mdw@git.distorted.org.uk Git - ezmlm/blob - decodeHDR.c

   1 /*$Id: decodeHDR.c,v 1.2 1998/02/28 19:03:02 lindberg Exp $*/
   2 /*$Name: ezmlm-idx-040 $*/
   3
   4 #include "stralloc.h"
   5 #include "strerr.h"
   6 #include "error.h"
   7 #include "case.h"
   8 #include "byte.h"
   9 #include "uint32.h"
  10 #include "mime.h"
  11 #include "errtxt.h"
  12
  13 static void die_nomem(fatal)
  14   char *fatal;
  15 {
  16   strerr_die2x(111,fatal,ERR_NOMEM);
  17 }
  18
  19 void decodeHDR(indata,n,outdata,charset,fatal)
  20 char *indata;
  21 unsigned int n;
  22 stralloc *outdata;
  23 char *charset;
  24 char *fatal;
  25
  26 /* decodes indata depending on charset. May put '\n' and '\0' into out */
  27 /* data and can take them as indata. */
  28 {
  29   unsigned int pos;
  30   char *cp,*cpnext,*cpstart,*cpenc,*cptxt,*cpend,*cpafter;
  31
  32   cpnext = indata;
  33   cpafter = cpnext + n;
  34   cpstart = cpnext;
  35   if (!stralloc_copys(outdata,"")) die_nomem(fatal);
  36   if (!stralloc_ready(outdata,n)) die_nomem(fatal);
  37   for (;;) {
  38     cpstart = cpstart + byte_chr(cpstart,cpafter-cpstart,'=');
  39     if (cpstart == cpafter)
  40       break;
  41     ++cpstart;
  42     if (*cpstart != '?')
  43       continue;
  44     ++cpstart;
  45     cpenc = cpstart + byte_chr(cpstart,cpafter-cpstart,'?');
  46     if (cpenc == cpafter)
  47       continue;
  48     cpenc++;
  49     cptxt = cpenc + byte_chr(cpenc,cpafter-cpenc,'?');
  50     if (cptxt == cpafter)
  51       continue;
  52     cptxt++;
  53     cpend = cptxt + byte_chr(cptxt,cpafter-cptxt,'?');
  54     if (cpend == cpafter || *(cpend + 1) != '=')
  55       continue;
  56         /* We'll decode anything. On lists with many charsets, this may */
  57         /* result in unreadable subjects, but that's the case even if   */
  58         /* no decoding is done. This way, the subject will be optimal   */
  59         /* for threading, but charset info is lost. We aim to correctly */
  60         /* decode us-ascii and all iso-8859/2022 charsets. Exacly how   */
  61         /* these will be displayed depends on dir/charset.              */
  62     cp = cpnext;
  63                         /* scrap lwsp between coded strings */
  64     while (*cp == ' ' || *cp == '\t')
  65       cp++;
  66     if (cp != cpstart - 2)
  67       if (!stralloc_catb(outdata,cpnext, cpstart - cpnext - 2))
  68                 die_nomem(fatal);
  69    cpnext = cp + 1;
  70    cpstart = cpnext;
  71           switch (*cpenc) {
  72             case 'b':
  73             case 'B':
  74               pos = outdata->len;
  75               decodeB(cptxt,cpend-cptxt,outdata,2,fatal);
  76               cpnext = cpend + 2;
  77               cpstart = cpnext;
  78               break;
  79             case 'q':
  80             case 'Q':
  81               decodeQ(cptxt,cpend-cptxt,outdata,fatal);
  82               cpnext = cpend + 2;
  83               cpstart = cpnext;
  84               break;
  85             default:            /* shouldn't happen, but let's be reasonable */
  86               cpstart = cpend + 2;
  87               break;
  88           }
  89   }
  90   if (!stralloc_catb(outdata,cpnext,indata-cpnext+n)) die_nomem(fatal);
  91 }
  92