summaryrefslogtreecommitdiffstats
path: root/usr/gzip/util.c
blob: 22ff6e5d2dfc91cb46abbd60d473ff69a0abeb87 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
/* util.c -- utility functions for gzip support
 * Copyright (C) 1992-1993 Jean-loup Gailly
 * This is free software; you can redistribute it and/or modify it under the
 * terms of the GNU General Public License, see the file COPYING.
 */

#ifdef RCSID
static char rcsid[] = "$Id: util.c,v 1.1 2002/08/18 00:59:21 hpa Exp $";
#endif

#include <ctype.h>
#include <errno.h>
#include <sys/types.h>

#include "tailor.h"

#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>

#include "gzip.h"

extern ulg crc_32_tab[];   /* crc table, defined below */

/* ===========================================================================
 * Copy input to output unchanged: zcat == cat with --force.
 * IN assertion: insize bytes have already been read in inbuf.
 */
int copy(in, out)
    int in, out;   /* input and output file descriptors */
{
    errno = 0;
    while (insize != 0 && (int)insize != EOF) {
	write_buf(out, (char*)inbuf, insize);
	bytes_out += insize;
	insize = read(in, (char*)inbuf, INBUFSIZ);
    }
    if ((int)insize == EOF && errno != 0) {
	read_error();
    }
    bytes_in = bytes_out;
    return OK;
}

/* ===========================================================================
 * Run a set of bytes through the crc shift register.  If s is a NULL
 * pointer, then initialize the crc shift register contents instead.
 * Return the current crc in either case.
 */
ulg updcrc(s, n)
    uch *s;                 /* pointer to bytes to pump through */
    unsigned n;             /* number of bytes in s[] */
{
    register ulg c;         /* temporary variable */

    static ulg crc = (ulg)0xffffffffL; /* shift register contents */

    if (s == NULL) {
	c = 0xffffffffL;
    } else {
	c = crc;
        if (n) do {
            c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
        } while (--n);
    }
    crc = c;
    return c ^ 0xffffffffL;       /* (instead of ~c for 64-bit machines) */
}

/* ===========================================================================
 * Clear input and output buffers
 */
void clear_bufs()
{
    outcnt = 0;
    insize = inptr = 0;
    bytes_in = bytes_out = 0L;
}

/* ===========================================================================
 * Fill the input buffer. This is called only when the buffer is empty.
 */
int fill_inbuf(eof_ok)
    int eof_ok;          /* set if EOF acceptable as a result */
{
    int len;

    /* Read as much as possible */
    insize = 0;
    errno = 0;
    do {
	len = read(ifd, (char*)inbuf+insize, INBUFSIZ-insize);
        if (len == 0 || len == EOF) break;
	insize += len;
    } while (insize < INBUFSIZ);

    if (insize == 0) {
	if (eof_ok) return EOF;
	read_error();
    }
    bytes_in += (ulg)insize;
    inptr = 1;
    return inbuf[0];
}

/* ===========================================================================
 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
 * (used for the compressed data only)
 */
void flush_outbuf()
{
    if (outcnt == 0) return;

    write_buf(ofd, (char *)outbuf, outcnt);
    bytes_out += (ulg)outcnt;
    outcnt = 0;
}

/* ===========================================================================
 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 * (Used for the decompressed data only.)
 */
void flush_window()
{
    if (outcnt == 0) return;
    updcrc(window, outcnt);

    if (!test) {
	write_buf(ofd, (char *)window, outcnt);
    }
    bytes_out += (ulg)outcnt;
    outcnt = 0;
}

/* ===========================================================================
 * Does the same as write(), but also handles partial pipe writes and checks
 * for error return.
 */
void write_buf(fd, buf, cnt)
    int       fd;
    voidp     buf;
    unsigned  cnt;
{
    unsigned  n;

    while ((n = write(fd, buf, cnt)) != cnt) {
	if (n == (unsigned)(-1)) {
	    write_error();
	}
	cnt -= n;
	buf = (voidp)((char*)buf+n);
    }
}

/* ========================================================================
 * Put string s in lower case, return s.
 */
char *strlwr(s)
    char *s;
{
    char *t;
    for (t = s; *t; t++) *t = tolow(*t);
    return s;
}

/* ========================================================================
 * Return the base name of a file (remove any directory prefix and
 * any version suffix). For systems with file names that are not
 * case sensitive, force the base name to lower case.
 */
char *basename(fname)
    char *fname;
{
    char *p;

    if ((p = strrchr(fname, PATH_SEP))  != NULL) fname = p+1;
    if (casemap('A') == 'a') strlwr(fname);
    return fname;
}

