+
+
+/*
+ * Look for a particular header field in an RFC822 message text. If the
+ * requested field is found, it is unfolded (if necessary) and returned to
+ * the caller. The field name is stripped out, leaving only its contents.
+ * The caller is responsible for freeing the returned buffer. If the requested
+ * field is not present, or anything else goes wrong, it returns NULL.
+ */
+char *rfc822_fetch_field(char *rfc822, char *fieldname) {
+ int pos = 0;
+ int beg, end;
+ int done = 0;
+ int colonpos, i;
+ char *fieldbuf = NULL;
+
+ /* Should never happen, but sometimes we get stupid */
+ if (rfc822 == NULL) return(NULL);
+ if (fieldname == NULL) return(NULL);
+
+ while (!done) {
+
+ /* Locate beginning and end of field, keeping in mind that
+ * some fields might be multiline
+ */
+ beg = pos;
+ end = (-1);
+ for (pos=beg; ((pos<=strlen(rfc822))&&(end<0)); ++pos) {
+ if ((rfc822[pos]=='\n')
+ && (!isspace(rfc822[pos+1]))) {
+ end = pos;
+ }
+ if ( (rfc822[pos]=='\n') /* done w. headers? */
+ && ( (rfc822[pos+1]=='\n')
+ ||(rfc822[pos+1]=='\r'))) {
+ end = pos;
+ done = 1;
+ }
+
+ }
+
+ /* At this point we have a field. Is it The One? */
+ if (end > beg) {
+ fieldbuf = mallok((end-beg)+3);
+ if (fieldbuf == NULL) return(NULL);
+ safestrncpy(fieldbuf, &rfc822[beg], (end-beg)+1);
+ unfold_rfc822_field(fieldbuf);
+ colonpos = (-1);
+ for (i = strlen(fieldbuf); i >= 0; --i) {
+ if (fieldbuf[i] == ':') colonpos = i;
+ }
+ if (colonpos > 0) {
+ fieldbuf[colonpos] = 0;
+ if (!strcasecmp(fieldbuf, fieldname)) {
+ strcpy(fieldbuf, &fieldbuf[colonpos+1]);
+ striplt(fieldbuf);
+ return(fieldbuf);
+ }
+ }
+ phree(fieldbuf);
+ }
+
+ /* If we've hit the end of the message, bail out */
+ if (pos > strlen(rfc822)) done = 1;
+ }
+ return(NULL);
+}