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/* dd.c - program to convert and copy a file.
*
* Copyright 2013 Ashwini Kumar <ak.ashwini@gmail.com>
* Copyright 2013 Kyungwan Han <asura321@gmail.com>
*
* See http://opengroup.org/onlinepubs/9699919799/utilities/dd.html
USE_DD(NEWTOY(dd, 0, TOYFLAG_USR|TOYFLAG_BIN))
config DD
bool "dd"
default n
help
usage: dd [if=FILE] [of=FILE] [ibs=N] [obs=N] [iflag=FLAGS] [oflag=FLAGS]
[bs=N] [count=N] [seek=N] [skip=N]
[conv=notrunc|noerror|sync|fsync] [status=noxfer|none]
Copy/convert files.
if=FILE Read from FILE instead of stdin
of=FILE Write to FILE instead of stdout
bs=N Read and write N bytes at a time
ibs=N Input block size
obs=N Output block size
count=N Copy only N input blocks
skip=N Skip N input blocks
seek=N Skip N output blocks
iflag=FLAGS Set input flags
oflag=FLAGS Set output flags
conv=notrunc Don't truncate output file
conv=noerror Continue after read errors
conv=sync Pad blocks with zeros
conv=fsync Physically write data out before finishing
status=noxfer Don't show transfer rate
status=none Don't show transfer rate or records in/out
FLAGS is a comma-separated list of:
count_bytes (iflag) interpret count=N in bytes, not blocks
seek_bytes (oflag) interpret seek=N in bytes, not blocks
skip_bytes (iflag) interpret skip=N in bytes, not blocks
Numbers may be suffixed by c (*1), w (*2), b (*512), kD (*1000), k (*1024),
MD (*1000*1000), M (*1024*1024), GD (*1000*1000*1000) or G (*1024*1024*1024).
*/
#define FOR_dd
#include "toys.h"
GLOBALS(
int show_xfer, show_records;
unsigned long long bytes, c_count, in_full, in_part, out_full, out_part;
struct timeval start;
struct {
char *name;
int fd;
unsigned char *buff, *bp;
long sz, count;
unsigned long long offset;
} in, out;
unsigned conv, iflag, oflag;
)
struct dd_flag {
char *name;
};
static const struct dd_flag dd_conv[] = TAGGED_ARRAY(DD_conv,
{"fsync"}, {"noerror"}, {"notrunc"}, {"sync"},
);
static const struct dd_flag dd_iflag[] = TAGGED_ARRAY(DD_iflag,
{"count_bytes"}, {"skip_bytes"},
);
static const struct dd_flag dd_oflag[] = TAGGED_ARRAY(DD_oflag,
{"seek_bytes"},
);
static void status()
{
double seconds;
struct timeval now;
gettimeofday(&now, NULL);
seconds = ((now.tv_sec * 1000000 + now.tv_usec) -
(TT.start.tv_sec * 1000000 + TT.start.tv_usec))/1000000.0;
if (TT.show_records)
fprintf(stderr, "%llu+%llu records in\n%llu+%llu records out\n",
TT.in_full, TT.in_part, TT.out_full, TT.out_part);
if (TT.show_xfer) {
human_readable(toybuf, TT.bytes, HR_SPACE|HR_B);
fprintf(stderr, "%llu bytes (%s) copied, ", TT.bytes, toybuf);
human_readable(toybuf, TT.bytes/seconds, HR_SPACE|HR_B);
fprintf(stderr, "%f s, %s/s\n", seconds, toybuf);
}
}
static void dd_sigint(int sig)
{
toys.exitval = sig|128;
xexit();
}
static void write_out(int all)
{
TT.out.bp = TT.out.buff;
while (TT.out.count) {
ssize_t nw = writeall(TT.out.fd, TT.out.bp, ((all)? TT.out.count : TT.out.sz));
all = 0; //further writes will be on obs
if (nw <= 0) perror_exit("%s: write error", TT.out.name);
if (nw == TT.out.sz) TT.out_full++;
else TT.out_part++;
TT.out.count -= nw;
TT.out.bp += nw;
TT.bytes += nw;
if (TT.out.count < TT.out.sz) break;
}
if (TT.out.count) memmove(TT.out.buff, TT.out.bp, TT.out.count); //move remainder to front
}
static void parse_flags(char *what, char *arg,
const struct dd_flag* flags, int flag_count, unsigned *result)
{
char *pre = xstrdup(arg);
int i;
for (i=0; i<flag_count; ++i) {
while (comma_remove(pre, flags[i].name)) *result |= 1<<i;
}
if (*pre) error_exit("bad %s=%s", what, pre);
free(pre);
}
void dd_main()
{
char **args;
unsigned long long bs = 0;
int trunc = O_TRUNC;
TT.show_xfer = TT.show_records = 1;
TT.c_count = ULLONG_MAX;
TT.in.sz = TT.out.sz = 512; //default io block size
for (args = toys.optargs; *args; args++) {
char *arg = *args;
if (strstart(&arg, "bs=")) bs = atolx_range(arg, 1, LONG_MAX);
else if (strstart(&arg, "ibs=")) TT.in.sz = atolx_range(arg, 1, LONG_MAX);
else if (strstart(&arg, "obs=")) TT.out.sz = atolx_range(arg, 1, LONG_MAX);
else if (strstart(&arg, "count="))
TT.c_count = atolx_range(arg, 0, LLONG_MAX);
else if (strstart(&arg, "if=")) TT.in.name = arg;
else if (strstart(&arg, "of=")) TT.out.name = arg;
else if (strstart(&arg, "seek="))
TT.out.offset = atolx_range(arg, 0, LLONG_MAX);
else if (strstart(&arg, "skip="))
TT.in.offset = atolx_range(arg, 0, LLONG_MAX);
else if (strstart(&arg, "status=")) {
if (!strcmp(arg, "noxfer")) TT.show_xfer = 0;
else if (!strcmp(arg, "none")) TT.show_xfer = TT.show_records = 0;
else error_exit("unknown status '%s'", arg);
} else if (strstart(&arg, "conv=")) {
parse_flags("conv", arg, dd_conv, ARRAY_LEN(dd_conv), &TT.conv);
fprintf(stderr, "conv=%x\n", TT.conv);
} else if (strstart(&arg, "iflag="))
parse_flags("iflag", arg, dd_iflag, ARRAY_LEN(dd_iflag), &TT.iflag);
else if (strstart(&arg, "oflag="))
parse_flags("oflag", arg, dd_oflag, ARRAY_LEN(dd_oflag), &TT.oflag);
else error_exit("bad arg %s", arg);
}
if (bs) TT.in.sz = TT.out.sz = bs;
sigatexit(status);
xsignal(SIGINT, dd_sigint);
xsignal(SIGUSR1, status);
gettimeofday(&TT.start, NULL);
// For bs=, in/out is done as it is. so only in.sz is enough.
