source: MondoRescue/branches/2.2.9/mindi-busybox/procps/smemcap.c@ 3320

/*
 smemcap - a tool for meaningful memory reporting

 Copyright 2008-2009 Matt Mackall <mpm@selenic.com>

 This software may be used and distributed according to the terms of
 the GNU General Public License version 2 or later, incorporated
 herein by reference.
*/

//applet:IF_SMEMCAP(APPLET(smemcap, _BB_DIR_USR_BIN, _BB_SUID_DROP))

//kbuild:lib-$(CONFIG_SMEMCAP) += smemcap.o

//config:config SMEMCAP
//config:   bool "smemcap"
//config:   default y
//config:   help
//config:     smemcap is a tool for capturing process data for smem,
//config:     a memory usage statistic tool.

#include "libbb.h"
#include "archive.h"

struct fileblock {
    struct fileblock *next;
    char data[TAR_BLOCK_SIZE];
};

static void writeheader(const char *path, struct stat *sb, int type)
{
    struct tar_header_t header;
    int i, sum;

    memset(&header, 0, TAR_BLOCK_SIZE);
    strcpy(header.name, path);
    sprintf(header.mode, "%o", sb->st_mode & 0777);
    /* careful to not overflow fields! */
    sprintf(header.uid, "%o", sb->st_uid & 07777777);
    sprintf(header.gid, "%o", sb->st_gid & 07777777);
    sprintf(header.size, "%o", (unsigned)sb->st_size);
    sprintf(header.mtime, "%llo", sb->st_mtime & 077777777777LL);
    header.typeflag = type;
    strcpy(header.magic, "ustar  "); /* like GNU tar */

    /* Calculate and store the checksum (the sum of all of the bytes of
     * the header). The checksum field must be filled with blanks for the
     * calculation. The checksum field is formatted differently from the
     * other fields: it has 6 digits, a NUL, then a space -- rather than
     * digits, followed by a NUL like the other fields... */
    header.chksum[7] = ' ';
    sum = ' ' * 7;
    for (i = 0; i < TAR_BLOCK_SIZE; i++)
        sum += ((unsigned char*)&header)[i];
    sprintf(header.chksum, "%06o", sum);

    xwrite(STDOUT_FILENO, &header, TAR_BLOCK_SIZE);
}

static void archivefile(const char *path)
{
    struct fileblock *start, *cur;
    struct fileblock **prev = &start;
    int fd, r;
    unsigned size = 0;
    struct stat s;

    /* buffer the file */
    fd = xopen(path, O_RDONLY);
    do {
        cur = xzalloc(sizeof(*cur));
        *prev = cur;
        prev = &cur->next;
        r = full_read(fd, cur->data, TAR_BLOCK_SIZE);
        if (r > 0)
            size += r;
    } while (r == TAR_BLOCK_SIZE);

    /* write archive header */
    fstat(fd, &s);
    close(fd);
    s.st_size = size;
    writeheader(path, &s, '0');

    /* dump file contents */
    for (cur = start; (int)size > 0; size -= TAR_BLOCK_SIZE) {
        xwrite(STDOUT_FILENO, cur->data, TAR_BLOCK_SIZE);
        start = cur;
        cur = cur->next;
        free(start);
    }
}

static void archivejoin(const char *sub, const char *name)
{
    char path[sizeof(long long)*3 + sizeof("/cmdline")];
    sprintf(path, "%s/%s", sub, name);
    archivefile(path);
}

//usage:#define smemcap_trivial_usage ">SMEMDATA.TAR"
//usage:#define smemcap_full_usage "\n\n"
//usage:       "Collect memory usage data in /proc and write it to stdout"

int smemcap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int smemcap_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
{
    DIR *d;
    struct dirent *de;

    xchdir("/proc");
    d = xopendir(".");

    archivefile("meminfo");
    archivefile("version");
    while ((de = readdir(d)) != NULL) {
        if (isdigit(de->d_name[0])) {
            struct stat s;
            memset(&s, 0, sizeof(s));
            s.st_mode = 0555;
            writeheader(de->d_name, &s, '5');
            archivejoin(de->d_name, "smaps");
            archivejoin(de->d_name, "cmdline");
            archivejoin(de->d_name, "stat");
        }
    }

    if (ENABLE_FEATURE_CLEAN_UP)
        closedir(d);

    return EXIT_SUCCESS;
}