diplodocus.org Git - nmh/blob - sbr/utils.c

   1 /* utils.c -- various utility routines
   2  *
   3  * This code is Copyright (c) 2006, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include "h/mh.h"
   9 #include "read_yes_or_no_if_tty.h"
  10 #include "concat.h"
  11 #include "r1bindex.h"
  12 #include "context_foil.h"
  13 #include "context_replace.h"
  14 #include "context_read.h"
  15 #include "context_find.h"
  16 #include "print_help.h"
  17 #include "error.h"
  18 #include "h/utils.h"
  19 #include "h/signals.h"
  20 #include "m_mktemp.h"
  21 #include "makedir.h"
  22 #include <fcntl.h>
  23 #include <limits.h>
  24 #include "read_line.h"
  25
  26 extern char *mhdocdir;
  27
  28 /* plurals gives the letter ess to indicate a plural noun, or an empty
  29  * string as plurals+1 for the singular noun.  Used by the PLURALS
  30  * macro. */
  31 const char plurals[] = "s";
  32
  33 /*
  34  * We allocate space for messages (msgs array)
  35  * this number of elements at a time.
  36  */
  37 #define MAXMSGS 256
  38
  39 /* Call malloc(3), exiting on NULL return. */
  40 void *
  41 mh_xmalloc(size_t size)
  42 {
  43     void *p;
  44
  45     if (size == 0)
  46         size = 1; /* Some mallocs don't like 0. */
  47     p = malloc(size);
  48     if (!p)
  49         die("malloc failed, size wanted: %zu", size);
  50
  51     return p;
  52 }
  53
  54 /* Call realloc(3), exiting on NULL return. */
  55 void *
  56 mh_xrealloc(void *ptr, size_t size)
  57 {
  58     void *new;
  59
  60     /* Copy POSIX behaviour, coping with non-POSIX systems. */
  61     if (size == 0) {
  62         free(ptr);
  63         return mh_xmalloc(1); /* Get a unique pointer. */
  64     }
  65     if (!ptr)
  66         return mh_xmalloc(size);
  67
  68     new = realloc(ptr, size);
  69     if (!new)
  70         die("realloc failed, size wanted: %zu", size);
  71
  72     return new;
  73 }
  74
  75 /* Call calloc(3), exiting on NULL return. */
  76 void *
  77 mh_xcalloc(size_t nelem, size_t elsize)
  78 {
  79     void *p;
  80
  81     if (!nelem || !elsize)
  82         return mh_xmalloc(1); /* Get a unique pointer. */
  83
  84     p = calloc(nelem, elsize);
  85     if (!p)
  86         die("calloc failed, size wanted: %zu * %zu", nelem, elsize);
  87
  88     return p;
  89 }
  90
  91 /* Duplicate a NUL-terminated string, exit on failure. */
  92 char *
  93 mh_xstrdup(const char *src)
  94 {
  95     size_t n;
  96     char *dest;
  97
  98     n = strlen(src) + 1; /* Ignore possibility of overflow. */
  99     dest = mh_xmalloc(n);
 100     memcpy(dest, src, n);
 101
 102     return dest;
 103 }
 104
 105 /*
 106  * Return the present working directory, if the current directory does not
 107  * exist, or is too long, make / the pwd.
 108  */
 109 char *
 110 pwd(void)
 111 {
 112     char *cp;
 113     static char curwd[PATH_MAX];
 114
 115     if (!getcwd (curwd, PATH_MAX)) {
 116         inform("unable to determine working directory, continuing...");
 117         if (!mypath || !*mypath
 118                 || (strcpy (curwd, mypath), chdir (curwd)) == -1) {
 119             strcpy (curwd, "/");
 120             if (chdir (curwd) < 0) {
 121                 advise (curwd, "chdir");
 122             }
 123         }
 124         return curwd;
 125     }
 126
 127     if ((cp = curwd + strlen (curwd) - 1) > curwd && *cp == '/')
 128         *cp = '\0';
 129
 130     return curwd;
 131 }
 132
 133 /* add returns a newly malloc'd string, exiting on failure.  The order
 134  * of the parameters is unusual.  A NULL parameter is treated as an
 135  * empty string.  s1 is free'd.  Use mh_xstrdup(s) rather than add(s,
 136  * NULL), with FENDNULL() if s might be NULL.
