usr.bin/patch/util.c

   1 /*
   2  * $OpenBSD: util.c,v 1.32 2006/03/11 19:41:30 otto Exp $
   3  * $DragonFly: src/usr.bin/patch/util.c,v 1.9 2007/09/29 23:11:10 swildner Exp $
   4  */
   5
   6 /*
   7  * patch - a program to apply diffs to original files
   8  *
   9  * Copyright 1986, Larry Wall
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following condition is met:
  13  * 1. Redistributions of source code must retain the above copyright notice,
  14  * this condition and the following disclaimer.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  29  * behaviour
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/stat.h>
  34
  35 #include <ctype.h>
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <libgen.h>
  39 #include <paths.h>
  40 #include <signal.h>
  41 #include <stdarg.h>
  42 #include <stdlib.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46
  47 #include "common.h"
  48 #include "util.h"
  49 #include "backupfile.h"
  50 #include "pathnames.h"
  51
  52 /* Rename a file, copying it if necessary. */
  53
  54 int
  55 move_file(const char *from, const char *to)
  56 {
  57         int     fromfd;
  58         ssize_t i;
  59
  60         /* to stdout? */
  61
  62         if (strEQ(to, "-")) {
  63 #ifdef DEBUGGING
  64                 if (debug & 4)
  65                         say("Moving %s to stdout.\n", from);
  66 #endif
  67                 fromfd = open(from, O_RDONLY);
  68                 if (fromfd < 0)
  69                         pfatal("internal error, can't reopen %s", from);
  70                 while ((i = read(fromfd, buf, buf_len)) > 0)
  71                         if (write(STDOUT_FILENO, buf, i) != i)
  72                                 pfatal("write failed");
  73                 close(fromfd);
  74                 return 0;
  75         }
  76         if (backup_file(to) < 0) {
  77                 say("Can't backup %s, output is in %s: %s\n", to, from,
  78                     strerror(errno));
  79                 return -1;
  80         }
  81 #ifdef DEBUGGING
  82         if (debug & 4)
  83                 say("Moving %s to %s.\n", from, to);
  84 #endif
  85         if (rename(from, to) < 0) {
  86                 if (errno != EXDEV || copy_file(from, to) < 0) {
  87                         say("Can't create %s, output is in %s: %s\n",
  88                             to, from, strerror(errno));
  89                         return -1;
  90                 }
  91         }
  92         return 0;
  93 }
  94
  95 /* Backup the original file.  */
  96
  97 int
  98 backup_file(const char *orig)
  99 {
 100         struct stat     filestat;
 101         char            bakname[MAXPATHLEN], *s, *simplename;
 102         dev_t           orig_device;
 103         ino_t           orig_inode;
 104
 105         if (backup_type == none || stat(orig, &filestat) != 0)
 106                 return 0;                       /* nothing to do */
 107         /*
 108          * If the user used zero prefixes or suffixes, then
 109          * he doesn't want backups.  Yet we have to remove
 110          * orig to break possible hardlinks.
 111          */
 112         if ((origprae && *origprae == 0) || *simple_backup_suffix == 0) {
 113                 unlink(orig);
 114                 return 0;
 115         }
 116         orig_device = filestat.st_dev;
 117         orig_inode = filestat.st_ino;
 118
 119         if (origprae) {
 120                 if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
 121                     strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
 122                         fatal("filename %s too long for buffer\n", origprae);
 123         } else {
 124                 if ((s = find_backup_file_name(orig)) == NULL)
 125                         fatal("out of memory\n");
 126                 if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
 127                         fatal("filename %s too long for buffer\n", s);
 128                 free(s);
 129         }
 130
 131         if ((simplename = strrchr(bakname, '/')) != NULL)
 132                 simplename = simplename + 1;
 133         else
 134                 simplename = bakname;
 135
 136         /*
 137          * Find a backup name that is not the same file. Change the
 138          * first lowercase char into uppercase; if that isn't
 139          * sufficient, chop off the first char and try again.
