lib-src/b2m.c

   1 /*
   2  * b2m - a filter for Babyl -> Unix mail files
   3  *
   4  * usage:       b2m < babyl > mailbox
   5  *
   6  * I find this useful whenever I have to use a
   7  * system which - shock horror! - doesn't run
   8  * Gnu emacs. At least now I can read all my
   9  * Gnumacs Babyl format mail files!
  10  *
  11  * it's not much but it's free!
  12  *
  13  *   Ed Wilkinson
  14  *   E.Wilkinson@massey.ac.nz
  15  *   Mon Nov 7 15:54:06 PDT 1988
  16  */
  17
  18 /* Made conformant to the GNU coding standards January, 1995
  19    by Francesco Potorti` <pot@cnuce.cnr.it>. */
  20
  21 #include <stdio.h>
  22 #include <time.h>
  23 #include <sys/types.h>
  24 #ifdef MSDOS
  25 #include <fcntl.h>
  26 #endif
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include <config.h>
  30 /* On some systems, Emacs defines static as nothing for the sake
  31    of unexec.  We don't want that here since we don't use unexec. */
  32 #undef static
  33 #endif
  34
  35 #undef TRUE
  36 #define TRUE    1
  37 #undef FALSE
  38 #define FALSE   0
  39
  40 /* Exit codes for success and failure.  */
  41 #ifdef VMS
  42 #define GOOD    1
  43 #define BAD     0
  44 #else
  45 #define GOOD    0
  46 #define BAD     1
  47 #endif
  48
  49 #define streq(s,t)      (strcmp (s, t) == 0)
  50 #define strneq(s,t,n)   (strncmp (s, t, n) == 0)
  51
  52 typedef int logical;
  53
  54 /*
  55  * A `struct linebuffer' is a structure which holds a line of text.
  56  * `readline' reads a line from a stream into a linebuffer and works
  57  * regardless of the length of the line.
  58  */
  59 struct linebuffer
  60 {
  61   long size;
  62   char *buffer;
  63 };
  64
  65 extern char *strtok();
  66
  67 long *xmalloc (), *xrealloc ();
  68 char *concat ();
  69 long readline ();
  70 void fatal ();
  71
  72 /*
  73  * xnew -- allocate storage.  SYNOPSIS: Type *xnew (int n, Type);
  74  */
  75 #define xnew(n, Type)   ((Type *) xmalloc ((n) * sizeof (Type)))
  76
  77
  78
  79 char *progname;
  80
  81 main (argc, argv)
  82      int argc;
  83      char **argv;
  84 {
  85   logical labels_saved, printing, header;
  86   time_t ltoday;
  87   char *labels, *p, *today;
  88   struct linebuffer data;
  89
  90 #ifdef MSDOS
  91   _fmode = O_BINARY;            /* all of files are treated as binary files */
  92   (stdout)->_flag &= ~_IOTEXT;
  93   (stdin)->_flag &= ~_IOTEXT;
  94 #endif
  95   if (argc != 1)
  96     {
  97       fprintf (stderr, "Usage: %s <babylmailbox >unixmailbox\n", progname);
  98       exit (GOOD);
  99     }
 100   labels_saved = printing = header = FALSE;
 101   progname = argv[0];
 102   ltoday = time (0);
 103   today = ctime (&ltoday);
 104   data.size = 200;
 105   data.buffer = xnew (200, char);
 106
 107   if (readline (&data, stdin) == 0
 108       || !strneq (data.buffer, "BABYL OPTIONS:", 14))
 109     fatal ("standard input is not a Babyl mailfile.");
 110
 111   while (readline (&data, stdin) > 0)
 112     {
 113       if (streq (data.buffer, "*** EOOH ***") && !printing)
 114         {
 115           printing = header = TRUE;
 116           printf ("From Babyl to mail by %s %s", progname, today);
 117           continue;
 118         }
 119
 120       if (data.buffer[0] == '\037')
 121         {
 122           if (data.buffer[1] == '\0')
 123             continue;
 124           else if (data.buffer[1] == '\f')
 125             {
 126               /* Save labels. */
 127               readline (&data, stdin);
 128               p = strtok (data.buffer, " ,\r\n\t");
 129               labels = "X-Babyl-Labels: ";
 130
 131               while (p = strtok (NULL, " ,\r\n\t"))
 132                 labels = concat (labels, p, ", ");
 133
 134               p = &labels[strlen (labels) - 2];
 135               if (*p == ',')
 136                 *p = '\0';
 137               printing = header = FALSE;
 138               labels_saved = TRUE;
 139               continue;
 140             }
 141         }
 142
 143       if ((data.buffer[0] == '\0') && header)
 144         {
 145           header = FALSE;
 146           if (labels_saved)
 147             puts (labels);
 148         }
 149
 150       if (printing)
 151         puts (data.buffer);
 152     }
 153 }
 154
 155
 156
 157 /*
 158  * Return a newly-allocated string whose contents
 159  * concatenate those of s1, s2, s3.
