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;
  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 = FALSE;
 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               /* Save labels. */
 174               readline (&data, stdin);
 175               p = strtok (data.buffer, " ,\r\n\t");
 176               labels = "X-Babyl-Labels: ";
 177
 178               while ((p = strtok (NULL, " ,\r\n\t")))
 179                 labels = concat (labels, p, ", ");
 180
 181               p = &labels[strlen (labels) - 2];
 182               if (*p == ',')
 183                 *p = '\0';
 184               printing = header = FALSE;
 185               labels_saved = TRUE;
 186               continue;
 187             }
 188         }
 189
 190       if ((data.buffer[0] == '\0') && header)
 191         {
 192           header = FALSE;
 193           if (labels_saved)
 194             puts (labels);
 195         }
 196
 197       if (printing)
 198         puts (data.buffer);
 199     }
 200
 201   return EXIT_SUCCESS;
 202 }
 203
 204
 205
 206 /*
 207  * Return a newly-allocated string whose contents
 208  * concatenate those of s1, s2, s3.
 209  */
 210 char *
 211 concat (s1, s2, s3)
 212      char *s1, *s2, *s3;
 213 {
 214   int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
 215   char *result = xnew (len1 + len2 + len3 + 1, char);
 216
 217   strcpy (result, s1);
 218   strcpy (result + len1, s2);
 219   strcpy (result + len1 + len2, s3);
 220   result[len1 + len2 + len3] = '\0';
 221
 222   return result;
 223 }
 224
 225 /*
 226  * Read a line of text from `stream' into `linebuffer'.
 227  * Return the number of characters read from `stream',
 228  * which is the length of the line including the newline, if any.
 229  */
 230 long
 231 readline (linebuffer, stream)
 232      struct linebuffer *linebuffer;
 233      register FILE *stream;
 234 {
 235   char *buffer = linebuffer->buffer;
 236   register char *p = linebuffer->buffer;
 237   register char *pend;
 238   int chars_deleted;
 239
 240   pend = p + linebuffer->size;  /* Separate to avoid 386/IX compiler bug.  */
 241
 242   while (1)
 243     {
 244       register int c = getc (stream);
 245       if (p == pend)
 246         {
 247           linebuffer->size *= 2;
 248           buffer = (char *) xrealloc (buffer, linebuffer->size);
 249           p += buffer - linebuffer->buffer;
 250           pend = buffer + linebuffer->size;
 251           linebuffer->buffer = buffer;
 252         }
 253       if (c == EOF)
 254         {
 255           *p = '\0';
 256           chars_deleted = 0;
 257           break;
 258         }
 259       if (c == '\n')
 260         {
 261           if (p > buffer && p[-1] == '\r')
 262             {
 263               *--p = '\0';
 264               chars_deleted = 2;
 265             }
 266           else
 267             {
 268               *p = '\0';
 269               chars_deleted = 1;
 270             }
 271           break;
 272         }
 273       *p++ = c;
 274     }
 275
 276   return (p - buffer + chars_deleted);
 277 }
 278
 279 /*
 280  * Like malloc but get fatal error if memory is exhausted.
 281  */
 282 long *
 283 xmalloc (size)
 284      unsigned int size;
 285 {
 286   long *result = (long *) malloc (size);
 287   if (result == NULL)
 288     fatal ("virtual memory exhausted");
 289   return result;
 290 }
 291
 292 long *
 293 xrealloc (ptr, size)
 294      char *ptr;
 295      unsigned int size;
 296 {
 297   long *result = (long *) realloc (ptr, size);
 298   if (result == NULL)
 299     fatal ("virtual memory exhausted");
 300   return result;
 301 }
 302
 303 void
 304 fatal (message)
 305      char *message;
 306 {
 307   fprintf (stderr, "%s: %s\n", progname, message);
 308   exit (EXIT_FAILURE);
 309 }
 310
 311 /* arch-tag: 5a3ad2af-a802-408f-83cc-e7cf5e98653e
 312    (do not change this comment) */
 313
 314 /* b2m.c ends here */