// With Single buffer there will be overflow in a read following partial read.
TT.in.buff = TT.out.buff = xmalloc(TT.in.sz + (bs ? 0 : TT.out.sz));
TT.in.bp = TT.out.bp = TT.in.buff;
if (!TT.in.name) TT.in.name = "stdin";
else TT.in.fd = xopenro(TT.in.name);
if (TT.conv & _DD_conv_notrunc) trunc = 0;
if (!TT.out.name) {
TT.out.name = "stdout";
TT.out.fd = 1;
} else TT.out.fd = xcreate(TT.out.name,
O_WRONLY|O_CREAT|(trunc*!TT.out.offset), 0666);
// Implement skip=
if (TT.in.offset) {
off_t off = TT.in.offset;
if (!(TT.iflag & _DD_iflag_skip_bytes)) off *= TT.in.sz;
if (lseek(TT.in.fd, off, SEEK_CUR) < 0) {
while (off > 0) {
int chunk = off < TT.in.sz ? off : TT.in.sz;
ssize_t n = read(TT.in.fd, TT.in.bp, chunk);
if (n < 0) {
perror_msg("%s", TT.in.name);
if (TT.conv & _DD_conv_noerror) status();
else return;
} else if (!n) {
xprintf("%s: Can't skip\n", TT.in.name);
return;
}
off -= n;
}
}
}
// Implement seek= and truncate as necessary. We handled position zero
// truncate with O_TRUNC on open, so output to /dev/null and such doesn't
// error.
bs = TT.out.offset;
if (!(TT.oflag & _DD_oflag_seek_bytes)) bs *= TT.out.sz;
if (bs) {
struct stat st;
xlseek(TT.out.fd, bs, SEEK_CUR);
if (trunc && !fstat(TT.out.fd, &st) && S_ISREG(st.st_mode)
&& ftruncate(TT.out.fd, bs)) perror_exit("unexpected ftruncate failure");
}
unsigned long long bytes_left = TT.c_count;
if (TT.c_count != ULLONG_MAX && !(TT.iflag & _DD_iflag_count_bytes)) {
bytes_left *= TT.in.sz;
}
while (bytes_left) {
int chunk = bytes_left < TT.in.sz ? bytes_left : TT.in.sz;
ssize_t n;
TT.in.bp = TT.in.buff + TT.in.count;
if (TT.conv & _DD_conv_sync) memset(TT.in.bp, 0, TT.in.sz);
if (!(n = read(TT.in.fd, TT.in.bp, chunk))) break;
if (n < 0) {
if (errno == EINTR) continue;
//read error case.
perror_msg("%s: read error", TT.in.name);
if (!(TT.conv & _DD_conv_noerror)) exit(1);
status();
xlseek(TT.in.fd, TT.in.sz, SEEK_CUR);
if (!(TT.conv & _DD_conv_sync)) continue;
// if SYNC, then treat as full block of nuls
n = TT.in.sz;
}
if (n == TT.in.sz) {
TT.in_full++;
TT.in.count += n;
} else {
TT.in_part++;
if (TT.conv & _DD_conv_sync) TT.in.count += TT.in.sz;
else TT.in.count += n;
}
bytes_left -= n;
TT.out.count = TT.in.count;
if (bs) {
write_out(1);
TT.in.count = 0;
continue;
}
if (TT.in.count >= TT.out.sz) {
write_out(0);
TT.in.count = TT.out.count;
}
}
if (TT.out.count) write_out(1); //write any remaining input blocks
if ((TT.conv & _DD_conv_fsync) && fsync(TT.out.fd)<0)
perror_exit("%s: fsync", TT.out.name);
close(TT.in.fd);
close(TT.out.fd);
if (TT.in.buff) free(TT.in.buff);
}