summaryrefslogtreecommitdiff
path: root/procps/pgrep.c
blob: 2ebcca1c01f4b546c1fd54aa64f722963eb90b73 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/* vi: set sw=4 ts=4: */
/*
 * Mini pgrep/pkill implementation for busybox
 *
 * Copyright (C) 2007 Loic Grenie <loic.grenie@gmail.com>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include <getopt.h>

#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 {
	/* "vlfxon" */
	PGREPOPTBIT_V = 0, /* must be first, we need OPT_INVERT = 0/1 */
	PGREPOPTBIT_L,
	PGREPOPTBIT_F,
	PGREPOPTBIT_X,
	PGREPOPTBIT_O,
	PGREPOPTBIT_N,
};

#define OPT_INVERT	(opt & (1 << PGREPOPTBIT_V))
#define OPT_LIST	(opt & (1 << PGREPOPTBIT_L))
#define OPT_FULL	(opt & (1 << PGREPOPTBIT_F))
#define OPT_ANCHOR	(opt & (1 << PGREPOPTBIT_X))
#define OPT_FIRST	(opt & (1 << PGREPOPTBIT_O))
#define OPT_LAST	(opt & (1 << PGREPOPTBIT_N))

static void act(unsigned pid, char *cmd, int signo, unsigned opt)
{
	if (pgrep) {
		if (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, char **argv)
{
	unsigned pid = getpid();
	int signo = SIGTERM;
	unsigned opt;
	int scan_mask = PSSCAN_COMM;
	char *first_arg;
	int first_arg_idx;
	int matched_pid;
	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));

	/* We must avoid interpreting -NUM (signal num) as an option */
	first_arg_idx = 1;
	while (1) {
		first_arg = argv[first_arg_idx];
		if (!first_arg)
			break;
		if (first_arg[0] != '-' || first_arg[1] < 'a' || first_arg[1] > 'z') {
			argv[first_arg_idx] = NULL;
			break;
		}
		first_arg_idx++;
	}
	opt = getopt32(argv, "vlfxon");
	argv[first_arg_idx] = first_arg;

	argv += optind;
	//argc -= optind; - unused anyway
	if (OPT_FULL)
		scan_mask |= PSSCAN_ARGVN;

	if (pkill) {
		if (OPT_LIST) { /* -l: print the whole signal list */
			print_signames();
			return 0;
		}
		if (first_arg && first_arg[0] == '-') {
			signo = get_signum(&first_arg[1]);
			if (signo < 0) /* || signo > MAX_SIGNUM ? */
				bb_error_msg_and_die("bad signal name '%s'", &first_arg[1]);
			argv++;
		}
	}

	/* One pattern is required */
	if (!argv[0] || argv[1])
		bb_show_usage();

	xregcomp(&re_buffer, argv[0], 0);
	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;
		/* NB: OPT_INVERT is always 0 or 1 */
		if ((regexec(&re_buffer, cmd, 1, re_match, 0) == 0 /* match found */
		     && (!OPT_ANCHOR || (re_match[0].rm_so == 0 && re_match[0].rm_eo == strlen(cmd)))) ^ OPT_INVERT
		) {
			matched_pid = proc->pid;
			if (OPT_LAST) {
				free(cmd_last);
				cmd_last = xstrdup(cmd);
				continue;
			}
			act(proc->pid, cmd, signo, opt);
			if (OPT_FIRST)
				break;
		}
	}
	if (cmd_last) {
		act(matched_pid, cmd_last, signo, opt);
		if (ENABLE_FEATURE_CLEAN_UP)
			free(cmd_last);
	}
	return matched_pid == 0; /* return 1 if no processes listed/signaled */
}