 137  *
 138  *     add(NULL, NULL) -> ""
 139  *     add(NULL, "foo") -> "foo"
 140  *     add("bar", NULL) -> "bar"
 141  *     add("bar", "foo") -> "foobar"
 142  */
 143 char *
 144 add (const char *s2, char *s1)
 145 {
 146     char *cp;
 147     size_t len1 = 0, len2 = 0;
 148
 149     if (s1)
 150         len1 = strlen (s1);
 151     if (s2)
 152         len2 = strlen (s2);
 153
 154     cp = mh_xmalloc (len1 + len2 + 1);
 155
 156     /* Copy s1 and free it */
 157     if (s1) {
 158         memcpy (cp, s1, len1);
 159         free (s1);
 160     }
 161
 162     /* Copy s2 */
 163     if (s2)
 164         memcpy (cp + len1, s2, len2);
 165
 166     /* Now NULL terminate the string */
 167     cp[len1 + len2] = '\0';
 168
 169     return cp;
 170 }
 171
 172 /*
 173  * addlist
 174  *      Append an item to a comma separated list
 175  */
 176 char *
 177 addlist (char *list, const char *item)
 178 {
 179     if (list)
 180         list = add (", ", list);
 181
 182     return add (item, list);
 183 }
 184
 185 /*
 186  * folder_exists
 187  *      Check to see if a folder exists.
 188  */
 189 int
 190 folder_exists(const char *folder)
 191 {
 192     struct stat st;
 193
 194     return stat(folder, &st) != -1;
 195 }
 196
 197 /*
 198  * create_folder
 199  *      Check to see if a folder exists, if not, prompt the user to create
 200  *      it.
 201  */
 202 void
 203 create_folder(char *folder, int autocreate, void (*done_callback)(int))
 204 {
 205     struct stat st;
 206     extern int errno;
 207     char *cp;
 208
 209     if (stat (folder, &st) == -1) {
 210         if (errno != ENOENT)
 211             adios (folder, "error on folder");
 212         if (autocreate == 0) {
 213             /* ask before creating folder */
 214             cp = concat ("Create folder \"", folder, "\"? ", NULL);
 215             if (!read_yes_or_no_if_tty (cp))
 216                 done_callback (1);
 217             free (cp);
 218         } else if (autocreate == -1) {
 219             /* do not create, so exit */
 220             done_callback (1);
 221         }
 222         if (!makedir (folder))
 223             die("unable to create folder %s", folder);
 224     }
 225 }
 226
 227 /*
 228  * num_digits
 229  *      Return the number of digits in a nonnegative integer.
 230  */
 231 int
 232 num_digits (int n)
 233 {
 234     int ndigits = 0;
 235
 236     /* Sanity check */
 237     if (n < 0)
 238         die("oops, num_digits called with negative value");
 239
 240     if (n == 0)
 241         return 1;
 242
 243     while (n) {
 244         n /= 10;
 245         ndigits++;
 246     }
 247
 248     return ndigits;
 249 }
 250
 251 /*
 252  * Append a message arg to an array of them, resizing it if necessary.
 253  * Really a simple vector-of-(char *) maintenance routine.
 254  */
 255 void
 256 app_msgarg(struct msgs_array *msgs, char *cp)
 257 {
 258         if(msgs->size >= msgs->max) {
 259                 msgs->max += MAXMSGS;
 260                 msgs->msgs = mh_xrealloc(msgs->msgs,
 261                         msgs->max * sizeof(*msgs->msgs));
 262         }
 263         msgs->msgs[msgs->size++] = cp;
 264 }
 265
 266 /*
 267  * Append a message number to an array of them, resizing it if necessary.
 268  * Like app_msgarg, but with a vector-of-ints instead.
