lib-src/b2m.c

   1 /*
   2  * b2m - a filter for Babyl -> Unix mail files
   3  * The copyright on this file has been disclaimed.
   4  *
   5  * usage:       b2m < babyl > mailbox
   6  *
   7  * I find this useful whenever I have to use a
   8  * system which - shock horror! - doesn't run
   9  * GNU Emacs. At least now I can read all my
  10  * GNU Emacs Babyl format mail files!
  11  *
  12  * it's not much but it's free!
  13  *
  14  *   Ed Wilkinson
  15  *   E.Wilkinson@massey.ac.nz
  16  *   Mon Nov 7 15:54:06 PDT 1988
  17  */
  18
  19 /* Made conformant to the GNU coding standards January, 1995
  20    by Francesco Potorti` <pot@cnuce.cnr.it>. */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 /* On some systems, Emacs defines static as nothing for the sake
  25    of unexec.  We don't want that here since we don't use unexec. */
  26 #undef static
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <time.h>
  31 #include <sys/types.h>
  32 #include <getopt.h>
  33 #ifdef MSDOS
  34 #include <fcntl.h>
  35 #endif
  36
  37 #undef TRUE
  38 #define TRUE    1
  39 #undef FALSE
  40 #define FALSE   0
  41
  42 #define streq(s,t)      (strcmp (s, t) == 0)
  43 #define strneq(s,t,n)   (strncmp (s, t, n) == 0)
  44
  45 typedef int logical;
  46
  47 #define TM_YEAR_BASE 1900
  48
  49 /* Nonzero if TM_YEAR is a struct tm's tm_year value that causes
  50    asctime to have well-defined behavior.  */
  51 #ifndef TM_YEAR_IN_ASCTIME_RANGE
  52 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) \
  53     (1000 - TM_YEAR_BASE <= (tm_year) && (tm_year) <= 9999 - TM_YEAR_BASE)
  54 #endif
  55
  56 /*
  57  * A `struct linebuffer' is a structure which holds a line of text.
  58  * `readline' reads a line from a stream into a linebuffer and works
  59  * regardless of the length of the line.
  60  */
  61 struct linebuffer
  62 {
  63   long size;
  64   char *buffer;
  65 };
  66
  67 extern char *strtok(char *, const char *);
  68
  69 long *xmalloc (unsigned int size);
  70 long *xrealloc (char *ptr, unsigned int size);
  71 char *concat (const char *s1, const char *s2, const char *s3);
  72 long readline (struct linebuffer *linebuffer, register FILE *stream);
  73 void fatal (const char *message) NO_RETURN;
  74
  75 /*
  76  * xnew -- allocate storage.  SYNOPSIS: Type *xnew (int n, Type);
  77  */
  78 #define xnew(n, Type)   ((Type *) xmalloc ((n) * sizeof (Type)))
  79
  80
  81
  82 char *progname;
  83
  84 struct option longopts[] =
  85 {
  86   { "help",                     no_argument,       NULL,     'h'   },
  87   { "version",                  no_argument,       NULL,     'V'   },
  88   { 0 }
  89 };
  90
  91 extern int optind;
  92
  93 int
  94 main (int argc, char **argv)
  95 {
  96   logical labels_saved, printing, header, first, last_was_blank_line;
  97   time_t ltoday;
  98   struct tm *tm;
  99   char *labels, *p, *today;
 100   struct linebuffer data;
 101
 102 #ifdef MSDOS
 103   _fmode = O_BINARY;            /* all of files are treated as binary files */
 104 #if __DJGPP__ > 1
 105   if (!isatty (fileno (stdout)))
 106     setmode (fileno (stdout), O_BINARY);
 107   if (!isatty (fileno (stdin)))
 108     setmode (fileno (stdin), O_BINARY);
 109 #else /* not __DJGPP__ > 1 */
 110   (stdout)->_flag &= ~_IOTEXT;
 111   (stdin)->_flag &= ~_IOTEXT;
 112 #endif /* not __DJGPP__ > 1 */
 113 #endif
 114   progname = argv[0];
 115
 116   while (1)
 117     {
 118       int opt = getopt_long (argc, argv, "hV", longopts, 0);
 119       if (opt == EOF)
 120         break;
 121
 122       switch (opt)
 123         {
 124         case 'V':
 125           printf ("%s (GNU Emacs %s)\n", "b2m", VERSION);
 126           puts ("b2m is in the public domain.");
 127           exit (EXIT_SUCCESS);
 128
 129         case 'h':
 130           fprintf (stderr, "Usage: %s <babylmailbox >unixmailbox\n", progname);
 131           exit (EXIT_SUCCESS);
 132         }
 133     }
 134
 135   if (optind != argc)
 136     {
 137       fprintf (stderr, "Usage: %s <babylmailbox >unixmailbox\n", progname);
 138       exit (EXIT_SUCCESS);
 139     }
 140
 141   labels_saved = printing = header = last_was_blank_line = FALSE;
 142   first = TRUE;
 143   ltoday = time (0);
 144   /* Convert to a string, checking for out-of-range time stamps.
