && task.cmdline) {
cmd_arg0 = *task.cmdline;
/* processes starting with '-' are login shells */
if (*cmd_arg0 == '-') {
cmd_arg0++;
}
/* get the argv0 base name */
cmd_arg0base = get_basename(cmd_arg0);
/* get the /proc/<pid>/exe symlink value */
exe_link = pid_link(task.XXXID, "exe");
/* get the exe_link base name */
exe_link_base = get_basename(exe_link);
match = 0;
if (!strcmp(program, cmd_arg0base) ||
!strcmp(program_base, cmd_arg0) ||
!strcmp(program, cmd_arg0) ||
!strcmp(program, exe_link_base) ||
!strcmp(program, exe_link))
{
match = 1;
} else if (opt_scripts_too && *(task.cmdline+1)) {
pos = cmd_arg1base = cmd_arg1 = *(task.cmdline+1);
/* get the arg1 base name */
while (*pos != '\0') {
if (*(pos++) == '/') cmd_arg1base = pos;
}
/* if script, then task.cmd = argv1, otherwise task.cmd = argv0 */
if (task.cmd &&
!strncmp(task.cmd, cmd_arg1base, strlen(task.cmd)) &&
(!strcmp(program, cmd_arg1base) ||
!strcmp(program_base, cmd_arg1) ||
!strcmp(program, cmd_arg1)))
{
match = 1;
}
}
safe_free(exe_link);
if (match) {
if (proc_count == size) {
grow_size(size);
procs = xrealloc(procs, size * (sizeof *procs));
}
if (procs) {
procs[proc_count++].pid = task.XXXID;
} else {
xerrx(EXIT_FAILURE, _("internal error"));
}
}
}
memset (&task, 0, sizeof (task));
}
closeproc (ptp);
}
static void add_to_omit_list (char *input_arg)
{
static int omit_size = 0;
char *omit_str;
char *endptr;
pid_t omit_pid;
omit_str = NULL;
omit_str = strtok(input_arg, ",;:");
while (omit_str) {
if (!strcmp(omit_str,"%PPID")) { /* keeping this %PPID garbage for backward compatibility only */
omit_pid = getppid(); /* ... as it can be replaced with $$ in common shells */
endptr = omit_str + sizeof("%PPID") - 1;
} else {
omit_pid = strtoul(omit_str, &endptr, 10);
}
if (*endptr == '\0') {
if (omit_count == omit_size) {
grow_size(omit_size);
omitted_procs = xrealloc(omitted_procs, omit_size * sizeof(*omitted_procs));
}
if (omitted_procs) {
omitted_procs[omit_count++].pid = omit_pid;
} else {
xerrx(EXIT_FAILURE, _("internal error"));
}
} else {
xwarnx(_("illegal omit pid value (%s)!\n"), omit_str);
}
omit_str = strtok(NULL, ",;:");
}
}
int main (int argc, char **argv)
{
int opt;
signed int i;
int found = 0;
int first_pid = 1;
const char *opts = "scnxmo:?Vh";
static const struct option longopts[] = {
{"check-root", no_argument, NULL, 'c'},
{"single-shot", no_argument, NULL, 's'},
{"omit-pid", required_argument, NULL, 'o'},
{"help", no_argument, NULL, 'h'},
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
#ifdef HAVE_PROGRAM_INVOCATION_NAME
program_invocation_name = program_invocation_short_name;
#endif
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
/* process command-line options */
while ((opt = getopt_long (argc, argv, opts, longopts, NULL)) != -1) {
switch (opt) {
case 's':
opt_single_shot = 1;
break;
case 'o':
add_to_omit_list (optarg);
break;
case 'x':
opt_scripts_too = 1;
break;
case 'c':
if (geteuid() == 0) {
opt_rootdir_check = 1;
pidof_root = pid_link(getpid(), "root");
}
break;
case 'V':
printf (PROCPS_NG_VERSION);
exit (EXIT_SUCCESS);
case 'h':
case '?':
usage (opt);
break;
/* compatibility-only switches */
case 'n': /* avoiding stat(2) on NFS volumes doesn't make any sense anymore ... */
/* ... as this reworked solution does not use stat(2) at all */
case 'm': /* omitting relatives with argv[0] & argv[1] matching the argv[0] & argv[1] ...*/
/* ... of explicitly omitted PIDs is too 'expensive' and as we don't know */
/* ... wheter it is still needed, we won't re-implement it unless ... */
/* ... somebody gives us a good reason to do so :) */
break;
}
}
/* main loop */
while (argc - optind) { /* for each program */
program = argv[optind++];
select_procs(); /* get the list of matching processes */
if (proc_count) {
found = 1;
for (i = proc_count - 1; i >= 0; i--) { /* and display their PIDs */
if (first_pid) {
first_pid = 0;
printf ("%ld", (long) procs[i].pid);
} else {
printf (" %ld", (long) procs[i].pid);
}
if (opt_single_shot) break;
}
proc_count = 0;
}
}
/* final line feed */
if (found) printf("\n");
/* some cleaning */
safe_free(procs);
safe_free(omitted_procs);
safe_free(pidof_root);
return !found;
}