#! /usr/bin/env bash

# $Header: /home/ubuntu/mnt/e9_copy/MITgcm_contrib/jmc_script/extract_MON,v 1.1 2020/11/09 17:36:04 jmc Exp $
# $Name:  $

tmpfil=TTT.$$
if [ $# -le 1 ]
then
  echo 'Usage: '`basename $0`' file_input file_output [n]'
  echo '  ==> extract lines with "MON" out off file_input to file_output'
  echo '      start at the 1rst [or n^th] "%MON time_tsnumber"'
  echo '   or (n<0) after the (-n)^th line that match the last record'
  exit
else
 if test $# = 2 ; then n1=1 ; else n1=$3 ; fi
 file=$1 ; output=$2 ;
 echo '  ==> extract lines with "MON" out off file='$file ' to '$output
fi
#----------------------------------------------------------
touch $output $tmpfil
sed -n '/%MON/p' $1 | sed 's/(PID\.TID 000.\.000.) //g' >> $tmpfil
#egrep '%MON|cg2d_init_res' $1 | sed 's/(PID\.TID 000.\.000.) //g' >> $tmpfil

if test $n1 = 0
then
 echo '      take all lines'
 cat $tmpfil >> $output
 rm -f $tmpfil
 exit
fi

if [ $n1 -lt 0 ]
then
#- used to add the 1rst "Shap global diagnostic" (if test $n1 = -1):
#  select lines starting just after the -$n1 ^th line that match the last record
 n0=`expr 0 - $n1`
 line=`tail -1 $tmpfil | sed 's/= .....................//g'`
 num0=`sed -n "/$line/=" $tmpfil | sed -n "$n0 p"`
 num1=`expr $num0 + 1`
else
#  select lines starting at the $n1 ^th "time_tsnumber" record
 num1=`sed -n '/%MON time_tsnumber/=' $tmpfil | sed -n "$n1 p"`
fi
echo '      start at line' $num1 ' :'
sed -n "$num1 p" $tmpfil

sed -n "$num1,$ p" $tmpfil >> $output
rm -f $tmpfil
exit