 145      Don't use 'ctime', as that might dump core if the hardware clock
 146      is set to a bizarre value.  */
 147   tm = localtime (&ltoday);
 148   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)
 149          && (today = asctime (tm))))
 150     fatal ("current time is out of range");
 151   data.size = 200;
 152   data.buffer = xnew (200, char);
 153
 154   if (readline (&data, stdin) == 0
 155       || !strneq (data.buffer, "BABYL OPTIONS:", 14))
 156     fatal ("standard input is not a Babyl mailfile.");
 157
 158   while (readline (&data, stdin) > 0)
 159     {
 160       if (streq (data.buffer, "*** EOOH ***") && !printing)
 161         {
 162           printing = header = TRUE;
 163           printf ("From \"Babyl to mail by %s\" %s", progname, today);
 164           continue;
 165         }
 166
 167       if (data.buffer[0] == '\037')
 168         {
 169           if (data.buffer[1] == '\0')
 170             continue;
 171           else if (data.buffer[1] == '\f')
 172             {
 173               static char babyl[] = "X-Babyl-Labels: ";
 174               if (first)
 175                 first = FALSE;
 176               else if (! last_was_blank_line)
 177                 puts("");
 178               /* Save labels. */
 179               readline (&data, stdin);
 180               p = strtok (data.buffer, " ,\r\n\t");
 181               labels = babyl;
 182
 183               while ((p = strtok (NULL, " ,\r\n\t")))
 184                 labels = concat (labels, p, ", ");
 185
 186               p = &labels[strlen (labels) - 2];
 187               if (*p == ',')
 188                 *p = '\0';
 189               printing = header = FALSE;
 190               labels_saved = TRUE;
 191               continue;
 192             }
 193         }
 194
 195       if ((data.buffer[0] == '\0') && header)
 196         {
 197           header = FALSE;
 198           if (labels_saved)
 199             puts (labels);
 200         }
 201
 202       if (printing)
 203         {
 204           puts (data.buffer);
 205           if (data.buffer[0] == '\0')
 206             last_was_blank_line = TRUE;
 207           else
 208             last_was_blank_line = FALSE;
 209         }
 210     }
 211
 212   return EXIT_SUCCESS;
 213 }
 214
 215
 216
 217 /*
 218  * Return a newly-allocated string whose contents
 219  * concatenate those of s1, s2, s3.
 220  */
 221 char *
 222 concat (const char *s1, const char *s2, const char *s3)
 223 {
 224   int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
 225   char *result = xnew (len1 + len2 + len3 + 1, char);
 226
 227   strcpy (result, s1);
 228   strcpy (result + len1, s2);
 229   strcpy (result + len1 + len2, s3);
 230   result[len1 + len2 + len3] = '\0';
 231
 232   return result;
 233 }
 234
 235 /*
 236  * Read a line of text from `stream' into `linebuffer'.
 237  * Return the number of characters read from `stream',
 238  * which is the length of the line including the newline, if any.
 239  */
 240 long
 241 readline (struct linebuffer *linebuffer, register FILE *stream)
 242 {
 243   char *buffer = linebuffer->buffer;
 244   register char *p = linebuffer->buffer;
 245   register char *pend;
 246   int chars_deleted;
 247
 248   pend = p + linebuffer->size;  /* Separate to avoid 386/IX compiler bug.  */
 249
 250   while (1)
 251     {
 252       register int c = getc (stream);
 253       if (p == pend)
 254         {
 255           linebuffer->size *= 2;
 256           buffer = (char *) xrealloc (buffer, linebuffer->size);
 257           p += buffer - linebuffer->buffer;
 258           pend = buffer + linebuffer->size;
 259           linebuffer->buffer = buffer;
 260         }
 261       if (c == EOF)
 262         {
 263           *p = '\0';
 264           chars_deleted = 0;
 265           break;
 266         }
 267       if (c == '\n')
 268         {
 269           if (p > buffer && p[-1] == '\r')
 270             {
 271               *--p = '\0';
 272               chars_deleted = 2;
 273             }
 274           else
 275             {
 276               *p = '\0';
 277               chars_deleted = 1;
 278             }
 279           break;
 280         }
 281       *p++ = c;
 282     }
 283
 284   return (p - buffer + chars_deleted);
 285 }
 286
 287 /*
 288  * Like malloc but get fatal error if memory is exhausted.
 289  */
 290 long *
 291 xmalloc (unsigned int size)
 292 {
 293   long *result = (long *) malloc (size);
 294   if (result == NULL)
 295     fatal ("virtual memory exhausted");
 296   return result;
 297 }
 298
 299 long *
 300 xrealloc (char *ptr, unsigned int size)
 301 {
 302   long *result = (long *) realloc (ptr, size);
 303   if (result == NULL)
 304     fatal ("virtual memory exhausted");
 305   return result;
 306 }
 307
 308 void
 309 fatal (const char *message)
 310 {
 311   fprintf (stderr, "%s: %s\n", progname, message);
 312   exit (EXIT_FAILURE);
 313 }
 314
 315 /* arch-tag: 5a3ad2af-a802-408f-83cc-e7cf5e98653e
 316    (do not change this comment) */
 317
 318 /* b2m.c ends here */