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