 269  */
 270
 271 void
 272 app_msgnum(struct msgnum_array *msgs, int msgnum)
 273 {
 274         if (msgs->size >= msgs->max) {
 275                 msgs->max += MAXMSGS;
 276                 msgs->msgnums = mh_xrealloc(msgs->msgnums,
 277                         msgs->max * sizeof(*msgs->msgnums));
 278         }
 279         msgs->msgnums[msgs->size++] = msgnum;
 280 }
 281
 282
 283 /*
 284  * Finds first occurrence of str in buf.  buf is not a C string but a
 285  * byte array of length buflen.  str is a null-terminated C string.
 286  * find_str() does not modify buf but passes back a non-const char *
 287  * pointer so that the caller can modify it.
 288  */
 289 char *
 290 find_str (const char buf[], size_t buflen, const char *str)
 291 {
 292     const size_t len = strlen (str);
 293     size_t i;
 294
 295     for (i = 0; i + len <= buflen; ++i, ++buf) {
 296         if (! memcmp (buf, str, len)) return (char *) buf;
 297     }
 298
 299     return NULL;
 300 }
 301
 302
 303 /*
 304  * Finds last occurrence of str in buf.  buf is not a C string but a
 305  * byte array of length buflen.  str is a null-terminated C string.
 306  * find_str() does not modify buf but passes back a non-const char *
 307  * pointer so that the caller can modify it.
 308  */
 309 char *
 310 rfind_str (const char buf[], size_t buflen, const char *str)
 311 {
 312     const size_t len = strlen (str);
 313     size_t i;
 314
 315     for (i = 0, buf += buflen - len; i + len <= buflen; ++i, --buf) {
 316         if (! memcmp (buf, str, len)) return (char *) buf;
 317     }
 318
 319     return NULL;
 320 }
 321
 322
 323 /* POSIX doesn't have strcasestr() so emulate it. */
 324 char *
 325 nmh_strcasestr (const char *s1, const char *s2)
 326 {
 327     const size_t len = strlen (s2);
 328
 329     if (isupper ((unsigned char) s2[0])  ||  islower ((unsigned char)s2[0])) {
 330         char first[3];
 331         first[0] = (char) toupper ((unsigned char) s2[0]);
 332         first[1] = (char) tolower ((unsigned char) s2[0]);
 333         first[2] = '\0';
 334
 335         for (s1 = strpbrk (s1, first); s1; s1 = strpbrk (++s1, first)) {
 336             if (! strncasecmp (s1, s2, len)) return (char *) s1;
 337         }
 338     } else {
 339         for (s1 = strchr (s1, s2[0]); s1; s1 = strchr (++s1, s2[0])) {
 340             if (! strncasecmp (s1, s2, len)) return (char *) s1;
 341         }
 342     }
 343
 344     return NULL;
 345 }
 346
 347
 348 /* truncpy copies at most size - 1 chars from non-NULL src to non-NULL,
 349  * non-overlapping, dst, and ensures dst is NUL terminated.  If size is
 350  * zero then it aborts as dst cannot be NUL terminated.
 351  *
 352  * It's to be used when truncation is intended and correct, e.g.
