busybox/coreutils/dd.c

206 lines
4.1 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini dd implementation for busybox
*
*
* Copyright (C) 2000,2001 Matt Kraai
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h> // For FEATURE_DD_SIGNAL_HANDLING
#include "busybox.h"
static const struct suffix_mult dd_suffixes[] = {
{ "c", 1 },
{ "w", 2 },
{ "b", 512 },
{ "kD", 1000 },
{ "k", 1024 },
{ "MD", 1000000 },
{ "M", 1048576 },
{ "GD", 1000000000 },
{ "G", 1073741824 },
{ NULL, 0 }
};
static size_t out_full;
static size_t out_part;
static size_t in_full;
static size_t in_part;
static void dd_output_status(int cur_signal)
{
fprintf(stderr, "%ld+%ld records in\n%ld+%ld records out\n",
(long)in_full, (long)in_part,
(long)out_full, (long)out_part);
}
int dd_main(int argc, char **argv)
{
size_t count = -1;
size_t bs = 512;
ssize_t n;
off_t seek = 0;
off_t skip = 0;
int sync_flag = FALSE;
int noerror = FALSE;
int trunc_flag = TRUE;
int oflag;
int ifd;
int ofd;
int i;
const char *infile = NULL;
const char *outfile = NULL;
char *buf;
if (ENABLE_FEATURE_DD_SIGNAL_HANDLING)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = dd_output_status;
sa.sa_flags = SA_RESTART;
sigemptyset(&sa.sa_mask);
sigaction(SIGUSR1, &sa, 0);
}
for (i = 1; i < argc; i++) {
if (strncmp("bs=", argv[i], 3) == 0)
bs = bb_xparse_number(argv[i]+3, dd_suffixes);
else if (strncmp("count=", argv[i], 6) == 0)
count = bb_xparse_number(argv[i]+6, dd_suffixes);
else if (strncmp("seek=", argv[i], 5) == 0)
seek = bb_xparse_number(argv[i]+5, dd_suffixes);
else if (strncmp("skip=", argv[i], 5) == 0)
skip = bb_xparse_number(argv[i]+5, dd_suffixes);
else if (strncmp("if=", argv[i], 3) == 0)
infile = argv[i]+3;
else if (strncmp("of=", argv[i], 3) == 0)
outfile = argv[i]+3;
else if (strncmp("conv=", argv[i], 5) == 0) {
buf = argv[i]+5;
while (1) {
if (strncmp("notrunc", buf, 7) == 0) {
trunc_flag = FALSE;
buf += 7;
} else if (strncmp("sync", buf, 4) == 0) {
sync_flag = TRUE;
buf += 4;
} else if (strncmp("noerror", buf, 7) == 0) {
noerror = TRUE;
buf += 7;
} else {
bb_error_msg_and_die("invalid conversion `%s'", argv[i]+5);
}
if (buf[0] == '\0')
break;
if (buf[0] == ',')
buf++;
}
} else
bb_show_usage();
}
buf = xmalloc(bs);
if (infile != NULL) {
ifd = bb_xopen(infile, O_RDONLY);
} else {
ifd = STDIN_FILENO;
infile = bb_msg_standard_input;
}
if (outfile != NULL) {
oflag = O_WRONLY | O_CREAT;
if (!seek && trunc_flag) {
oflag |= O_TRUNC;
}
ofd = bb_xopen3(outfile, oflag, 0666);
if (seek && trunc_flag) {
if (ftruncate(ofd, seek * bs) < 0) {
struct stat st;
if (fstat (ofd, &st) < 0 || S_ISREG (st.st_mode) ||
S_ISDIR (st.st_mode)) {
bb_perror_msg_and_die("%s", outfile);
}
}
}
} else {
ofd = STDOUT_FILENO;
outfile = bb_msg_standard_output;
}
if (skip) {
if (lseek(ifd, skip * bs, SEEK_CUR) < 0) {
bb_perror_msg_and_die("%s", infile);
}
}
if (seek) {
if (lseek(ofd, seek * bs, SEEK_CUR) < 0) {
bb_perror_msg_and_die("%s", outfile);
}
}
while (in_full + in_part != count) {
if (noerror) {
/* Pre-zero the buffer when doing the noerror thing */
memset(buf, '\0', bs);
}
n = safe_read(ifd, buf, bs);
if (n < 0) {
if (noerror) {
n = bs;
bb_perror_msg("%s", infile);
} else {
bb_perror_msg_and_die("%s", infile);
}
}
if (n == 0) {
break;
}
if ((size_t)n == bs) {
in_full++;
} else {
in_part++;
}
if (sync_flag) {
memset(buf + n, '\0', bs - n);
n = bs;
}
n = bb_full_write(ofd, buf, n);
if (n < 0) {
bb_perror_msg_and_die("%s", outfile);
}
if ((size_t)n == bs) {
out_full++;
} else {
out_part++;
}
}
if (close (ifd) < 0) {
bb_perror_msg_and_die("%s", infile);
}
if (close (ofd) < 0) {
bb_perror_msg_and_die("%s", outfile);
}
dd_output_status(0);
return EXIT_SUCCESS;
}