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-1);
  32         ((char *)buf)[ret > 0 ? ret : 0] = 0;
  33         close(fd);
  34         return ret;
  35 }
  36
  37
  38 procps_status_t * procps_scan(int save_user_arg0)
  39 {
  40         static DIR *dir;
  41         struct dirent *entry;
  42         static procps_status_t ret_status;
  43         char *name;
  44         int n;
  45         char status[32];
  46         char *status_tail;
  47         char buf[PROCPS_BUFSIZE];
  48         procps_status_t curstatus;
  49         int pid;
  50         long tasknice;
  51         struct stat sb;
  52
  53         if (!dir) {
  54                 dir = xopendir("/proc");
  55         }
  56         for (;;) {
  57                 entry = readdir(dir);
  58                 if (entry == NULL) {
  59                         closedir(dir);
  60                         dir = 0;
  61                         return 0;
  62                 }
  63                 name = entry->d_name;
  64                 if (!(*name >= '0' && *name <= '9'))
  65                         continue;
  66
  67                 memset(&curstatus, 0, sizeof(procps_status_t));
  68                 pid = atoi(name);
  69                 curstatus.pid = pid;
  70
  71                 status_tail = status + sprintf(status, "/proc/%d", pid);
  72                 if (stat(status, &sb))
  73                         continue;
  74                 bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
  75
  76                 /* see proc(5) for some details on this */
  77                 strcpy(status_tail, "/stat");
  78                 n = read_to_buf(status, buf);
  79                 if (n < 0)
  80                         continue;
  81                 name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
  82                 if (name == 0 || name[1] != ' ')
  83                         continue;
  84                 *name = 0;
  85                 sscanf(buf, "%*s (%15c", curstatus.short_cmd);
  86                 n = sscanf(name+2,
  87                 "%c %d "
  88                 "%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
  89                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
  90 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  91                 "%lu %lu "             /* utime, stime */
  92 #else
  93                 "%*s %*s "             /* utime, stime */
  94 #endif
  95                 "%*s %*s %*s "         /* cutime, cstime, priority */
  96                 "%ld "                 /* nice */
  97                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
  98                 "%*s "                 /* vsize */
  99                 "%ld",                 /* rss */
 100                 curstatus.state, &curstatus.ppid,
 101 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 102                 &curstatus.utime, &curstatus.stime,
 103 #endif
 104                 &tasknice,
 105                 &curstatus.rss);
 106 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 107                 if (n != 6)
 108 #else
 109                 if (n != 4)
 110 #endif
 111                         continue;
 112
 113                 if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
 114                         curstatus.state[1] = 'W';
 115                 else
 116                         curstatus.state[1] = ' ';
 117                 if (tasknice < 0)
 118                         curstatus.state[2] = '<';
 119                 else if (tasknice > 0)
 120                         curstatus.state[2] = 'N';
 121                 else
 122                         curstatus.state[2] = ' ';
 123
 124 #ifdef PAGE_SHIFT
 125                 curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
 126 #else
 127                 curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
 128 #endif
 129
 130                 if (save_user_arg0) {
 131                         strcpy(status_tail, "/cmdline");
 132                         n = read_to_buf(status, buf);
 133                         if (n > 0) {
 134                                 if (buf[n-1]=='\n')
 135                                         buf[--n] = 0;
 136                                 name = buf;
 137                                 while (n) {
 138                                         if (((unsigned char)*name) < ' ')
 139                                                 *name = ' ';
 140                                         name++;
 141                                         n--;
 142                                 }
 143                                 *name = 0;
 144                                 if (buf[0])
 145                                         curstatus.cmd = strdup(buf);
 146                                 /* if NULL it work true also */
 147                         }
 148                 }
 149                 return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
 150         }
 151 }