 353  * reporting a possibly very long external string back to the user.  One
 354  * of its advantages over strncpy(3) is it doesn't pad in the common
 355  * case of no truncation. */
 356 void
 357 trunccpy(char *dst, const char *src, size_t size)
 358 {
 359     if (!size) {
 360         inform("trunccpy: zero-length destination: \"%.20s\"",
 361             src ? src : "null");
 362         abort();
 363     }
 364
 365     if (strnlen(src, size) < size) {
 366         strcpy(dst, src);
 367     } else {
 368         memcpy(dst, src, size - 1);
 369         dst[size - 1] = '\0';
 370     }
 371 }
 372
 373
 374 /* has_prefix returns true if non-NULL s starts with non-NULL prefix. */
 375 bool
 376 has_prefix(const char *s, const char *prefix)
 377 {
 378     while (*s && *s == *prefix) {
 379         s++;
 380         prefix++;
 381     }
 382
 383     return *prefix == '\0';
 384 }
 385
 386
 387 /* has_suffix returns true if non-NULL s ends with non-NULL suffix. */
 388 bool
 389 has_suffix(const char *s, const char *suffix)
 390 {
 391     size_t ls, lsuf;
 392
 393     ls = strlen(s);
 394     lsuf = strlen(suffix);
 395
 396     return lsuf <= ls && !strcmp(s + ls - lsuf, suffix);
 397 }
 398
 399
 400 /* has_suffix_c returns true if non-NULL string s ends with a c before the
 401  * terminating NUL. */
 402 bool
 403 has_suffix_c(const char *s, int c)
 404 {
 405     return *s && s[strlen(s) - 1] == c;
 406 }
 407
 408
 409 /* trim_suffix_c deletes c from the end of non-NULL string s if it's
 410  * present, shortening s by 1.  Only one instance of c is removed. */
 411 void
 412 trim_suffix_c(char *s, int c)
 413 {
 414     if (!*s)
 415         return;
 416
 417     s += strlen(s) - 1;
 418     if (*s == c)
 419         *s = '\0';
 420 }
 421
 422
 423 /* to_lower runs all of s through tolower(3). */
 424 void
 425 to_lower(char *s)
 426 {
 427     unsigned char *b;
 428
 429     for (b = (unsigned char *)s; (*b = tolower(*b)); b++)
 430         ;
 431 }
 432
 433
 434 /* to_upper runs all of s through toupper(3). */
 435 void
 436 to_upper(char *s)
 437 {
 438     unsigned char *b;
 439
 440     for (b = (unsigned char *)s; (*b = toupper(*b)); b++)
 441         ;
 442 }
 443
 444
 445 int
 446 nmh_init(const char *argv0, bool read_context, bool check_version)
 447 {
 448     int status = OK;
 449     char *locale;
 450
 451     invo_name = r1bindex ((char *) argv0, '/');
 452
 453     if (setup_signal_handlers()) {
 454         admonish("sigaction", "unable to set up signal handlers");
 455     }
 456
 457     /* POSIX atexit() does not define any error conditions. */
 458     if (atexit(remove_registered_files_atexit)) {
 459         admonish("atexit", "unable to register atexit function");
 460     }
 461
 462     /* Read context, if supposed to. */
 463     if (read_context) {
 464         char *cp;
 465
 466         context_read();
 467
 468         bool allow_version_check = true;
 469         bool check_older_version = false;
 470         if (!check_version ||
 471             ((cp = context_find ("Welcome")) && strcasecmp (cp, "disable") == 0)) {
 472             allow_version_check = false;
 473         } else if ((cp = getenv ("MHCONTEXT")) != NULL && *cp != '\0') {
 474             /* Context file comes from $MHCONTEXT, so only print the message
 475                if the context file has an older version.  If it does, or if it
 476                doesn't have a version at all, update the version. */
 477             check_older_version = true;
 478         }
 479
 480         /* Check to see if the user is running a different (or older, if
 481            specified) version of nmh than they had run before, and notify them
 482            if so. */
 483         if (allow_version_check  &&  isatty (fileno (stdin))  &&
 484             isatty (fileno (stdout))  &&  isatty (fileno (stderr))) {
 485             if (nmh_version_changed (check_older_version)) {
 486                 printf ("==================================================="
 487                         "=====================\n");
 488                 printf ("Welcome to nmh version %s\n\n", VERSION);
 489                 printf ("See the release notes in %s/NEWS\n\n",
 490                          mhdocdir);
 491                 print_intro (stdout, 1);
 492                 printf ("\nThis message will not be repeated until "
 493                         "nmh is next updated.\n");
 494                 printf ("==================================================="
 495                         "=====================\n\n");
 496
 497                 fputs ("Press enter to continue: ", stdout);
 498                 (void) read_line ();
 499                 putchar ('\n');
 500             }
 501         }
 502     } else {
 503         if ((status = context_foil(NULL)) != OK) {
 504             advise("", "failed to create minimal profile/context");
 505         }
 506     }
 507
 508     /* Allow the user to set a locale in their profile.  Otherwise, use the
 509        "" string to pull it from their environment, see setlocale(3). */
 510     if ((locale = context_find ("locale")) == NULL) {
 511         locale = "";
 512     }
 513
 514     if (! setlocale (LC_ALL, locale)) {
 515         inform("setlocale failed, check your LC_ALL, LC_CTYPE, and LANG "
 516             "environment variables, continuing...");
 517     }
 518
 519     return status;
 520 }
 521
 522
 523 /*
 524  * Check stored version, and return 1 if out-of-date or non-existent.