 140          */
 141         while (stat(bakname, &filestat) == 0 &&
 142             orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
 143                 /* Skip initial non-lowercase chars.  */
 144                 for (s = simplename; *s && !islower((unsigned char)*s); s++)
 145                         ;
 146                 if (*s)
 147                         *s = toupper((unsigned char)*s);
 148                 else
 149                         memmove(simplename, simplename + 1,
 150                             strlen(simplename + 1) + 1);
 151         }
 152 #ifdef DEBUGGING
 153         if (debug & 4)
 154                 say("Moving %s to %s.\n", orig, bakname);
 155 #endif
 156         if (rename(orig, bakname) < 0) {
 157                 if (errno != EXDEV || copy_file(orig, bakname) < 0)
 158                         return -1;
 159         }
 160         return 0;
 161 }
 162
 163 /*
 164  * Copy a file.
 165  */
 166 int
 167 copy_file(const char *from, const char *to)
 168 {
 169         int     tofd, fromfd;
 170         ssize_t i;
 171
 172         tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 173         if (tofd < 0)
 174                 return -1;
 175         fromfd = open(from, O_RDONLY, 0);
 176         if (fromfd < 0)
 177                 pfatal("internal error, can't reopen %s", from);
 178         while ((i = read(fromfd, buf, buf_len)) > 0)
 179                 if (write(tofd, buf, i) != i)
 180                         pfatal("write to %s failed", to);
 181         close(fromfd);
 182         close(tofd);
 183         return 0;
 184 }
 185
 186 /*
 187  * Allocate a unique area for a string.
 188  */
 189 char *
 190 savestr(const char *s)
 191 {
 192         char    *rv;
 193
 194         if (!s)
 195                 s = "Oops";
 196         rv = strdup(s);
 197         if (rv == NULL) {
 198                 if (using_plan_a)
 199                         out_of_mem = true;
 200                 else
 201                         fatal("out of memory\n");
 202         }
 203         return rv;
 204 }
 205
 206 /*
 207  * Vanilla terminal output (buffered).
 208  */
 209 void
 210 say(const char *fmt, ...)
 211 {
 212         va_list ap;
 213
 214         va_start(ap, fmt);
 215         vfprintf(stderr, fmt, ap);
 216         va_end(ap);
 217         fflush(stderr);
 218 }
 219
 220 /*
 221  * Terminal output, pun intended.
 222  */
 223 void
 224 fatal(const char *fmt, ...)
 225 {
 226         va_list ap;
 227
 228         va_start(ap, fmt);
 229         fprintf(stderr, "patch: **** ");
 230         vfprintf(stderr, fmt, ap);
 231         va_end(ap);
 232         my_exit(2);
 233 }
 234
 235 /*
 236  * Say something from patch, something from the system, then silence . . .
 237  */
 238 void
 239 pfatal(const char *fmt, ...)
 240 {
 241         va_list ap;
 242         int     errnum = errno;
 243
 244         fprintf(stderr, "patch: **** ");
 245         va_start(ap, fmt);
 246         vfprintf(stderr, fmt, ap);
 247         va_end(ap);
 248         fprintf(stderr, ": %s\n", strerror(errnum));
 249         my_exit(2);
 250 }
 251
 252 /*
 253  * Get a response from the user via /dev/tty
 254  */
 255 void
 256 ask(const char *fmt, ...)
 257 {
 258         va_list ap;
 259         ssize_t nr = 0;
 260         static  int ttyfd = -1;
 261
 262         va_start(ap, fmt);
 263         vfprintf(stdout, fmt, ap);
 264         va_end(ap);
 265         fflush(stdout);
 266         if (ttyfd < 0)
 267                 ttyfd = open(_PATH_TTY, O_RDONLY);
 268         if (ttyfd >= 0) {
 269                 if ((nr = read(ttyfd, buf, buf_len)) > 0 &&
 270                     buf[nr - 1] == '\n')
 271                         buf[nr - 1] = '\0';
 272         }
 273         if (ttyfd < 0 || nr <= 0) {
 274                 /* no tty or error reading, pretend user entered 'return' */
 275                 putchar('\n');
 276                 buf[0] = '\0';
 277         }
 278 }
 279
 280 /*
 281  * How to handle certain events when not in a critical region.
 282  */
 283 void
 284 set_signals(int reset)
 285 {
 286         static sig_t    hupval, intval;
 287
 288         if (!reset) {
 289                 hupval = signal(SIGHUP, SIG_IGN);
 290                 if (hupval != SIG_IGN)
 291                         hupval = my_exit;
 292                 intval = signal(SIGINT, SIG_IGN);
 293                 if (intval != SIG_IGN)
 294                         intval = my_exit;
 295         }
 296         signal(SIGHUP, hupval);
 297         signal(SIGINT, intval);
 298 }
 299
 300 /*
 301  * How to handle certain events when in a critical region.
