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();
  68
  69 long *xmalloc (), *xrealloc ();
  70 char *concat ();
  71 long readline ();
  72 void fatal ();
  73
  74 /*
  75  * xnew -- allocate storage.  SYNOPSIS: Type *xnew (int n, Type);
  76  */
  77 #define xnew(n, Type)   ((Type *) xmalloc ((n) * sizeof (Type)))
  78
  79
  80
  81 char *progname;
  82
  83 struct option longopts[] =
  84 {
  85   { "help",                     no_argument,       NULL,     'h'   },
  86   { "version",                  no_argument,       NULL,     'V'   },
  87   { 0 }
  88 };
  89
  90 extern int optind;
  91
  92 int
  93 main (argc, argv)
  94      int argc;
  95      char **argv;
  96 {
  97   logical labels_saved, printing, header, first, last_was_blank_line;
  98   time_t ltoday;
  99   struct tm *tm;
 100   char *labels, *p, *today;
 101   struct linebuffer data;
 102
 103 #ifdef MSDOS
 104   _fmode = O_BINARY;            /* all of files are treated as binary files */
 105 #if __DJGPP__ > 1
 106   if (!isatty (fileno (stdout)))
 107     setmode (fileno (stdout), O_BINARY);
 108   if (!isatty (fileno (stdin)))
 109     setmode (fileno (stdin), O_BINARY);
 110 #else /* not __DJGPP__ > 1 */
 111   (stdout)->_flag &= ~_IOTEXT;
 112   (stdin)->_flag &= ~_IOTEXT;
 113 #endif /* not __DJGPP__ > 1 */
 114 #endif
 115   progname = argv[0];
 116
 117   while (1)
 118     {
 119       int opt = getopt_long (argc, argv, "hV", longopts, 0);
 120       if (opt == EOF)
 121         break;
 122
 123       switch (opt)
 124         {
 125         case 'V':
 126           printf ("%s (GNU Emacs %s)\n", "b2m", VERSION);
 127           puts ("b2m is in the public domain.");
 128           exit (EXIT_SUCCESS);
 129
 130         case 'h':
 131           fprintf (stderr, "Usage: %s <babylmailbox >unixmailbox\n", progname);
 132           exit (EXIT_SUCCESS);
 133         }
 134     }
 135
 136   if (optind != argc)
 137     {
 138       fprintf (stderr, "Usage: %s <babylmailbox >unixmailbox\n", progname);
 139       exit (EXIT_SUCCESS);
 140     }
 141
 142   labels_saved = printing = header = last_was_blank_line = FALSE;
 143   first = TRUE;
 144   ltoday = time (0);
 145   /* Convert to a string, checking for out-of-range time stamps.
 146      Don't use 'ctime', as that might dump core if the hardware clock
 147      is set to a bizarre value.  */
 148   tm = localtime (&ltoday);
 149   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)
 150          && (today = asctime (tm))))
 151     fatal ("current time is out of range");
 152   data.size = 200;
 153   data.buffer = xnew (200, char);
 154
 155   if (readline (&data, stdin) == 0
 156       || !strneq (data.buffer, "BABYL OPTIONS:", 14))
 157     fatal ("standard input is not a Babyl mailfile.");
 158
 159   while (readline (&data, stdin) > 0)
 160     {
 161       if (streq (data.buffer, "*** EOOH ***") && !printing)
 162         {
 163           printing = header = TRUE;
 164           printf ("From \"Babyl to mail by %s\" %s", progname, today);
 165           continue;
 166         }
 167
 168       if (data.buffer[0] == '\037')
 169         {
 170           if (data.buffer[1] == '\0')
 171             continue;
 172           else if (data.buffer[1] == '\f')
 173             {
 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 = "X-Babyl-Labels: ";
 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 (s1, s2, s3)
 223      char *s1, *s2, *s3;
 224 {
 225   int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
 226   char *result = xnew (len1 + len2 + len3 + 1, char);
 227
 228   strcpy (result, s1);
 229   strcpy (result + len1, s2);
 230   strcpy (result + len1 + len2, s3);
 231   result[len1 + len2 + len3] = '\0';
 232
 233   return result;
 234 }
 235
 236 /*
 237  * Read a line of text from `stream' into `linebuffer'.
 238  * Return the number of characters read from `stream',
 239  * which is the length of the line including the newline, if any.
 240  */
 241 long
 242 readline (linebuffer, stream)
 243      struct linebuffer *linebuffer;
 244      register FILE *stream;
 245 {
 246   char *buffer = linebuffer->buffer;
 247   register char *p = linebuffer->buffer;
 248   register char *pend;
 249   int chars_deleted;
 250
 251   pend = p + linebuffer->size;  /* Separate to avoid 386/IX compiler bug.  */
 252
 253   while (1)
 254     {
 255       register int c = getc (stream);
 256       if (p == pend)
 257         {
 258           linebuffer->size *= 2;
 259           buffer = (char *) xrealloc (buffer, linebuffer->size);
 260           p += buffer - linebuffer->buffer;
 261           pend = buffer + linebuffer->size;
 262           linebuffer->buffer = buffer;
 263         }
 264       if (c == EOF)
 265         {
 266           *p = '\0';
 267           chars_deleted = 0;
 268           break;
 269         }
 270       if (c == '\n')
 271         {
 272           if (p > buffer && p[-1] == '\r')
 273             {
 274               *--p = '\0';
 275               chars_deleted = 2;
 276             }
 277           else
 278             {
 279               *p = '\0';
 280               chars_deleted = 1;
 281             }
 282           break;
 283         }
 284       *p++ = c;
 285     }
 286
 287   return (p - buffer + chars_deleted);
 288 }
 289
 290 /*
 291  * Like malloc but get fatal error if memory is exhausted.
 292  */
 293 long *
 294 xmalloc (size)
 295      unsigned int size;
 296 {
 297   long *result = (long *) malloc (size);
 298   if (result == NULL)
 299     fatal ("virtual memory exhausted");
 300   return result;
 301 }
 302
 303 long *
 304 xrealloc (ptr, size)
 305      char *ptr;
 306      unsigned int size;
 307 {
 308   long *result = (long *) realloc (ptr, size);
 309   if (result == NULL)
 310     fatal ("virtual memory exhausted");
 311   return result;
 312 }
 313
 314 void
 315 fatal (message)
 316      char *message;
 317 {
 318   fprintf (stderr, "%s: %s\n", progname, message);
 319   exit (EXIT_FAILURE);
 320 }
 321
 322 /* arch-tag: 5a3ad2af-a802-408f-83cc-e7cf5e98653e
 323    (do not change this comment) */
 324
 325 /* b2m.c ends here */