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new version from Keith Muller
[unix-history] / usr / src / bin / dd / dd.c
/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Keith Muller of the University of California, San Diego.
*
* %sccs.include.redist.c%
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1991 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)dd.c 5.4 (Berkeley) %G%";
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <signal.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "dd.h"
#include "extern.h"
static void dd_close __P((void));
static void dd_in __P((void));
static void setup __P((void));
struct io_desc in, out; /* input/output state */
void (*cfunc)(); /* conversion function */
u_long cpy_cnt; /* # of blocks to copy */
u_int ddflags; /* conversion options */
u_int cbsz; /* conversion block size */
u_int files_cnt = 1; /* # of files to copy */
u_char *ctab; /* conversion table */
main(argc, argv)
int argc;
char **argv;
{
jcl(argv);
setup();
(void)signal(SIGINFO, summary);
(void)signal(SIGINT, terminate);
while (files_cnt--)
dd_in();
dd_close();
summary(0);
exit(0);
}
static void
setup()
{
register u_int cnt;
struct stat sb;
struct mtget mt;
if (in.name == NULL) {
in.name = "stdin";
in.fd = STDIN_FILENO;
} else {
in.fd = open(in.name, O_RDONLY, 0);
if (in.fd < 0)
err("%s: %s", in.name, strerror(errno));
}
if (fstat(in.fd, &sb))
err("%s: %s", in.name, strerror(errno));
if (S_ISCHR(sb.st_mode))
in.flags |= ioctl(in.fd, MTIOCGET, &mt) ? ISCHR : ISTAPE;
else if (lseek(in.fd, 0L, SEEK_CUR) == -1 && errno == ESPIPE)
in.flags |= ISPIPE; /* XXX fixed in 4.4BSD */
if (files_cnt > 1 && !(in.flags & ISTAPE))
err("files is not supported for non-tape devices");
if (out.name == NULL) {
/* No way to check for read access here. */
out.fd = STDOUT_FILENO;
out.name = "stdout";
} else {
out.fd = open(out.name, O_RDWR|O_CREAT, DEFFILEMODE);
/*
* May not have read access, so try again with write only.
* Without read we may have a problem if output also does
* not support seeks.
*/
if (out.fd < 0) {
out.fd = open(out.name, O_WRONLY|O_CREAT, DEFFILEMODE);
out.flags |= NOREAD;
}
if (out.fd < 0)
err("%s: %s", out.name, strerror(errno));
}
if (fstat(out.fd, &sb))
err("%s: %s", out.name, strerror(errno));
if (S_ISCHR(sb.st_mode))
out.flags |= ioctl(out.fd, MTIOCGET, &mt) ? ISCHR : ISTAPE;
else if (lseek(out.fd, 0L, SEEK_CUR) == -1 && errno == ESPIPE)
out.flags |= ISPIPE; /* XXX fixed in 4.4BSD */
/*
* Allocate space for the input and output buffers. If not doing
* record oriented I/O, only need a single buffer.
*/
if (!(ddflags & (C_BLOCK|C_UNBLOCK))) {
if (in.dbsz > out.dbsz)
cnt = in.dbsz - 1 - in.dbsz / 2 + in.dbsz;
else if (in.dbsz < out.dbsz)
cnt = out.dbsz + in.dbsz - 1;
else
cnt = in.dbsz;
if ((in.db = malloc(cnt)) == NULL)
err("%s", strerror(errno));
out.db = in.db;
} else if ((in.db =
malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL ||
(out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL)
err("%s", strerror(errno));
in.dbp = in.db;
out.dbp = out.db;
/* Position the input/output streams. */
if (in.offset)
pos_in();
if (out.offset)
pos_out();
/* Truncate the output file. */
if (ddflags & C_NOTRUNC) {
if (out.flags & ISTAPE)
err("notrunc is not supported for tape devices");
} else if (S_ISREG(sb.st_mode) && ftruncate(out.fd,
(off_t)out.offset * out.dbsz))
err("%s: truncate: %s", out.name, strerror(errno));
/*
* If converting case at the same time as another conversion, build a
* table that does both at once. If just converting case, use the
* built-in tables.
