- Parameters:
- 
  
    |  | tag | tag to choose which matches to count, or -1 for all |  
 
- Returns:
- count of matched messages
Calculate and return the number of messages emitted to 
syslog which matched a regexp set up earlier using 
np_syslog_match. If 
tag is less than zero, all match counts will be returned, otherwise only the match counts for regexps registered with the same tag will be returned.