rfc822/imapsubj.c

   1 /*
   2 ** Copyright 2000 Double Precision, Inc.
   3 ** See COPYING for distribution information.
   4 */
   5
   6 /*
   7 ** $Id: imapsubj.c,v 1.10 2006/04/11 02:24:59 mrsam Exp $
   8 */
   9 #include        <stdio.h>
  10 #include        <ctype.h>
  11 #include        <stdlib.h>
  12 #include        <string.h>
  13 #include        "rfc822.h"
  14 #include        "config.h"
  15
  16 #if     HAVE_STRCASECMP
  17
  18 #else
  19 #define strcasecmp      stricmp
  20 #endif
  21
  22 #if     HAVE_STRNCASECMP
  23
  24 #else
  25 #define strncasecmp     strnicmp
  26 #endif
  27
  28 /* Skip over blobs */
  29
  30 static char *skipblob(char *p, char **save_blob_ptr)
  31 {
  32         char *q;
  33         char *orig_p=p;
  34         int isalldigits=1;
  35
  36         if (*p == '[')
  37         {
  38                 for (q= p+1; *q; q++)
  39                         if (*q == '[' || *q == ']')
  40                                 break;
  41                         else if (strchr("0123456789", *q) == NULL)
  42                                 isalldigits=0;
  43
  44                 if (*q == ']')
  45                 {
  46                         p=q+1;
  47
  48                         while (isspace((int)(unsigned char)*p))
  49                         {
  50                                 ++p;
  51                         }
  52
  53                         if (save_blob_ptr && *save_blob_ptr && !isalldigits)
  54                         {
  55                                 while (orig_p != p)
  56                                         *(*save_blob_ptr)++=*orig_p++;
  57                         }
  58
  59                         return (p);
  60                 }
  61         }
  62         return (p);
  63 }
  64
  65 static char *skipblobs(char *p, char **save_blob_ptr)
  66 {
  67         char *q=p;
  68
  69         do
  70         {
  71                 p=q;
  72                 q=skipblob(p, save_blob_ptr);
  73         } while (q != p);
  74         return (q);
  75 }
  76
  77 /* Remove artifacts from the subject header */
  78
  79 static void stripsubj(char *s, int *hasrefwd, char *save_blob_buf)
  80 {
  81         char    *p;
  82         char    *q;
  83         int doit;
  84
  85         for (p=q=s; *p; p++)
  86         {
  87                 if (!isspace((int)(unsigned char)*p))
  88                 {
  89                         *q++=*p;
  90                         continue;
  91                 }
  92                 while (p[1] && isspace((int)(unsigned char)p[1]))
  93                 {
  94                         ++p;
  95                 }
  96                 *q++=' ';
  97         }
  98         *q=0;
  99
 100         do
 101         {
 102                 doit=0;
 103                 /*
 104                 **
 105                 ** (2) Remove all trailing text of the subject that matches
 106                 ** the subj-trailer ABNF, repeat until no more matches are
 107                 ** possible.
 108                 **
 109                 **  subj-trailer    = "(fwd)" / WSP
 110                 */
 111
 112                 for (p=s; *p; p++)
 113                         ;
 114                 while (p > s)
 115                 {
 116                         if ( isspace((int)(unsigned char)p[-1]))
 117                         {
 118                                 --p;
 119                                 continue;
 120                         }
 121                         if (p-s >= 5 && strncasecmp(p-5, "(FWD)", 5) == 0)
 122                         {
 123                                 p -= 5;
 124                                 *hasrefwd |= CORESUBJ_FWD;
 125                                 continue;
 126                         }
 127                         break;
 128                 }
 129                 *p=0;
 130
 131                 for (p=s; *p; )
 132                 {
 133                         for (;;)
 134                         {
 135                                 char *orig_blob_ptr;
 136                                 int flag=CORESUBJ_FWD;
 137
 138                                 /*
 139                                 **
 140                                 ** (3) Remove all prefix text of the subject
 141                                 ** that matches the subj-leader ABNF.
