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         int fd;
  26         ssize_t ret;
  27
  28         fd = open(filename, O_RDONLY);
  29         if(fd < 0)
  30                 return -1;
  31         ret = read(fd, buf, PROCPS_BUFSIZE);
  32         close(fd);
  33         return ret;
  34 }
  35
  36
  37 procps_status_t * procps_scan(int save_user_arg0)
  38 {
  39         static DIR *dir;
  40         struct dirent *entry;
  41         static procps_status_t ret_status;
  42         char *name;
  43         int n;
  44         char status[32];
  45         char *status_tail;
  46         char buf[PROCPS_BUFSIZE];
  47         procps_status_t curstatus;
  48         int pid;
  49         long tasknice;
  50         struct stat sb;
  51
  52         if (!dir) {
  53                 dir = bb_xopendir("/proc");
  54         }
  55         for(;;) {
  56                 if((entry = readdir(dir)) == NULL) {
  57                         closedir(dir);
  58                         dir = 0;
  59                         return 0;
  60                 }
  61                 name = entry->d_name;
  62                 if (!(*name >= '0' && *name <= '9'))
  63                         continue;
  64
  65                 memset(&curstatus, 0, sizeof(procps_status_t));
  66                 pid = atoi(name);
  67                 curstatus.pid = pid;
  68
  69                 status_tail = status + sprintf(status, "/proc/%d", pid);
  70                 if(stat(status, &sb))
  71                         continue;
  72                 bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
  73
  74                 /* see proc(5) for some details on this */
  75                 strcpy(status_tail, "/stat");
  76                 n = read_to_buf(status, buf);
  77                 if(n < 0)
  78                         continue;
  79                 name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
  80                 if(name == 0 || name[1] != ' ')
  81                         continue;
  82                 *name = 0;
  83                 sscanf(buf, "%*s (%15c", curstatus.short_cmd);
  84                 n = sscanf(name+2,
  85                 "%c %d "
  86                 "%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
  87                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
  88 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  89                 "%lu %lu "             /* utime, stime */
  90 #else
  91                 "%*s %*s "             /* utime, stime */
  92 #endif
  93                 "%*s %*s %*s "         /* cutime, cstime, priority */
  94                 "%ld "                 /* nice */
  95                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
  96                 "%*s "                 /* vsize */
  97                 "%ld",                 /* rss */
  98                 curstatus.state, &curstatus.ppid,
  99 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 100                 &curstatus.utime, &curstatus.stime,
 101 #endif
 102                 &tasknice,
 103                 &curstatus.rss);
 104 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 105                 if(n != 6)
 106 #else
 107                 if(n != 4)
 108 #endif
 109                         continue;
 110
 111                 if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
 112                         curstatus.state[1] = 'W';
 113                 else
 114                         curstatus.state[1] = ' ';
 115                 if (tasknice < 0)
 116                         curstatus.state[2] = '<';
 117                 else if (tasknice > 0)
 118                         curstatus.state[2] = 'N';
 119                 else
 120                         curstatus.state[2] = ' ';
 121
 122 #ifdef PAGE_SHIFT
 123                 curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
 124 #else
 125                 curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
 126 #endif
 127
 128                 if(save_user_arg0) {
 129                         strcpy(status_tail, "/cmdline");
 130                         n = read_to_buf(status, buf);
 131                         if(n > 0) {
 132                                 if(buf[n-1]=='\n')
 133                                         buf[--n] = 0;
 134                                 name = buf;
 135                                 while(n) {
 136                                         if(((unsigned char)*name) < ' ')
 137                                                 *name = ' ';
 138                                         name++;
 139                                         n--;
 140                                 }
 141                                 *name = 0;
 142                                 if(buf[0])
 143                                         curstatus.cmd = strdup(buf);
 144                                 /* if NULL it work true also */
 145                         }
 146                 }
 147                 return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
 148         }
 149 }