#!/bin/bash
## date conversion from Apache-Logrecord-format -- by Eugene Reimer 2010-03;
## receives date+time+timezone in the form:  06/Mar/2010:01:58:16 -0500  and converts it to any FORMAT supported by date-command;
## USAGE
##	datecvt-from-Apache  [+FORMAT]  ApacheDate[ApacheTime] [ApacheTimezone]		--where FORMAT is as in date-cmd -- see man date
## EXAMPLES:
##	datecvt-from-Apache  +%Y-%m-%dT%H:%M%z  06/Mar/2010:01:58:16 -0500		--produces: 2010-03-06T00:58-0600  (in winter;  note timezone was supplied)
##	datecvt-from-Apache  +%Y-%m-%dT%H:%M%z  06/Mar/2010:01:58:16			--produces: 2010-03-06T01:58-0600  (in winter;  note timezone was omitted)

if [ $# -eq 0 ];then  echo "usage:  datecvt-from-Apache  [+FORMAT]  ApacheDate[ApacheTime] [ApacheTimezone]";  exit;  fi

FMT="+%Y-%m-%dT%H:%M%z"									##default for FORMAT
DT=;  for A in "$@";do if [[ $A == +* ]];then FMT="$A"; else DT="$DT$A";fi;done		##handle cmdline args, catenating onto $DT w/o space
DT=${DT//\/};  DT=${DT/:/ }								##remove all slashes, replace first colon with space
date -d"$DT" "$FMT"									##convert according to $FMT