 160  */
 161 char *
 162 concat (s1, s2, s3)
 163      char *s1, *s2, *s3;
 164 {
 165   int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
 166   char *result = xnew (len1 + len2 + len3 + 1, char);
 167
 168   strcpy (result, s1);
 169   strcpy (result + len1, s2);
 170   strcpy (result + len1 + len2, s3);
 171   result[len1 + len2 + len3] = '\0';
 172
 173   return result;
 174 }
 175
 176 /*
 177  * Read a line of text from `stream' into `linebuffer'.
 178  * Return the number of characters read from `stream',
 179  * which is the length of the line including the newline, if any.
 180  */
 181 long
 182 readline (linebuffer, stream)
 183      struct linebuffer *linebuffer;
 184      register FILE *stream;
 185 {
 186   char *buffer = linebuffer->buffer;
 187   register char *p = linebuffer->buffer;
 188   register char *pend;
 189   int chars_deleted;
 190
 191   pend = p + linebuffer->size;  /* Separate to avoid 386/IX compiler bug.  */
 192
 193   while (1)
 194     {
 195       register int c = getc (stream);
 196       if (p == pend)
 197         {
 198           linebuffer->size *= 2;
 199           buffer = (char *) xrealloc (buffer, linebuffer->size);
 200           p += buffer - linebuffer->buffer;
 201           pend = buffer + linebuffer->size;
 202           linebuffer->buffer = buffer;
 203         }
 204       if (c == EOF)
 205         {
 206           chars_deleted = 0;
 207           break;
 208         }
 209       if (c == '\n')
 210         {
 211           if (p[-1] == '\r' && p > buffer)
 212             {
 213               *--p = '\0';
 214               chars_deleted = 2;
 215             }
 216           else
 217             {
 218               *p = '\0';
 219               chars_deleted = 1;
 220             }
 221           break;
 222         }
 223       *p++ = c;
 224     }
 225
 226   return (p - buffer + chars_deleted);
 227 }
 228
 229 /*
 230  * Like malloc but get fatal error if memory is exhausted.
 231  */
 232 long *
 233 xmalloc (size)
 234      unsigned int size;
 235 {
 236   long *result = (long *) malloc (size);
 237   if (result == NULL)
 238     fatal ("virtual memory exhausted");
 239   return result;
 240 }
 241
 242 long *
 243 xrealloc (ptr, size)
 244      char *ptr;
 245      unsigned int size;
 246 {
 247   long *result = (long *) realloc (ptr, size);
 248   if (result == NULL)
 249     fatal ("virtual memory exhausted");
 250   return result;
 251 }
 252
 253 void
 254 fatal (message)
 255 {
 256   fprintf (stderr, "%s: %s\n", progname, message);
 257   exit (BAD);
 258 }
 259