clib package

packages/clib/maildrop/rfc822/imapsubj.c

@@ -0,0 +1,254 @@
+/*
+** Copyright 2000 Double Precision, Inc.
+** See COPYING for distribution information.
+*/
+
+/*
+** $Id$
+*/
+#include	<stdio.h>
+#include	<ctype.h>
+#include	<stdlib.h>
+#include	<string.h>
+#include	"rfc822.h"
+#ifndef __WINDOWS__
+#include	"config.h"
+#endif
+
+#if	HAVE_STRCASECMP
+
+#else
+#define	strcasecmp	stricmp
+#endif
+
+#if	HAVE_STRNCASECMP
+
+#else
+#define	strncasecmp	strnicmp
+#endif
+
+
+/* Remove artifacts from the subject header */
+
+static void stripsubj(char *s, int *hasrefwd)
+{
+	char	*p;
+	char	*q;
+
+	for (p=q=s; *p; p++)
+	{
+		if (!isspace((int)(unsigned char)*p))
+		{
+			*q++=*p;
+			continue;
+		}
+		while (p[1] && isspace((int)(unsigned char)p[1]))
+		{
+			++p;
+		}
+		*q++=' ';
+	}
+	*q=0;
+
+	for (;;)
+	{
+		/*
+		**
+		** (2) Remove all trailing text of the subject that matches
+		** the subj-trailer ABNF, repeat until no more matches are
+		** possible.
+		**
+		**  subj-trailer    = "(fwd)" / WSP
+		*/
+
+		for (p=s; *p; p++)
+			;
+		while (p > s)
+		{
+			if ( isspace((int)(unsigned char)p[-1]))
+			{
+				--p;
+				continue;
+			}
+			if (p-s >= 5 && strncasecmp(p-5, "(FWD)", 5) == 0)
+			{
+				p -= 5;
+				*hasrefwd=1;
+				continue;
+			}
+			break;
+		}
+		*p=0;
+
+		for (p=s; *p; )
+		{
+			int isrefwd=0;
+
+			for (;;)
+			{
+				int needcolon=1;
+
+				/*
+				**
+				** (3) Remove all prefix text of the subject
+				** that matches the subj-leader ABNF.
+				**
+				**   subj-leader     = (*subj-blob subj-refwd) / WSP
+				**
+				**   subj-blob       = "[" *BLOBCHAR "]" *WSP
+				**
+				**   subj-refwd      = ("re" / ("fw" ["d"])) *WSP [subj-blob] ":"
+				**
+				**   BLOBCHAR        = %x01-5a / %x5c / %x5e-7f
+				**                   ; any CHAR except '[' and ']'
+				**
+				**   THIS IS A BUG: whitespace should also be excluded from BLOBCHAR
+				*/
+
+				if (isspace((int)(unsigned char)*p))
+				{
+					++p;
+					continue;
+				}
+				if (strncasecmp(p, "RE", 2) == 0)
+				{
+					q=p+2;
+					isrefwd=1;
+				}
+				else if (strncasecmp(p, "FWD", 3) == 0)
+				{
+					q=p+3;
+					isrefwd=1;
+				}
+				else if (strncasecmp(p, "FW", 2) == 0)
+				{
+					q=p+2;
+					isrefwd=1;
+				}
+				else if (*p == '[')
+				{
+					q=p;
+					needcolon=0;
+				}
+				else
+					break;
+
+				if (*q == '[')
+				{
+					++q;
+
+					while (*q && *q != '[' && *q != ']'
+					       && *q != ' ')
+						++q;
+
+					if (*q != ']')	break;
+					++q;
+				}
+				if (needcolon && *q++ != ':')	break;
+				p=q;
+			}
+			/*
+			** (4) If there is prefix text of the subject that
+			** matches the subj-blob ABNF, and removing that
+			** prefix leaves a non-empty subj-base, then remove
+			** the prefix text.
+			**
+			**   subj-base       = NONWSP *([*WSP] NONWSP)
+			**                   ; can be a subj-blob
+			*/
+
+
+			if (*p == '[')
+			{
+				for (q=p; *q; q++)
+					if (*q == '[' || *q == ' '
+					    || *q == ']')
+						break;
+				if (*q == ']')
+				{
+					++q;
+					while (*q && isspace((int)(unsigned
+								   char)*q))
+						++q;
+
+					if (*q)
+					{
+						p=q;
+						if (isrefwd)
+							*hasrefwd=1;
+						continue;
+					}
+				}
+			}
+			if (isrefwd)
+				*hasrefwd=1;
+
+			break;
+		}
+		/*
+		**
+		** (6) If the resulting text begins with the subj-fwd-hdr ABNF
+		** and ends with the subj-fwd-trl ABNF, remove the
+		** subj-fwd-hdr and subj-fwd-trl and repeat from step (2).
+		**
+		**   subj-fwd-hdr    = "[fwd:"
+		**
+		**   subj-fwd-trl    = "]"
+		*/
+
+		if (strncasecmp(p, "[FWD:", 5) == 0)
+		{
+			q=strrchr(p, ']');
+			if (q && q[1] == 0)
+			{
+				*q=0;
+				p += 5;
+
+				q=s;
+				while ( (*q++ = *p++) != 0)
+					;
+
+				*hasrefwd=1;
+				continue;
+			}
+		}
+		break;
+	}
+
+	q=s;
+	while ( (*q++ = *p++) != 0)
+		;
+}
+
+char *rfc822_coresubj(const char *s, int *hasrefwd)
+{
+	char *q=strdup(s), *r;
+	int dummy;
+
+	if (!hasrefwd)
+		hasrefwd= &dummy;
+
+	*hasrefwd=0;
+	if (!q)	return (0);
+
+	for (r=q; *r; r++)
+		if ((*r & 0x80) == 0)	/* Just US-ASCII casing, thanks */
+			*r=toupper((int)(unsigned char)*r);
+	stripsubj(q, hasrefwd);
+	return (q);
+}
+
+char *rfc822_coresubj_nouc(const char *s, int *hasrefwd)
+{
+	char *q=strdup(s);
+	int dummy;
+
+	if (!hasrefwd)
+		hasrefwd= &dummy;
+
+	*hasrefwd=0;
+	if (!q)	return (0);
+
+	stripsubj(q, hasrefwd);
+	return (q);
+}