#!/bin/sh
# This program is part of Aspersa (http://code.google.com/p/aspersa/)

# Author: Baron Schwartz

usage() {
   echo "Usage: $0 [-r] -- commandline"
   echo "   -r     Relative: subtract each column from the previous column."
   echo "   --     Option separator; after this, all arguments are passed"
   echo "          to the program whose output mext will columnize."
   echo "mext columnizes repeated output from a program like mysqladmin extended:"
   echo "   mext -r -- mysqladmin ext -i10 -c3"
   echo "You can also work with data from a file:"
   echo "   mext -r -- cat mysqladmin-output.txt"
   exit 1
}

if [ -z "$1" ]; then
   usage;
fi

FILE=/tmp/mext_temp_file;
NUM=0;
REL=0;
rm -f $FILE*;

# Command-line parsing.
args=`getopt -u -n mext r "$@"`;
if [ "$?" = "1" ]; then
   usage;
fi
set -- $args
for o; do
   case "$o" in
      -r)   REL="1"; shift;;
      --)   shift;   break;;
   esac
done

if [ -z "$1" ]; then
   usage;
fi

# Split the output on empty lines and put each into a different file; eliminate
# lines that don't have "real" content.
$@ | grep -v '+' | grep -v Variable_name | sed 's/|//g' \
   | while read line; do
   if [ "$line" = "" ]; then
      NUM=`expr $NUM + 1`;
      echo "" > $FILE$NUM;
   fi
   echo "$line" >> $FILE$NUM;
done

# Count how many files there are and prepare to format the output
SPEC="%-33s %13d"
AWKS=""
NUM=`ls $FILE* | wc -l`;
# The last file will be empty...
NUM=`expr $NUM - 3`;

# Join each file with the next file, joining on the first field. Build a printf
# spec and awk spec at the same time.
for i in `seq 0 $NUM`; do
   NEXTFILE=`expr $i + 1`;

   # Sort each file and eliminate empty lines, so 'join' doesn't complain.
   sort $FILE$i | grep . > $FILE$i.tmp;
   mv $FILE$i.tmp $FILE$i;
   sort $FILE${NEXTFILE} | grep . > $FILE${NEXTFILE}.tmp;
   mv $FILE${NEXTFILE}.tmp $FILE${NEXTFILE};

   # Join the files together.  This gets slow O(n^2) as we add more files, but
   # this really shouldn't be performance critical.
   join $FILE$i $FILE${NEXTFILE} | grep . > $FILE;

   # Find the max length of the [numeric only] values in the file so we know how
   # wide to make the columns
   MAXLEN=`awk '{print $2}' $FILE${NEXTFILE} | grep -v '[^0-9]' | awk '{print length($1)}' | sort -rn | head -n1`
   mv $FILE $FILE${NEXTFILE};
   SPEC="$SPEC %${MAXLEN}d";
   if [ "$REL" = "1" ]; then
      AWKS="$AWKS, \$`expr $i + 3` - \$`expr $i + 2`";
   else
      AWKS="$AWKS, \$`expr $i + 3`";
   fi
done

# Print output
AWKCMD="printf(\"$SPEC\n\", \$1, \$2$AWKS);";
awk "{$AWKCMD}" $FILE`expr $NUM + 1`;

# Remove all temporary files.
rm -f $FILE*;