hush/dd.c
2001-07-31 21:02:19 +00:00

155 lines
3.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini dd implementation for busybox
*
*
* Copyright (C) 2000 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#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 }
};
int dd_main(int argc, char **argv)
{
int i, ifd, ofd, oflag, sync_flag = FALSE, trunc = TRUE;
size_t in_full = 0, in_part = 0, out_full = 0, out_part = 0;
size_t bs = 512, count = -1;
ssize_t n;
off_t seek = 0, skip = 0;
char *infile = NULL, *outfile = NULL, *buf;
for (i = 1; i < argc; i++) {
if (strncmp("bs=", argv[i], 3) == 0)
bs = parse_number(argv[i]+3, dd_suffixes);
else if (strncmp("count=", argv[i], 6) == 0)
count = parse_number(argv[i]+6, dd_suffixes);
else if (strncmp("seek=", argv[i], 5) == 0)
seek = parse_number(argv[i]+5, dd_suffixes);
else if (strncmp("skip=", argv[i], 5) == 0)
skip = parse_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 = FALSE;
buf += 7;
} else if (strncmp("sync", buf, 4) == 0) {
sync_flag = TRUE;
buf += 4;
} else {
error_msg_and_die("invalid conversion `%s'", argv[i]+5);
}
if (buf[0] == '\0')
break;
if (buf[0] == ',')
buf++;
}
} else
show_usage();
}
buf = xmalloc(bs);
if (infile != NULL) {
if ((ifd = open(infile, O_RDONLY)) < 0)
perror_msg_and_die("%s", infile);
} else {
ifd = STDIN_FILENO;
infile = "standard input";
}
if (outfile != NULL) {
oflag = O_WRONLY | O_CREAT;
if (!seek && trunc)
oflag |= O_TRUNC;
if ((ofd = open(outfile, oflag, 0666)) < 0)
perror_msg_and_die("%s", outfile);
if (seek && trunc) {
if (ftruncate(ofd, seek * bs) < 0)
perror_msg_and_die("%s", outfile);
}
} else {
ofd = STDOUT_FILENO;
outfile = "standard output";
}
if (skip) {
if (lseek(ifd, skip * bs, SEEK_CUR) < 0)
perror_msg_and_die("%s", infile);
}
if (seek) {
if (lseek(ofd, seek * bs, SEEK_CUR) < 0)
perror_msg_and_die("%s", outfile);
}
while (in_full + in_part != count) {
n = safe_read(ifd, buf, bs);
if (n < 0)
perror_msg_and_die("%s", infile);
if (n == 0)
break;
if (n == bs)
in_full++;
else
in_part++;
if (sync_flag) {
memset(buf + n, '\0', bs - n);
n = bs;
}
n = full_write(ofd, buf, n);
if (n < 0)
perror_msg_and_die("%s", outfile);
if (n == bs)
out_full++;
else
out_part++;
}
fprintf(stderr, "%ld+%ld records in\n", (long)in_full, (long)in_part);
fprintf(stderr, "%ld+%ld records out\n", (long)out_full, (long)out_part);
return EXIT_SUCCESS;
}