aboutsummaryrefslogtreecommitdiff
path: root/libbb/procps.c
blob: eba90705cc8b7bfbb4448caed79273f28f2f4ba1 (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
139
140
141
142
143
144
145
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright 1998 by Albert Cahalan; all rights reserved.
 * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <dirent.h>
#include <string.h>
#include <stdlib.h>
#include <sys/param.h>
#include <unistd.h>
#include <fcntl.h>

#include "libbb.h"


#define PROCPS_BUFSIZE 1024

static int read_to_buf(const char *filename, void *buf)
{
	ssize_t ret;
	ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
	((char *)buf)[ret > 0 ? ret : 0] = '\0';
	return ret;
}


procps_status_t * procps_scan(int save_user_arg0)
{
	static DIR *dir;
	struct dirent *entry;
	static procps_status_t ret_status;
	char *name;
	int n;
	char status[32];
	char *status_tail;
	char buf[PROCPS_BUFSIZE];
	procps_status_t curstatus;
	int pid;
	long tasknice;
	struct stat sb;

	if (!dir) {
		dir = xopendir("/proc");
	}
	for (;;) {
		entry = readdir(dir);
		if (entry == NULL) {
			closedir(dir);
			dir = 0;
			return 0;
		}
		name = entry->d_name;
		if (!(*name >= '0' && *name <= '9'))
			continue;

		memset(&curstatus, 0, sizeof(procps_status_t));
		pid = atoi(name);
		curstatus.pid = pid;

		status_tail = status + sprintf(status, "/proc/%d", pid);
		if (stat(status, &sb))
			continue;
		bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));

		/* see proc(5) for some details on this */
		strcpy(status_tail, "/stat");
		n = read_to_buf(status, buf);
		if (n < 0)
			continue;
		name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
		if (name == 0 || name[1] != ' ')
			continue;
		*name = 0;
		sscanf(buf, "%*s (%15c", curstatus.short_cmd);
		n = sscanf(name+2,
		"%c %d "
		"%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
		"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
		"%lu %lu "             /* utime, stime */
#else
		"%*s %*s "             /* utime, stime */
#endif
		"%*s %*s %*s "         /* cutime, cstime, priority */
		"%ld "                 /* nice */
		"%*s %*s %*s "         /* timeout, it_real_value, start_time */
		"%*s "                 /* vsize */
		"%ld",                 /* rss */
		curstatus.state, &curstatus.ppid,
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
		&curstatus.utime, &curstatus.stime,
#endif
		&tasknice,
		&curstatus.rss);
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
		if (n != 6)
#else
		if (n != 4)
#endif
			continue;

		if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
			curstatus.state[1] = 'W';
		else
			curstatus.state[1] = ' ';
		if (tasknice < 0)
			curstatus.state[2] = '<';
		else if (tasknice > 0)
			curstatus.state[2] = 'N';
		else
			curstatus.state[2] = ' ';

#ifdef PAGE_SHIFT
		curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
#else
		curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
#endif

		if (save_user_arg0) {
			strcpy(status_tail, "/cmdline");
			n = read_to_buf(status, buf);
			if (n > 0) {
				if (buf[n-1]=='\n')
					buf[--n] = 0;
				name = buf;
				while (n) {
					if (((unsigned char)*name) < ' ')
						*name = ' ';
					name++;
					n--;
				}
				*name = 0;
				if (buf[0])
					curstatus.cmd = strdup(buf);
				/* if NULL it work true also */
			}
		}
		return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
	}
}