 525  * Because the output of "mhparam version" is prefixed with "nmh-",
 526  * use that prefix here.
 527  */
 528 int
 529 nmh_version_changed (int older)
 530 {
 531     const char *const context_version = context_find("Version");
 532
 533     if (older) {
 534         /* Convert the version strings to floats and compare them.  This will
 535            break for versions with multiple decimal points, etc. */
 536         const float current_version = strtof (VERSION, NULL);
 537         const float old_version =
 538             context_version  &&  has_prefix(context_version, "nmh-")
 539             ?  strtof (context_version + 4, NULL)
 540             :  99999999;
 541
 542         if (context_version == NULL  ||  old_version < current_version) {
 543             context_replace ("Version", "nmh-" VERSION);
 544         }
 545
 546         return old_version < current_version;
 547     }
 548
 549     if (context_version == NULL  ||  strcmp(context_version, "nmh-" VERSION) != 0) {
 550         context_replace ("Version", "nmh-" VERSION);
 551         return 1;
 552     }
 553
 554     return 0;
 555 }
 556
 557
 558 /* contains8bit returns true if any byte from start onwards fails
 559  * isascii(3), i.e. is outside [0, 0x7f].  If start is NULL it returns
 560  * false.  Bytes are examined until a NUL byte, or, if end is not NULL,
 561  * whilst start is before end. */
 562 bool
 563 contains8bit(const char *start, const char *end)
 564 {
 565     const char *p;
 566     char c;
 567
 568     if (!start)
 569         return false;
 570
 571     p = start;
 572     if (end) {
 573         while (p < end && (c = (*p++)))
 574             if (!isascii((unsigned char)c))
 575                 return true;
 576     } else {
 577         while ((c = (*p++)))
 578             if (!isascii((unsigned char)c))
 579                 return true;
 580     }
 581
 582     return false;
 583 }
 584
 585
 586 /*
 587  * See if input has any 8-bit bytes.
 588  */
 589 int
 590 scan_input (int fd, int *eightbit)
 591 {
 592     int state;
 593     char buf[BUFSIZ];
 594
 595     *eightbit = 0;
 596     lseek(fd, 0, SEEK_SET);
 597
 598     while ((state = read (fd, buf, sizeof buf)) > 0) {
 599         if (contains8bit (buf, buf + state)) {
 600             *eightbit = 1;
 601             return OK;
 602         }
 603     }
 604
 605     return state == NOTOK  ?  NOTOK  :  OK;
 606 }
 607
 608
 609 /*
 610  * Convert an int to a char string.
 611  */
 612 char *
 613 m_str(int value)
 614 {
 615     return m_strn(value, 0);
 616 }
 617
 618
 619 /*
 620  * Convert an int to a char string, of limited width if > 0.
 621  */
 622 #define STR(s) #s
 623 /* SIZE(n) includes NUL.  n must just be digits, not an equation. */
 624 #define SIZE(n) (sizeof STR(n))
 625
 626 char *
 627 m_strn(int value, unsigned int width)
 628 {
 629     /* Need to include space for negative sign.  But don't use INT_MIN
 630        because it could be a macro that would fool SIZE(n). */
 631     static char buffer[SIZE(-INT_MAX)];
 632     const int num_chars = snprintf(buffer, sizeof buffer, "%d", value);
 633
 634     return num_chars > 0  &&  (width == 0 || (unsigned int) num_chars <= width)
 635         ? buffer
 636         : "?";
 637 }