 302  */
 303 void
 304 ignore_signals(void)
 305 {
 306         signal(SIGHUP, SIG_IGN);
 307         signal(SIGINT, SIG_IGN);
 308 }
 309
 310 /*
 311  * Make sure we'll have the directories to create a file. If `striplast' is
 312  * true, ignore the last element of `filename'.
 313  */
 314
 315 void
 316 makedirs(const char *filename, bool striplast)
 317 {
 318         char    *tmpbuf;
 319
 320         if ((tmpbuf = strdup(filename)) == NULL)
 321                 fatal("out of memory\n");
 322
 323         if (striplast) {
 324                 char    *s = strrchr(tmpbuf, '/');
 325                 if (s == NULL)
 326                         return; /* nothing to be done */
 327                 *s = '\0';
 328         }
 329         if (mkpath(tmpbuf) != 0)
 330                 pfatal("creation of %s failed", tmpbuf);
 331         free(tmpbuf);
 332 }
 333
 334 /*
 335  * Make filenames more reasonable.
 336  */
 337 char *
 338 fetchname(const char *at, bool *exists, int strip_leading)
 339 {
 340         char            *fullname, *name, *t;
 341         int             sleading, tab;
 342         struct stat     filestat;
 343
 344         if (at == NULL || *at == '\0')
 345                 return NULL;
 346         while (isspace((unsigned char)*at))
 347                 at++;
 348 #ifdef DEBUGGING
 349         if (debug & 128)
 350                 say("fetchname %s %d\n", at, strip_leading);
 351 #endif
 352         /* So files can be created by diffing against /dev/null.  */
 353         if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1))
 354                 return NULL;
 355         name = fullname = t = savestr(at);
 356
 357         tab = strchr(t, '\t') != NULL;
 358         /* Strip off up to `strip_leading' path components and NUL terminate. */
 359         for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
 360             !isspace((unsigned char)*t)); t++) {
 361                 if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
 362                         if (--sleading >= 0)
 363                                 name = t + 1;
 364         }
 365         *t = '\0';
 366
 367         /*
 368          * If no -p option was given (957 is the default value!), we were
 369          * given a relative pathname, and the leading directories that we
 370          * just stripped off all exist, put them back on.
 371          */
 372         if (strip_leading == 957 && name != fullname && *fullname != '/') {
 373                 name[-1] = '\0';
 374                 if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)) {
 375                         name[-1] = '/';
 376                         name = fullname;
 377                 }
 378         }
 379         name = savestr(name);
 380         free(fullname);
 381
 382         *exists = stat(name, &filestat) == 0;
 383         return name;
 384 }
 385
 386 /*
 387  * Takes the name returned by fetchname and looks in RCS/SCCS directories
 388  * for a checked in version.
 389  */
 390 char *
 391 checked_in(char *file)
 392 {
 393         char            *filebase, *filedir, tmpbuf[MAXPATHLEN];
 394         struct stat     filestat;
 395
 396         filebase = basename(file);
 397         filedir = dirname(file);
 398
 399 #define try(f, a1, a2, a3) \
 400 (snprintf(tmpbuf, sizeof tmpbuf, f, a1, a2, a3), stat(tmpbuf, &filestat) == 0)
 401
 402         if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
 403             try("%s/RCS/%s%s", filedir, filebase, "") ||
 404             try("%s/%s%s", filedir, filebase, RCSSUFFIX) ||
 405             try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
 406             try("%s/%s%s", filedir, SCCSPREFIX, filebase))
 407                 return file;
 408
 409         return NULL;
 410 }
 411
 412 void
 413 version(void)
 414 {
 415         fprintf(stderr, "Patch version 2.0-12u8-OpenBSD\n");
 416         my_exit(EXIT_SUCCESS);
 417 }
 418
 419 /*
 420  * Exit with cleanup.
 421  */
 422 void
 423 my_exit(int status)
 424 {
 425         unlink(TMPINNAME);
 426         if (!toutkeep)
 427                 unlink(TMPOUTNAME);
 428         if (!trejkeep)
 429                 unlink(TMPREJNAME);
 430         unlink(TMPPATNAME);
 431         exit(status);
 432 }