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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);
- }
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