#!/bin/bash
# weberrors - Scans through an Apache error_log file and reports the 
#    most important errors, then lists additional entries.

setglobal temp = ""/tmp/$[basename $0].$Pid""

# The following three lines will need to be customized for your own
# installation for this script to work best.

setglobal htdocs = '"/usr/local/etc/httpd/htdocs/'"
setglobal myhome = '"/usr/home/taylor/'"
setglobal cgibin = '"/usr/local/etc/httpd/cgi-bin/'"

setglobal sedstr = ""s/^/  /g;s|$htdocs|[htdocs]  |;s|$myhome|[homedir] |;s|$cgibin|[cgi-bin] |""

setglobal screen = '"(File does not exist|Invalid error redirect|premature EOF|Premature end of script|script not found)'" 

setglobal length = '5'                # entries per category to display

proc checkfor 
{
  grep "$(2):" $1 | awk '{print $NF}' |\
    sort | uniq -c | sort -rn | head -$length | sed $sedstr > $temp

  if test $[wc -l < $temp] -gt 0  {
    echo ""
    echo "$2 errors:"
    cat $temp
  }
}

trap "$[which rm] -f $temp" 0

if test $1 = "-l"  {
  setglobal length = $2; shift 2
}

if test $Argc -ne 1 -o ! -r $1  {
  echo "Usage: $[basename $0] [-l len] error_log" > !2
  exit 1
}

echo Input file $1 has $[wc -l < $1] entries.

setglobal start = $[grep -E '\[.*:.*:.*\]' $1 | head -1 | awk '{print $1" "$2" "$3" "$4" "$5 }]
setglobal end = $[grep -E '\[.*:.*:.*\]' $1 | tail -1 | awk '{print $1" "$2" "$3" "$4" "$5 }]
/bin/echo -n "Entries from $start to $end"

echo ""

### Check for various common and well-known errors:

checkfor $1 "File does not exist"
checkfor $1 "Invalid error redirection directive"
checkfor $1 "premature EOF"
checkfor $1 "script not found or unable to stat" 
checkfor $1 "Premature end of script headers" 

grep -vE $screen $1 | grep "\[error\]" | grep "\[client " | \
  sed 's/\[error\]/\`/' | cut -d'`'  -f2 | cut -d' ' -f4- | \
sort | uniq -c | sort -rn | sed 's/^/  /' | head -$length > $temp

if test $[wc -l < $temp] -gt 0  {
  echo ""
  echo "Additional error messages in log file:"
  cat $temp
}

echo ""
echo "And non-error messages occurring in the log file:"

grep -vE $screen $1 | grep -v "\[error\]" | \
  sort | uniq -c | sort -rn | \
  sed 's/^/  /' | head -$length

exit 0