misc-utils/procs.c

   1 /*
   2  *  procs.c -- functions to parse the linux /proc filesystem.
   3  *  (c) 1994 salvatore valente <svalente@mit.edu>
   4  *
   5  *   this program is free software.  you can redistribute it and
   6  *   modify it under the terms of the gnu general public license.
   7  *   there is no warranty.
   8  *
   9  *   faith
  10  *   1.2
  11  *   1995/02/23 01:20:40
  12  *
  13  */
  14
  15 #define _POSIX_SOURCE 1
  16
  17 #include <sys/types.h>
  18 #include <sys/stat.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <dirent.h>
  23 #include <ctype.h>
  24 #include <unistd.h>
  25 #include "kill.h"
  26
  27 extern char *mybasename (char *);
  28 static char *parse_parens (char *buf);
  29
  30 int *
  31 get_pids (char *process_name, int get_all) {
  32     DIR *dir;
  33     struct dirent *ent;
  34     int status;
  35     char *dname, fname[100], *cp, buf[256];
  36     struct stat st;
  37     uid_t uid;
  38     FILE *fp;
  39     int pid, *pids, num_pids, pids_size;
  40
  41     dir = opendir ("/proc");
  42     if (! dir) {
  43         perror ("opendir /proc");
  44         return NULL;
  45     }
  46     uid = getuid ();
  47     pids = NULL;
  48     num_pids = pids_size = 0;
  49
  50     while ((ent = readdir (dir)) != NULL) {
  51         dname = ent->d_name;
  52         if (! isdigit (*dname)) continue;
  53         pid = atoi (dname);
  54         sprintf (fname, "/proc/%d/cmdline", pid);
  55         /* get the process owner */
  56         status = stat (fname, &st);
  57         if (status != 0) continue;
  58         if (! get_all && uid != st.st_uid) continue;
  59         /* get the command line */
  60         fp = fopen (fname, "r");
  61         if (! fp) continue;
  62         cp = fgets (buf, sizeof (buf), fp);
  63         fclose (fp);
  64         /* an empty command line means the process is swapped out */
  65         if (! cp || ! *cp) {
  66             /* get the process name from the statfile */
  67             sprintf (fname, "/proc/%d/stat", pid);
  68             fp = fopen (fname, "r");
  69             if (! fp) continue;
  70             cp = fgets (buf, sizeof (buf), fp);
  71             if (cp == NULL) continue;
  72             fclose (fp);
  73             cp = parse_parens (buf);
  74             if (cp == NULL) continue;
  75         }
  76         /* ok, we got the process name. */
  77         if (strcmp (process_name, mybasename (cp))) continue;
  78         while (pids_size < num_pids + 2) {
  79             pids_size += 5;
  80             pids = (int *) realloc (pids, sizeof (int) * pids_size);
  81         }
  82         pids[num_pids++] = pid;
  83         pids[num_pids] = -1;
  84     }
  85     closedir (dir);
  86     return (pids);
  87 }
  88
  89 /*
  90  *  parse_parens () -- return an index just past the first open paren in
  91  *      buf, and terminate the string at the matching close paren.
  92  */
  93 static char *parse_parens (char *buf)
  94 {
  95     char *cp, *ip;
  96     int depth;
  97
  98     cp = strchr (buf, '(');
  99     if (cp == NULL) return NULL;
 100     cp++;
 101     depth = 1;
 102     for (ip = cp; *ip; ip++) {
 103         if (*ip == '(')
 104             depth++;
 105         if (*ip == ')') {
 106             depth--;
 107             if (depth == 0) {
 108                 *ip = 0;
 109                 break;
 110             }
 111         }
 112     }
 113     return cp;
 114 }
 115
 116 char *mybasename (char *path)
 117 {
 118     char *cp;
 119
 120     cp = strrchr (path, '/');
 121     return (cp ? cp + 1 : path);
 122 }
 123