*/
if (ddflags & (C_LCASE|C_UCASE))
if (ddflags & C_BLOCK)
if (ddflags & C_LCASE) {
for (cnt = 0; cnt < 0377; ++cnt)
if (isupper(cnt))
ctab[cnt] = ctab[tolower(cnt)];
} else {
for (cnt = 0; cnt < 0377; ++cnt)
if (islower(cnt))
ctab[cnt] = ctab[toupper(cnt)];
}
else if (ddflags & C_UNBLOCK)
if (ddflags & C_LCASE) {
for (cnt = 0; cnt < 0377; ++cnt)
if (isupper(ctab[cnt]))
ctab[cnt] = tolower(ctab[cnt]);
} else {
for (cnt = 0; cnt < 0377; ++cnt)
if (islower(ctab[cnt]))
ctab[cnt] = toupper(ctab[cnt]);
}
else {
extern u_char l2u[], u2l[];
ctab = ddflags & C_LCASE ? u2l : l2u;
}
}
static void
dd_in()
{
register int flags, n;
for(flags = ddflags;;) {
if (cpy_cnt && (in.f_stats + in.p_stats) >= cpy_cnt)
return;
/*
* Zero the buffer first if trying to recover from errors so
* lose the minimum amount of data. If doing block operations
* use spaces.
*/
if (flags & (C_NOERROR|C_SYNC))
if (flags & (C_BLOCK|C_UNBLOCK))
memset(in.dbp, ' ', in.dbsz);
else
bzero(in.dbp, in.dbsz);
n = read(in.fd, in.dbp, in.dbsz);
if (n == 0) {
in.dbrcnt = 0;
return;
}
/* Read error. */
if (n < 0) {
/*
* If noerror not specified, die. POSIX requires that
* the warning message be followed by an I/O display.
*/
if (!(flags & C_NOERROR))
err("%s: %s", in.name, strerror(errno));
warn("%s: %s", in.name, strerror(errno));
summary(0);
/*
* If it's not a tape drive or a pipe, seek past the
* error. If your OS doesn't do the right thing for
* raw disks this section should be modified to re-read
* in sector size chunks.
*/
if (!(in.flags & (ISPIPE|ISTAPE)) &&
lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
warn("%s: %s", in.name, strerror(errno));
/* If sync not specified, omit block and continue. */
if (!(ddflags & C_SYNC))
continue;
/* Read errors count as full blocks. */
in.dbcnt += in.dbrcnt = in.dbsz;
++in.f_stats;
/* Handle full input blocks. */
} else if (n == in.dbsz) {
in.dbcnt += in.dbrcnt = n;
++in.f_stats;
/* Handle partial input blocks. */
} else if (n != in.dbsz) {
/* If sync, fill the block with NULs. */
if (ddflags & C_SYNC) {
bzero(in.dbp + n, in.dbsz - n);
in.dbcnt += in.dbrcnt = in.dbsz;
} else
in.dbcnt += in.dbrcnt = n;
++in.p_stats;
}
/*
* POSIX states that if bs is set and no other conversions
* are specified, the block is output as it is read, without
* buffering.
*/
if (ddflags & C_BS) {
out.dbcnt = in.dbcnt;
dd_out(1);
in.dbcnt = 0;
continue;
}
if (ddflags & C_SWAB) {
if ((n = in.dbcnt) & 1) {
warn("%s: odd swab count", in.name);
--n;
}
swab(in.dbp, in.dbp, n);
}
in.dbp += in.dbrcnt;
(*cfunc)();
}
}
/*
* Cleanup any remaining I/O and flush output. If necesssary, output file
* is truncated.
*/
static void
dd_close()
{
if (cfunc == def)
def_close();
else if (cfunc == block)
block_close();
else if (cfunc == unblock)
unblock_close();
if (out.dbcnt)
dd_out(1);
}
void
dd_out(force)
int force;
{
static int warned;
register int cnt, n, nw;
register u_char *outp;
/*
* Write one or more blocks out. The common case is writing a full
* output block in a single write; increment the full block stats.
* Otherwise, we're into partial block writes. If a partial write,
* and it's a character device, just warn. If a tape device, quit.
*
* The partial writes represent two cases. 1: Where the input block
* was less than expected so the output block was less than expected.
* 2: Where the input block was the right size but we were forced to
* write the block in multiple chunks. The original versions of dd(1)
* never wrote a block in more than a single write, so the latter case
* never happened.
*
* One special case is if we're forced to do the write -- in that case
* we play games with the buffer size, and it's usually a partial write.
*/
outp = out.db;
for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
for (cnt = n;; cnt -= nw) {
outp += nw = write(out.fd, outp, cnt);
if (nw == n) {
if (n != out.dbsz)
++out.p_stats;
else
++out.f_stats;
break;
}
if (nw < 0)
err("%s: %s", out.name, strerror(errno));
++out.p_stats;
if (nw == cnt)
break;
if (out.flags & ISCHR && !warned) {
warned = 1;
warn("%s: short write on character device",
out.name);
}
if (out.flags & ISTAPE)
err("%s: short write on tape device", out.name);
}
if ((out.dbcnt -= n) < out.dbsz)
break;
}
/* Reassemble the output block. */
if (out.dbcnt)
bcopy(out.dbp - out.dbcnt, out.db, out.dbcnt);
out.dbp = out.db + out.dbcnt;
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.