hush/procps/smemcap.c

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/*
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 "bb_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;
}