OpenSolaris_b135/cmd/pack/pack.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Huffman encoding program
* Usage: pack [[ -f ] [ - ] [-/] filename ... ] filename ...
* - option: enable/disable listing of statistics
*/
#include <locale.h>
#include <stdarg.h>
#include <sys/isa_defs.h>
#include <sys/param.h>
#include <utime.h>
#include <sys/acl.h>
#include <aclutils.h>
#include <libcmdutils.h>
#undef lint
#define END 256
#define PACKED 017436 /* <US><RS> - Unlikely value */
#define SUF0 '.'
#define SUF1 'z'
struct stat status, ostatus;
static struct utimbuf u_times;
/* union for overlaying a long int with a set of four characters */
union FOUR {
struct { long int lng; } lint;
struct { char c0, c1, c2, c3; } chars;
};
/* character counters */
long count [END+1];
union FOUR insize;
long outsize;
long dictsize;
int diffbytes;
/* i/o stuff */
char vflag = 0;
int force = 0; /* allow forced packing for consistency in directory */
static char filename [MAXPATHLEN];
static int max_name;
int infile; /* unpacked file */
int outfile; /* packed file */
char inbuff [BUFSIZ];
char outbuff [BUFSIZ+4];
/* variables associated with the tree */
int maxlev;
int levcount [25];
int lastnode;
int parent [2*END+1];
/* variables associated with the encoding process */
char length [END+1];
long bits [END+1];
union FOUR mask;
long inc;
#if defined(_LITTLE_ENDIAN)
char *maskshuff[4] = {&(mask.chars.c3),
&(mask.chars.c2),
&(mask.chars.c1),
&(mask.chars.c0)};
#elif defined(_BIG_ENDIAN)
char *maskshuff[4] = {&(mask.chars.c0),
&(mask.chars.c1),
&(mask.chars.c2),
&(mask.chars.c3)};
#else
#error Unknown byte ordering!
#endif
/* the heap */
int n;
struct heap {
long int count;
int node;
} heap [END+2];
#define hmove(a, b) {(b).count = (a).count; (b).node = (a).node; }
static void heapify(int i);
/* Extended system attribute support */
static int saflg = 0;
/* gather character frequency statistics */
/* return 1 if successful, 0 otherwise */
int
input(char *source)
{
register int i;
for (i = 0; i < END; i++)
count[i] = 0;
while ((i = read(infile, inbuff, BUFSIZ)) > 0)
while (i > 0)
count[inbuff[--i]&0377] += 2;
if (i == 0)
return (1);
(void) fprintf(stderr, gettext(
"pack: %s: read error - file unchanged: "), source);
perror("");
return (0);
}
/* encode the current file */
/* return 1 if successful, 0 otherwise */
int
output(char *source)
{
int c, i, inleft;
char *inp;
register char **q, *outp;
register int bitsleft;
long temp;
/* output ``PACKED'' header */
outbuff[0] = 037; /* ascii US */
outbuff[1] = 036; /* ascii RS */
/* output the length and the dictionary */
temp = insize.lint.lng;
for (i = 5; i >= 2; i--) {
outbuff[i] = (char)(temp & 0377);
temp >>= 8;
}
outp = &outbuff[6];
*outp++ = maxlev;
for (i = 1; i < maxlev; i++)
*outp++ = levcount[i];
*outp++ = levcount[maxlev]-2;
for (i = 1; i <= maxlev; i++)
for (c = 0; c < END; c++)
if (length[c] == i)
*outp++ = c;
dictsize = outp-&outbuff[0];
/* output the text */
(void) lseek(infile, 0L, 0);
outsize = 0;
bitsleft = 8;
inleft = 0;
do {
if (inleft <= 0) {
inleft = read(infile, inp = &inbuff[0], BUFSIZ);
if (inleft < 0) {
(void) fprintf(stderr, gettext(
"pack: %s: read error - file unchanged: "),
source);
perror("");
return (0);
}
}
c = (--inleft < 0) ? END : (*inp++ & 0377);
mask.lint.lng = bits[c]<<bitsleft;
q = &maskshuff[0];
if (bitsleft == 8)
*outp = **q++;
else
*outp |= **q++;
bitsleft -= length[c];
while (bitsleft < 0) {
*++outp = **q++;