/* ========================================================================
 * Add an environment variable (if any) before argv, and update argc.
 * Return the expanded environment variable to be freed later, or NULL
 * if no options were added to argv.
 */
#define SEPARATOR	" \t"	/* separators in env variable */

char *add_envopt(argcp, argvp, env)
    int *argcp;          /* pointer to argc */
    char ***argvp;       /* pointer to argv */
    char *env;           /* name of environment variable */
{
    char *p;             /* running pointer through env variable */
    char **oargv;        /* runs through old argv array */
    char **nargv;        /* runs through new argv array */
    int	 oargc = *argcp; /* old argc */
    int  nargc = 0;      /* number of arguments in env variable */

    env = (char*)getenv(env);
    if (env == NULL) return NULL;

    p = (char*)xmalloc(strlen(env)+1);
    env = strcpy(p, env);                    /* keep env variable intact */

    for (p = env; *p; nargc++ ) {            /* move through env */
	p += strspn(p, SEPARATOR);	     /* skip leading separators */
	if (*p == '\0') break;

	p += strcspn(p, SEPARATOR);	     /* find end of word */
	if (*p) *p++ = '\0';		     /* mark it */
    }
    if (nargc == 0) {
	free(env);
	return NULL;
    }
    *argcp += nargc;
    /* Allocate the new argv array, with an extra element just in case
     * the original arg list did not end with a NULL.
     */
    nargv = (char**)calloc(*argcp+1, sizeof(char *));
    if (nargv == NULL) error("out of memory");
    oargv  = *argvp;
    *argvp = nargv;

    /* Copy the program name first */
    if (oargc-- < 0) error("argc<=0");
    *(nargv++) = *(oargv++);

    /* Then copy the environment args */
    for (p = env; nargc > 0; nargc--) {
	p += strspn(p, SEPARATOR);	     /* skip separators */
	*(nargv++) = p;			     /* store start */
	while (*p++) ;			     /* skip over word */
    }

    /* Finally copy the old args and add a NULL (usual convention) */
    while (oargc--) *(nargv++) = *(oargv++);
    *nargv = NULL;
    return env;
}

/* ========================================================================
 * Error handlers.
 */
void error(m)
    char *m;
{
    fprintf(stderr, "\n%s: %s: %s\n", progname, ifname, m);
    abort_gzip();
}

void warn(a, b)
    char *a, *b;            /* message strings juxtaposed in output */
{
    WARN((stderr, "%s: %s: warning: %s%s\n", progname, ifname, a, b));
}

void read_error()
{
    fprintf(stderr, "\n%s: ", progname);
    if (errno != 0) {
	perror(ifname);
    } else {
	fprintf(stderr, "%s: unexpected end of file\n", ifname);
    }
    abort_gzip();
}

void write_error()
{
    fprintf(stderr, "\n%s: ", progname);
    perror(ofname);
    abort_gzip();
}

/* ========================================================================
 * Display compression ratio on the given stream on 6 characters.
 */
void display_ratio(num, den, file)
    long num;
    long den;
    FILE *file;
{
    long ratio;  /* 1000 times the compression ratio */
    char sign;

    if (den == 0) {
	ratio = 0; /* no compression */
    } else if (den < 2147483L) { /* (2**31 -1)/1000 */
	ratio = 1000L*num/den;
    } else {
	ratio = num/(den/1000L);
    }
    if (ratio < 0) {
	sign = '-';
	ratio = -ratio;
    } else {
	sign = ' ';
    }
    fprintf(file, "%c%2ld.%1ld%%", sign, ratio / 10L, ratio % 10L);
}


/* ========================================================================
 * Semi-safe malloc -- never returns NULL.
 */
voidp xmalloc (size)
    unsigned size;
{
    voidp cp = (voidp)malloc (size);

    if (cp == NULL) error("out of memory");
    return cp;
}

/* ========================================================================
 * Table of CRC-32's of all single-byte values (made by makecrc.c)
 */
ulg crc_32_tab[] = {
  0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
  0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
  0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
  0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
  0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
  0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
  0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
  0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
  0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
  0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
  0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
  0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
  0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
  0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
  0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
  0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
  0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
  0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
  0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
  0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
  0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
  0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
  0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
  0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
  0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
  0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
  0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
  0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
  0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
  0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
  0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
  0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
  0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
  0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
  0x2d02ef8dL
};