aboutsummaryrefslogtreecommitdiff
path: root/ps.c
blob: 1f6175318681f8e0df74a26185b1f300df2bc99b (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
146
147
148
149
150
151
152
/*
 * Mini ps implementation for busybox
 *
 *
 * Copyright (C) 1999 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "internal.h"
#include <unistd.h>
#include <dirent.h>
#include <stdio.h>
#include <fcntl.h>
#include <ctype.h>


typedef struct proc_s {
    char
    	cmd[16];	/* basename of executable file in call to exec(2) */
    int
        ruid, rgid,     /* real only (sorry) */
    	pid,		/* process id */
    	ppid;		/* pid of parent process */
    char
    	state;		/* single-char code for process state (S=sleeping) */
} proc_t;



static int file2str(char *filename, char *ret, int cap) 
{
    int fd, num_read;

    if ( (fd       = open(filename, O_RDONLY, 0)) == -1 ) return -1;
    if ( (num_read = read(fd, ret, cap - 1))      <= 0 ) return -1;
    ret[num_read] = 0;
    close(fd);
    return num_read;
}


static void parse_proc_status(char* S, proc_t* P) 
{
    char* tmp;
    memset(P->cmd, 0, sizeof P->cmd);
    sscanf (S, "Name:\t%15c", P->cmd);
    tmp = strchr(P->cmd,'\n');
    if (tmp)
	*tmp='\0';
    tmp = strstr (S,"State");
    sscanf (tmp, "State:\t%c", &P->state);

    tmp = strstr (S,"Pid:");
    if(tmp) sscanf (tmp,
        "Pid:\t%d\n"
        "PPid:\t%d\n",
        &P->pid,
        &P->ppid
    );
    else fprintf(stderr, "Internal error!\n");

    /* For busybox, ignoring effective, saved, etc */
    tmp = strstr (S,"Uid:");
    if(tmp) sscanf (tmp,
        "Uid:\t%d", &P->ruid);
    else fprintf(stderr, "Internal error!\n");

    tmp = strstr (S,"Gid:");
    if(tmp) sscanf (tmp,
        "Gid:\t%d", &P->rgid);
    else fprintf(stderr, "Internal error!\n");

}


extern int ps_main(int argc, char **argv)
{
    proc_t p;
    DIR *dir;
    FILE *file;
    struct dirent *entry;
    char path[32], sbuf[512];
    char uidName[10]="";
    char groupName[10]="";
    int i, c;

    if ( argc>1 && **(argv+1) == '-' ) {
	usage ("ps\n\nReport process status\n\nThis version of ps accepts no options.\n");
    }
    
    dir = opendir("/proc");
    if (!dir) {
	perror("Can't open /proc");
	exit(FALSE);
    }

    fprintf(stdout, "%5s  %-8s %-3s %5s %s\n", "PID", "Uid", "Gid", "State", "Command");
    while ((entry = readdir(dir)) != NULL) {
	uidName[0]='\0';
	groupName[0]='\0';
		
	if (! isdigit(*entry->d_name))
	    continue;
	sprintf(path, "/proc/%s/status", entry->d_name);
	if ((file2str(path, sbuf, sizeof sbuf)) != -1 ) {
	    parse_proc_status(sbuf, &p);
	}

	/* Make some adjustments as needed */
	my_getpwuid( uidName, p.ruid);
	my_getgrgid( groupName, p.rgid);
	if (*uidName == '\0')
	    sprintf( uidName, "%d", p.ruid);
	if (*groupName == '\0')
	    sprintf( groupName, "%d", p.rgid);

	fprintf(stdout, "%5d %-8s %-8s %c ", p.pid, uidName, groupName, p.state);
	sprintf(path, "/proc/%s/cmdline", entry->d_name);
	file = fopen(path, "r");
	if (file == NULL) {
	    perror(path);
	    exit(FALSE);
	}
	i=0;
	while (((c = getc(file)) != EOF) && (i < 53)) {
	    i++;
	    if (c == '\0')
		c = ' ';
	    putc(c, stdout);
	}
	if (i==0)
	    fprintf(stdout, "%s", p.cmd);
	fprintf(stdout, "\n");
    }
    closedir(dir);
    exit(TRUE);
}