enhance: regex nomatch option "ZERO" has been added

This allows to return the string 0 if a regular expression is
not found. This is probably useful for storing numerical values into
database columns.

5 files changed, 17 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index e6a2b899..84617825 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 ---------------------------------------------------------------------------
 Version 3.20.1 [v3-stable] (rgerhards), 2008-11-??
+- enhance: regex nomatch option "ZERO" has been added
+  This allows to return the string 0 if a regular expression is
+  not found. This is probably useful for storing numerical values into
+  database columns.
 - doc update: documented how to specify multiple property replacer
   options + link to new online regex generator tool added
 - improved debug output for regular expressions inside property replacer
diff --git a/doc/property_replacer.html b/doc/property_replacer.html
index 0b4f1a01..2748dc89 100644
--- a/doc/property_replacer.html
+++ b/doc/property_replacer.html
@@ -219,10 +219,11 @@ that the first match is number 0, the second 1 and so on. Up to 10 matches
 (up to number 9) are supported. Please note that it would be more
 natural to have the match-number in front of submatch, but this would break 
 backward-compatibility. So the match-number must be specified after "nomatch".
-<p>nomatch is either "DFLT", "BLANK" or "FIELD" (all upper case!). It tells
+<p>nomatch is either "DFLT", "BLANK", ZERO or "FIELD" (all upper case!). It tells
 what to use if no match is found. With "DFLT", the strig "**NO MATCH**" is
 used. This was the only supported value up to rsyslog 3.19.5. With "BLANK"
-a blank text is used (""). Finally, "FIELD" uses the full property text
+a blank text is used (""). With "ZERO", "0" is used.
+Finally, "FIELD" uses the full property text
 instead of the expression. Some folks have requested that, so it seems
 to be useful.
 <p>The following is a sample of an ERE expression that takes the first
diff --git a/runtime/msg.c b/runtime/msg.c
index fcd4a6d3..c8dbf2c2 100644
--- a/runtime/msg.c
+++ b/runtime/msg.c
@@ -1936,6 +1936,8 @@ char *MsgGetProp(msg_t *pMsg, struct templateEntry *pTpe,
 						}
 						if(pTpe->data.field.nomatchAction == TPL_REGEX_NOMATCH_USE_DFLTSTR)
 							return "**NO MATCH**";
+						else if(pTpe->data.field.nomatchAction == TPL_REGEX_NOMATCH_USE_ZERO)
+							return "0";
 						else
 							return "";
 					}
diff --git a/template.c b/template.c
index 2fe23710..936ccd07 100644
--- a/template.c
+++ b/template.c
@@ -558,13 +558,17 @@ static int do_Parameter(unsigned char **pp, struct template *pTpl)
 					pTpe->data.field.nomatchAction = TPL_REGEX_NOMATCH_USE_DFLTSTR;
 					p += 4; /* eat indicator sequence */
 				} else if(p[0] == 'B' && p[1] == 'L' && p[2] == 'A' && p[3] == 'N' && p[4] == 'K'
-				   && (p[5] == ',' || p[5] == ':')) {
+				          && (p[5] == ',' || p[5] == ':')) {
 					pTpe->data.field.nomatchAction = TPL_REGEX_NOMATCH_USE_BLANK;
 					p += 5; /* eat indicator sequence */
 				} else if(p[0] == 'F' && p[1] == 'I' && p[2] == 'E' && p[3] == 'L' && p[4] == 'D'
-				   && (p[5] == ',' || p[5] == ':')) {
+				          && (p[5] == ',' || p[5] == ':')) {
 					pTpe->data.field.nomatchAction = TPL_REGEX_NOMATCH_USE_WHOLE_FIELD;
 					p += 5; /* eat indicator sequence */
+				} else if(p[0] == 'Z' && p[1] == 'E' && p[2] == 'R' && p[3] == 'O'
+				          && (p[4] == ',' || p[4] == ':')) {
+					pTpe->data.field.nomatchAction = TPL_REGEX_NOMATCH_USE_ZERO;
+					p += 4; /* eat indicator sequence */
 				} else if(p[0] == ',') { /* empty, use default */
 					pTpe->data.field.nomatchAction = TPL_REGEX_NOMATCH_USE_DFLTSTR;
 					 /* do NOT eat indicator sequence, as this was already eaten - the 
diff --git a/template.h b/template.h
index 6e889c58..318f3f32 100644
--- a/template.h
+++ b/template.h
@@ -78,7 +78,8 @@ struct templateEntry {
 			enum {
 				TPL_REGEX_NOMATCH_USE_DFLTSTR = 0, /* use the (old style) default "**NO MATCH**" string */
 				TPL_REGEX_NOMATCH_USE_BLANK = 1, /* use a blank string */
-				TPL_REGEX_NOMATCH_USE_WHOLE_FIELD = 2 /* use the full field contents that we were searching in*/
+				TPL_REGEX_NOMATCH_USE_WHOLE_FIELD = 2, /* use the full field contents that we were searching in*/
+				TPL_REGEX_NOMATCH_USE_ZERO = 3 /* use  0 (useful for numerical values) */
 			}  nomatchAction;	/**< what to do if we do not have a match? */
 			
 #endif