source: MondoRescue/branches/2.2.2/mindi-busybox/libbb/procps.c@ 1247

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright 1998 by Albert Cahalan; all rights reserved.
 * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <dirent.h>
#include <string.h>
#include <stdlib.h>
#include <sys/param.h>
#include <unistd.h>
#include <fcntl.h>

#include "libbb.h"


#define PROCPS_BUFSIZE 1024

static int read_to_buf(const char *filename, void *buf)
{
    int fd;
    ssize_t ret;

    fd = open(filename, O_RDONLY);
    if(fd < 0)
        return -1;
    ret = read(fd, buf, PROCPS_BUFSIZE-1);
    ((char *)buf)[ret > 0 ? ret : 0] = 0;
    close(fd);
    return ret;
}


procps_status_t * procps_scan(int save_user_arg0)
{
    static DIR *dir;
    struct dirent *entry;
    static procps_status_t ret_status;
    char *name;
    int n;
    char status[32];
    char *status_tail;
    char buf[PROCPS_BUFSIZE];
    procps_status_t curstatus;
    int pid;
    long tasknice;
    struct stat sb;

    if (!dir) {
        dir = bb_xopendir("/proc");
    }
    for(;;) {
        if((entry = readdir(dir)) == NULL) {
            closedir(dir);
            dir = 0;
            return 0;
        }
        name = entry->d_name;
        if (!(*name >= '0' && *name <= '9'))
            continue;

        memset(&curstatus, 0, sizeof(procps_status_t));
        pid = atoi(name);
        curstatus.pid = pid;

        status_tail = status + sprintf(status, "/proc/%d", pid);
        if(stat(status, &sb))
            continue;
        bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));

        /* see proc(5) for some details on this */
        strcpy(status_tail, "/stat");
        n = read_to_buf(status, buf);
        if(n < 0)
            continue;
        name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
        if(name == 0 || name[1] != ' ')
            continue;
        *name = 0;
        sscanf(buf, "%*s (%15c", curstatus.short_cmd);
        n = sscanf(name+2,
        "%c %d "
        "%*s %*s %*s %*s "     /* pgrp, session, tty, tpgid */
        "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
        "%lu %lu "             /* utime, stime */
#else
        "%*s %*s "             /* utime, stime */
#endif
        "%*s %*s %*s "         /* cutime, cstime, priority */
        "%ld "                 /* nice */
        "%*s %*s %*s "         /* timeout, it_real_value, start_time */
        "%*s "                 /* vsize */
        "%ld",                 /* rss */
        curstatus.state, &curstatus.ppid,
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
        &curstatus.utime, &curstatus.stime,
#endif
        &tasknice,
        &curstatus.rss);
#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
        if(n != 6)
#else
        if(n != 4)
#endif
            continue;

        if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
            curstatus.state[1] = 'W';
        else
            curstatus.state[1] = ' ';
        if (tasknice < 0)
            curstatus.state[2] = '<';
        else if (tasknice > 0)
            curstatus.state[2] = 'N';
        else
            curstatus.state[2] = ' ';

#ifdef PAGE_SHIFT
        curstatus.rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
#else
        curstatus.rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
#endif

        if(save_user_arg0) {
            strcpy(status_tail, "/cmdline");
            n = read_to_buf(status, buf);
            if(n > 0) {
                if(buf[n-1]=='\n')
                    buf[--n] = 0;
                name = buf;
                while(n) {
                    if(((unsigned char)*name) < ' ')
                        *name = ' ';
                    name++;
                    n--;
                }
                *name = 0;
                if(buf[0])
                    curstatus.cmd = strdup(buf);
                /* if NULL it work true also */
            }
        }
        return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
    }
}