source: MondoRescue/branches/3.2/mindi-busybox/procps/pgrep.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * Mini pgrep/pkill implementation for busybox
 *
 * Copyright (C) 2007 Loic Grenie <loic.grenie@gmail.com>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//usage:#define pgrep_trivial_usage
//usage:       "[-flnovx] [-s SID|-P PPID|PATTERN]"
//usage:#define pgrep_full_usage "\n\n"
//usage:       "Display process(es) selected by regex PATTERN\n"
//usage:     "\n    -l  Show command name too"
//usage:     "\n    -f  Match against entire command line"
//usage:     "\n    -n  Show the newest process only"
//usage:     "\n    -o  Show the oldest process only"
//usage:     "\n    -v  Negate the match"
//usage:     "\n    -x  Match whole name (not substring)"
//usage:     "\n    -s  Match session ID (0 for current)"
//usage:     "\n    -P  Match parent process ID"
//usage:
//usage:#define pkill_trivial_usage
//usage:       "[-l|-SIGNAL] [-fnovx] [-s SID|-P PPID|PATTERN]"
//usage:#define pkill_full_usage "\n\n"
//usage:       "Send a signal to process(es) selected by regex PATTERN\n"
//usage:     "\n    -l  List all signals"
//usage:     "\n    -f  Match against entire command line"
//usage:     "\n    -n  Signal the newest process only"
//usage:     "\n    -o  Signal the oldest process only"
//usage:     "\n    -v  Negate the match"
//usage:     "\n    -x  Match whole name (not substring)"
//usage:     "\n    -s  Match session ID (0 for current)"
//usage:     "\n    -P  Match parent process ID"

#include "libbb.h"
#include "xregex.h"

/* Idea taken from kill.c */
#define pgrep (ENABLE_PGREP && applet_name[1] == 'g')
#define pkill (ENABLE_PKILL && applet_name[1] == 'k')

enum {
    /* "vlfxons:P:" */
    OPTBIT_V = 0, /* must be first, we need OPT_INVERT = 0/1 */
    OPTBIT_L,
    OPTBIT_F,
    OPTBIT_X,
    OPTBIT_O,
    OPTBIT_N,
    OPTBIT_S,
    OPTBIT_P,
};

#define OPT_INVERT  (opt & (1 << OPTBIT_V))
#define OPT_LIST    (opt & (1 << OPTBIT_L))
#define OPT_FULL    (opt & (1 << OPTBIT_F))
#define OPT_ANCHOR  (opt & (1 << OPTBIT_X))
#define OPT_FIRST   (opt & (1 << OPTBIT_O))
#define OPT_LAST    (opt & (1 << OPTBIT_N))
#define OPT_SID     (opt & (1 << OPTBIT_S))
#define OPT_PPID    (opt & (1 << OPTBIT_P))

static void act(unsigned pid, char *cmd, int signo)
{
    if (pgrep) {
        if (option_mask32 & (1 << OPTBIT_L)) /* OPT_LIST */
            printf("%d %s\n", pid, cmd);
        else
            printf("%d\n", pid);
    } else
        kill(pid, signo);
}

int pgrep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int pgrep_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned pid;
    int signo;
    unsigned opt;
    int scan_mask;
    int matched_pid;
    int sid2match, ppid2match;
    char *cmd_last;
    procps_status_t *proc;
    /* These are initialized to 0 */
    struct {
        regex_t re_buffer;
        regmatch_t re_match[1];
    } Z;
#define re_buffer (Z.re_buffer)
#define re_match  (Z.re_match )

    memset(&Z, 0, sizeof(Z));

    /* Parse -SIGNAL for pkill. Must be first option, if present */
    signo = SIGTERM;
    if (pkill && argv[1] && argv[1][0] == '-') {
        int temp = get_signum(argv[1]+1);
        if (temp != -1) {
            signo = temp;
            argv++;
        }
    }

    /* Parse remaining options */
    ppid2match = -1;
    sid2match = -1;
    opt_complementary = "s+:P+"; /* numeric opts */
    opt = getopt32(argv, "vlfxons:P:", &sid2match, &ppid2match);
    argv += optind;

    if (pkill && OPT_LIST) { /* -l: print the whole signal list */
        print_signames();
        return 0;
    }

    pid = getpid();
    if (sid2match == 0)
        sid2match = getsid(pid);

    scan_mask = PSSCAN_COMM | PSSCAN_ARGV0;
    if (OPT_FULL)
        scan_mask |= PSSCAN_ARGVN;

    /* One pattern is required, if no -s and no -P */
    if ((sid2match & ppid2match) < 0 && (!argv[0] || argv[1]))
        bb_show_usage();

    if (argv[0])
        xregcomp(&re_buffer, argv[0], REG_EXTENDED | REG_NOSUB);

    matched_pid = 0;
    cmd_last = NULL;
    proc = NULL;
    while ((proc = procps_scan(proc, scan_mask)) != NULL) {
        char *cmd;

        if (proc->pid == pid)
            continue;

        cmd = proc->argv0;
        if (!cmd) {
            cmd = proc->comm;
        } else {
            int i = proc->argv_len;
            while (--i >= 0) {
                if ((unsigned char)cmd[i] < ' ')
                    cmd[i] = ' ';
            }
        }

        if (ppid2match >= 0 && ppid2match != proc->ppid)
            continue;
        if (sid2match >= 0  && sid2match != proc->sid)
            continue;

        /* NB: OPT_INVERT is always 0 or 1 */
        if (!argv[0]
         || (regexec(&re_buffer, cmd, 1, re_match, 0) == 0 /* match found */
            && (!OPT_ANCHOR || (re_match[0].rm_so == 0 && re_match[0].rm_eo == (regoff_t)strlen(cmd)))
            ) ^ OPT_INVERT
        ) {
            matched_pid = proc->pid;
            if (OPT_LAST) {
                free(cmd_last);
                cmd_last = xstrdup(cmd);
                continue;
            }
            act(proc->pid, cmd, signo);
            if (OPT_FIRST)
                break;
        }
    }

    if (cmd_last) {
        act(matched_pid, cmd_last, signo);
        if (ENABLE_FEATURE_CLEAN_UP)
            free(cmd_last);
    }
    return matched_pid == 0; /* return 1 if no processes listed/signaled */
}