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         struct dirent *entry;
  36         static procps_status_t ret_status;
  37         char *name;
  38         int n;
  39         char status[32];
  40         char *status_tail;
  41         char buf[PROCPS_BUFSIZE];
  42         procps_status_t curstatus;
  43         int pid;
  44         long tasknice;
  45         struct stat sb;
  46
  47         if (!dir) {
  48                 dir = xopendir("/proc");
  49         }
  50         for (;;) {
  51                 entry = readdir(dir);
  52                 if (entry == NULL) {
  53                         closedir(dir);
  54                         dir = 0;
  55                         return 0;
  56                 }
  57                 name = entry->d_name;
  58                 if (!(*name >= '0' && *name <= '9'))
  59                         continue;
  60
  61                 memset(&curstatus, 0, sizeof(procps_status_t));
  62                 pid = atoi(name);
  63                 curstatus.pid = pid;
  64
  65                 status_tail = status + sprintf(status, "/proc/%d", pid);
  66                 if (stat(status, &sb))
  67                         continue;
  68                 bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
  69
  70                 /* see proc(5) for some details on this */
  71                 strcpy(status_tail, "/stat");
  72                 n = read_to_buf(status, buf);
  73                 if (n < 0)
  74                         continue;
  75                 name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
  76                 if (name == 0 || name[1] != ' ')
  77                         continue;
  78                 *name = 0;
  79                 sscanf(buf, "%*s (%15c", curstatus.short_cmd);
  80                 n = sscanf(name+2,
  81                 "%c %d "
  82                 "%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
  83                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
  84 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  85                 "%lu %lu "             /* utime, stime */
  86 #else
  87                 "%*s %*s "             /* utime, stime */
  88 #endif
  89                 "%*s %*s %*s "         /* cutime, cstime, priority */
  90                 "%ld "                 /* nice */
  91                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
  92                 "%*s "                 /* vsize */
  93                 "%ld",                 /* rss */
  94                 curstatus.state, &curstatus.ppid,
  95 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  96                 &curstatus.utime, &curstatus.stime,
  97 #endif
  98                 &tasknice,
  99                 &curstatus.rss);
 100 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 101                 if (n != 6)
 102 #else
 103                 if (n != 4)
 104 #endif
 105                         continue;
 106
 107                 if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
 108                         curstatus.state[1] = 'W';
 109                 else
 110                         curstatus.state[1] = ' ';
 111                 if (tasknice < 0)
 112                         curstatus.state[2] = '<';
 113                 else if (tasknice > 0)
 114                         curstatus.state[2] = 'N';
 115                 else
 116                         curstatus.state[2] = ' ';
 117
 118 #ifdef PAGE_SHIFT
 119                 curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
 120 #else
 121                 curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
 122 #endif
 123
 124                 if (save_user_arg0) {
 125                         strcpy(status_tail, "/cmdline");
 126                         n = read_to_buf(status, buf);
 127                         if (n > 0) {
 128                                 if (buf[n-1]=='\n')
 129                                         buf[--n] = 0;
 130                                 name = buf;
 131                                 while (n) {
 132                                         if (((unsigned char)*name) < ' ')
 133                                                 *name = ' ';
 134                                         name++;
 135                                         n--;
 136                                 }
 137                                 *name = 0;
 138                                 if (buf[0])
 139                                         curstatus.cmd = strdup(buf);
 140                                 /* if NULL it work true also */
 141                         }
 142                 }
 143                 return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
 144         }
 145 }