libbb/procps.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright 1998 by Albert Cahalan; all rights reserved.
   6  * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   9  */
  10
  11 #include <dirent.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <sys/param.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17
  18 #include "libbb.h"
  19
  20
  21 #define PROCPS_BUFSIZE 1024
  22
  23 static int read_to_buf(const char *filename, void *buf)
  24 {
  25         ssize_t ret;
  26         ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
  27         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
  28         return ret;
  29 }
  30
  31
  32 procps_status_t * procps_scan(int save_user_arg0)
  33 {
  34         static DIR *dir;
  35         static procps_status_t ret_status;
  36
  37         struct dirent *entry;
  38         char *name;
  39         int n;
  40         char status[32];
  41         char *status_tail;
  42         char buf[PROCPS_BUFSIZE];
  43         procps_status_t curstatus;
  44         int pid;
  45         long tasknice;
  46         struct stat sb;
  47
  48         if (!dir) {
  49                 dir = xopendir("/proc");
  50         }
  51         for (;;) {
  52                 entry = readdir(dir);
  53                 if (entry == NULL) {
  54                         closedir(dir);
  55                         dir = 0;
  56                         return 0;
  57                 }
  58                 name = entry->d_name;
  59                 if (!(*name >= '0' && *name <= '9'))
  60                         continue;
  61
  62                 memset(&curstatus, 0, sizeof(procps_status_t));
  63                 pid = atoi(name);
  64                 curstatus.pid = pid;
  65
  66                 status_tail = status + sprintf(status, "/proc/%d", pid);
  67                 if (stat(status, &sb))
  68                         continue;
  69                 bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
  70
  71                 /* see proc(5) for some details on this */
  72                 strcpy(status_tail, "/stat");
  73                 n = read_to_buf(status, buf);
  74                 if (n < 0)
  75                         continue;
  76                 name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
  77                 if (name == 0 || name[1] != ' ')
  78                         continue;
  79                 *name = 0;
  80                 sscanf(buf, "%*s (%15c", curstatus.short_cmd);
  81                 n = sscanf(name+2,
  82                 "%c %d "
  83                 "%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
  84                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
  85 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  86                 "%lu %lu "             /* utime, stime */
  87 #else
  88                 "%*s %*s "             /* utime, stime */
  89 #endif
  90                 "%*s %*s %*s "         /* cutime, cstime, priority */
  91                 "%ld "                 /* nice */
  92                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
  93                 "%*s "                 /* vsize */
  94                 "%ld",                 /* rss */
  95                 curstatus.state, &curstatus.ppid,
  96 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  97                 &curstatus.utime, &curstatus.stime,
  98 #endif
  99                 &tasknice,
 100                 &curstatus.rss);
 101 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 102                 if (n != 6)
 103 #else
 104                 if (n != 4)
 105 #endif
 106                         continue;
 107
 108                 if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
 109                         curstatus.state[1] = 'W';
 110                 else
 111                         curstatus.state[1] = ' ';
 112                 if (tasknice < 0)
 113                         curstatus.state[2] = '<';
 114                 else if (tasknice > 0)
 115                         curstatus.state[2] = 'N';
 116                 else
 117                         curstatus.state[2] = ' ';
 118
 119 #ifdef PAGE_SHIFT
 120                 curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
 121 #else
 122                 curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
 123 #endif
 124
 125                 if (save_user_arg0) {
 126                         strcpy(status_tail, "/cmdline");
 127                         n = read_to_buf(status, buf);
 128                         if (n > 0) {
 129                                 if (buf[n-1]=='\n')
 130                                         buf[--n] = 0;
 131                                 name = buf;
 132                                 while (n) {
 133                                         if (((unsigned char)*name) < ' ')
 134                                                 *name = ' ';
 135                                         name++;
 136                                         n--;
 137                                 }
 138                                 *name = 0;
 139                                 if (buf[0])
 140                                         curstatus.cmd = strdup(buf);
 141                                 /* if NULL it work true also */
 142                         }
 143                 }
 144                 return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
 145         }
 146 }