 142                                 **
 143                                 **   subj-leader     = (*subj-blob subj-refwd) / WSP
 144                                 **
 145                                 **   subj-blob       = "[" *BLOBCHAR "]" *WSP
 146                                 **
 147                                 **   subj-refwd      = ("re" / ("fw" ["d"])) *WSP [subj-blob] ":"
 148                                 **
 149                                 **   BLOBCHAR        = %x01-5a / %x5c / %x5e-7f
 150                                 **                   ; any CHAR except '[' and ']'
 151                                 */
 152
 153                                 if (isspace((int)(unsigned char)*p))
 154                                 {
 155                                         ++p;
 156                                         continue;
 157                                 }
 158
 159                                 q=skipblobs(p, NULL);
 160
 161                                 if (strncasecmp(q, "RE", 2) == 0)
 162                                 {
 163                                         flag=CORESUBJ_RE;
 164                                         q += 2;
 165                                 }
 166                                 else if (strncasecmp(q, "FWD", 3) == 0)
 167                                 {
 168                                         q += 3;
 169                                 }
 170                                 else if (strncasecmp(q, "FW", 2) == 0)
 171                                 {
 172                                         q += 2;
 173                                 }
 174                                 else q=0;
 175
 176                                 if (q)
 177                                 {
 178                                         orig_blob_ptr=save_blob_buf;
 179
 180                                         q=skipblob(q, &save_blob_buf);
 181                                         if (*q == ':')
 182                                         {
 183                                                 p=q+1;
 184                                                 *hasrefwd |= flag;
 185                                                 continue;
 186                                         }
 187
 188                                         save_blob_buf=orig_blob_ptr;
 189                                 }
 190
 191
 192                                 /*
 193                                 ** (4) If there is prefix text of the subject
 194                                 ** that matches the subj-blob ABNF, and
 195                                 ** removing that prefix leaves a non-empty
 196                                 ** subj-base, then remove the prefix text.
 197                                 **
 198                                 **   subj-base       = NONWSP *([*WSP] NONWSP)
 199                                 **                   ; can be a subj-blob
 200                                 */
 201
 202                                 orig_blob_ptr=save_blob_buf;
 203
 204                                 q=skipblob(p, &save_blob_buf);
 205
 206                                 if (q != p && *q)
 207                                 {
 208                                         p=q;
 209                                         continue;
 210                                 }
 211                                 save_blob_buf=orig_blob_ptr;
 212                                 break;
 213                         }
 214
 215                         /*
 216                         **
 217                         ** (6) If the resulting text begins with the
 218                         ** subj-fwd-hdr ABNF and ends with the subj-fwd-trl
 219                         ** ABNF, remove the subj-fwd-hdr and subj-fwd-trl and
 220                         ** repeat from step (2).
 221                         **
 222                         **   subj-fwd-hdr    = "[fwd:"
 223                         **
 224                         **   subj-fwd-trl    = "]"
 225                         */
 226
 227                         if (strncasecmp(p, "[FWD:", 5) == 0)
 228                         {
 229                                 q=strrchr(p, ']');
 230                                 if (q && q[1] == 0)
 231                                 {
 232                                         *q=0;
 233                                         p += 5;
 234                                         *hasrefwd |= CORESUBJ_FWD;
 235
 236                                         for (q=s; (*q++=*p++) != 0; )
 237                                                 ;
 238                                         doit=1;
 239                                 }
 240                         }
 241                         break;
 242                 }
 243         } while (doit);
 244
 245         q=s;
 246         while ( (*q++ = *p++) != 0)
 247                 ;
 248         if (save_blob_buf)
 249                 *save_blob_buf=0;
 250 }
 251
 252 char *rfc822_coresubj(const char *s, int *hasrefwd)
 253 {
 254         char *q=strdup(s), *r;
 255         int dummy;
 256
 257         if (!hasrefwd)
 258                 hasrefwd= &dummy;
 259
 260         *hasrefwd=0;
 261         if (!q) return (0);
 262
 263         for (r=q; *r; r++)
 264                 if ((*r & 0x80) == 0)   /* Just US-ASCII casing, thanks */
 265                         *r=toupper((int)(unsigned char)*r);
 266         stripsubj(q, hasrefwd, 0);
 267         return (q);
 268 }
 269
 270 char *rfc822_coresubj_nouc(const char *s, int *hasrefwd)
 271 {
 272         char *q=strdup(s);
 273         int dummy;
 274
 275         if (!hasrefwd)
 276                 hasrefwd= &dummy;
 277
 278         *hasrefwd=0;
 279         if (!q) return (0);
 280
 281         stripsubj(q, hasrefwd, 0);
 282         return (q);
 283 }
 284
 285 char *rfc822_coresubj_keepblobs(const char *s)
 286 {
 287         char *q=strdup(s), *r;
 288         int dummy;
 289
 290         if (!q) return (0);
 291
 292         r=strdup(s);
 293         if (!r)
 294         {
 295                 free(q);
 296                 return (0);
 297         }
 298
 299         stripsubj(q, &dummy, r);
 300         strcat(r, q);
 301         free(q);
 302         return (r);
 303 }