bitsleft += 8;
}
if (outp >= &outbuff[BUFSIZ]) {
if (write(outfile, outbuff, BUFSIZ) != BUFSIZ) {
wrerr: (void) fprintf(stderr, gettext(
"pack: %s.z: write error - "
"file unchanged: "), source);
perror("");
return (0);
}
((union FOUR *)outbuff)->lint.lng =
((union FOUR *)&outbuff[BUFSIZ])->lint.lng;
outp -= BUFSIZ;
outsize += BUFSIZ;
}
} while (c != END);
if (bitsleft < 8)
outp++;
c = outp-outbuff;
if (write(outfile, outbuff, c) != c)
goto wrerr;
outsize += c;
return (1);
}
/* makes a heap out of heap[i],...,heap[n] */
void
heapify(int i)
{
register int k;
int lastparent;
struct heap heapsubi;
hmove(heap[i], heapsubi);
lastparent = n/2;
while (i <= lastparent) {
k = 2*i;
if (heap[k].count > heap[k+1].count && k < n)
k++;
if (heapsubi.count < heap[k].count)
break;
hmove(heap[k], heap[i]);
i = k;
}
hmove(heapsubi, heap[i]);
}
/* return 1 after successful packing, 0 otherwise */
int
packfile(char *source)
{
register int c, i, p;
long bitsout;
/* gather frequency statistics */
if (input(source) == 0)
return (0);
/* put occurring chars in heap with their counts */
diffbytes = -1;
count[END] = 1;
insize.lint.lng = n = 0;
for (i = END; i >= 0; i--) {
parent[i] = 0;
if (count[i] > 0) {
diffbytes++;
insize.lint.lng += count[i];
heap[++n].count = count[i];
heap[n].node = i;
}
}
if (diffbytes == 1) {
(void) fprintf(stderr, gettext(
"pack: %s: trivial file - file unchanged\n"), source);
return (0);
}
insize.lint.lng >>= 1;
for (i = n/2; i >= 1; i--)
heapify(i);
/* build Huffman tree */
lastnode = END;
while (n > 1) {
parent[heap[1].node] = ++lastnode;
inc = heap[1].count;
hmove(heap[n], heap[1]);
n--;
heapify(1);
parent[heap[1].node] = lastnode;
heap[1].node = lastnode;
heap[1].count += inc;
heapify(1);
}
parent[lastnode] = 0;
/* assign lengths to encoding for each character */
bitsout = maxlev = 0;
for (i = 1; i <= 24; i++)
levcount[i] = 0;
for (i = 0; i <= END; i++) {
c = 0;
for (p = parent[i]; p != 0; p = parent[p])
c++;
levcount[c]++;
length[i] = c;
if (c > maxlev)
maxlev = c;
bitsout += c*(count[i]>>1);
}
if (maxlev > 24) {
/* can't occur unless insize.lint.lng >= 2**24 */
(void) fprintf(stderr, gettext(
"pack: %s: Huffman tree has too many levels - "
"file unchanged\n"), source);
return (0);
}
/* don't bother if no compression results */
outsize = ((bitsout+7)>>3)+6+maxlev+diffbytes;
if ((insize.lint.lng+BUFSIZ-1)/BUFSIZ <=
(outsize+BUFSIZ-1)/BUFSIZ && !force) {
(void) printf(gettext(
"pack: %s: no saving - file unchanged\n"), source);
return (0);
}
/* compute bit patterns for each character */
inc = 1L << 24;
inc >>= maxlev;
mask.lint.lng = 0;
for (i = maxlev; i > 0; i--) {
for (c = 0; c <= END; c++)
if (length[c] == i) {
bits[c] = mask.lint.lng;
mask.lint.lng += inc;
}
mask.lint.lng &= ~inc;
inc <<= 1;
}
return (output(source));
}
int
main(int argc, char *argv[])
{
extern int optind;
register int i;
register char *cp;
int k, sep, errflg = 0;
int c;
int error;
int fcount = 0; /* count failures */
acl_t *aclp = NULL;
char *progname;
int sattr_exist = 0;
int xattr_exist = 0;
(void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */
#endif
(void) textdomain(TEXT_DOMAIN);
if (progname = strrchr(argv[0], '/'))
++progname;
else
progname = argv[0];
while ((c = getopt(argc, argv, "f-/")) != EOF) {
if (c == 'f')
force++;
else if (c == '/')
saflg++;
else
++errflg;
}
/*
* Check for invalid option. Also check for missing
* file operand, ie: "pack" or "pack -".
*/
argc -= optind;
argv = &argv[optind];
if (errflg || argc < 1 ||
(argc == 1 && (argv[0][0] == '-' || argv[0][0] == '/' &&
argv[0][1] == '\0'))) {
(void) fprintf(stderr, gettext(
"usage: pack [-f] [-] [-/] file...\n"));
if (argc < 1 ||
(argc == 1 && (argv[0][0] == '-' || argv[0][0] == '/') &&
argv[0][1] == '\0')) {
/*
* return 1 for usage error when no file was specified
*/
return (1);
}
}
/* loop through the file names */
for (k = 0; k < argc; k++) {
if (argv[k][0] == '-' && argv[k][1] == '\0') {
vflag = 1 - vflag;
continue;
}
fcount++; /* increase failure count - expect the worst */
if (errflg) {
/*
* invalid option; just count the number of files not
* packed
*/
continue;
}
/* remove any .z suffix the user may have added */
for (cp = argv[k]; *cp != '\0'; ++cp)
;
if (cp[-1] == SUF1 && cp[-2] == SUF0) {
*cp-- = '\0'; *cp-- = '\0'; *cp = '\0';
}
sep = -1; cp = filename;
max_name = pathconf(argv[k], _PC_NAME_MAX);
if (max_name == -1) {
/* pathname invalid or no limit on length of filename */
max_name = _POSIX_NAME_MAX;
}
/* copy argv[k] to filename and count chars in base name */
for (i = 0; i < (MAXPATHLEN-3) && (*cp = argv[k][i]); i++)
if (*cp++ == '/') sep = i;
if ((infile = open(filename, 0)) < 0) {
(void) fprintf(stderr, gettext(
"pack: %s: cannot open: "), filename);
perror("");
continue;
}
if (i >= (MAXPATHLEN-3) || (i-sep) > (max_name - 1)) {
(void) fprintf(stderr, gettext(
"pack: %s: file name too long\n"), argv[k]);
continue;
}
(void) fstat(infile, &status);
if (S_ISDIR(status.st_mode)) {
(void) fprintf(stderr, gettext(
"pack: %s: cannot pack a directory\n"),
argv[k]);
goto closein;
}
if (status.st_size == 0) {
(void) fprintf(stderr, gettext(
"pack: %s: cannot pack a zero length file\n"),
argv[k]);
goto closein;
}
if (status.st_nlink != 1) {
(void) fprintf(stderr, gettext(
"pack: %s: has links\n"),
argv[k]);
goto closein;
}
*cp++ = SUF0; *cp++ = SUF1; *cp = '\0';
if (stat(filename, &ostatus) != -1) {
(void) fprintf(stderr, gettext(
"pack: %s: already exists\n"), filename);
goto closein;
}
if ((outfile = creat(filename, status.st_mode | O_RDONLY))
< 0) {
(void) fprintf(stderr, gettext(
"pack: %s: cannot create: "), filename);
perror("");
goto closein;
}
error = facl_get(infile, ACL_NO_TRIVIAL, &aclp);
if (error != 0) {
(void) fprintf(stderr, gettext(
"pack: %s: cannot retrieve ACL: %s\n"), argv[k],
acl_strerror(error));
}
if (packfile(argv[k])) {
if (pathconf(argv[k], _PC_XATTR_EXISTS) == 1)
xattr_exist = 1;
if (saflg && sysattr_support(argv[k],
_PC_SATTR_EXISTS) == 1)
sattr_exist = 1;
if (sattr_exist || xattr_exist) {
if (mv_xattrs(progname, argv[k], filename,
sattr_exist, 0) != 0) {
/* Move attributes back ... */
xattr_exist = 0;
sattr_exist = 0;
if (pathconf(filename,
_PC_XATTR_EXISTS) == 1)
xattr_exist = 1;
if (saflg && sysattr_support(filename,
_PC_SATTR_EXISTS) == 1)
sattr_exist = 1;
if (xattr_exist || sattr_exist) {
(void) mv_xattrs(progname,
filename, argv[k],
sattr_exist, 1);
(void) unlink(filename);
goto out;
}
} else {
errno = 0;
if (unlink(argv[k]) != 0) {
(void) fprintf(stderr, gettext(
"pack: %s :cannot unlink:"),
argv[k]);
if (errno == EPERM)
perror("No permission");
else
perror("");
}
}
} else {
errno = 0;
if (unlink(argv[k]) != 0) {
(void) fprintf(stderr, gettext(
"pack: %s :cannot unlink"),
argv[k]);
if (errno == EPERM)
perror("No permission");
else
perror("");
}
}
(void) printf(gettext(
"pack: %s: %.1f%% Compression\n"),
argv[k],
((double)(-outsize+(insize.lint.lng))/
(double)insize.lint.lng)*100);
/* output statistics */
if (vflag) {
(void) printf(gettext(
"\tfrom %ld to %ld bytes\n"),
insize.lint.lng, outsize);
(void) printf(gettext(
"\tHuffman tree has %d levels below "
"root\n"), maxlev);
(void) printf(gettext(
"\t%d distinct bytes in input\n"),
diffbytes);
(void) printf(gettext(
"\tdictionary overhead = %ld bytes\n"),
dictsize);
(void) printf(gettext(
"\teffective entropy = %.2f bits/byte\n"),
((double)outsize / (double)insize.lint.lng)
* 8);
(void) printf(gettext(
"\tasymptotic entropy = %.2f bits/byte\n"),
((double)(outsize-dictsize) /
(double)insize.lint.lng) * 8);
}
u_times.actime = status.st_atime;
u_times.modtime = status.st_mtime;
if (utime(filename, &u_times) != 0) {
errflg++;
(void) fprintf(stderr,
gettext(
"pack: cannot change times on %s: "),
filename);
perror("");
}
if (chmod(filename, status.st_mode) != 0) {
errflg++;
(void) fprintf(stderr,
gettext(
"pack: can't change mode to %o on %s: "),
status.st_mode, filename);
perror("");
}
(void) chown(filename, status.st_uid, status.st_gid);
if (aclp && (facl_set(outfile, aclp) < 0)) {
(void) fprintf(stderr, gettext(
"pack: %s: failed to set acl entries\n"),
filename);
perror("");
}
if (!errflg)
fcount--; /* success after all */
}
out:
if (aclp) {
acl_free(aclp);
aclp = NULL;
}
closein: (void) close(outfile);
(void) close(infile);
}
return (fcount);
}