token_assignment

#!/bin/bash
#Function to replace an assignement value with a token string
function token_assignement(){
    #VNAME is variable name to replace
    #FNAME is file name to make substitution in
    #TOKEN is number of token to use (not string)
    #INSTANCE is number of the instance to replace, defaults to 1. If this is less then one then loop
    #over all matches

    #Set locals based on input
    local  VNAME=${1}
    local  FNAME=${2}
    local  TOKEN=${3}
    local  INSTANCE=${4:-1}

    #Set local constants
    local TOK_STRING="VAR_REPLACE_"
    
    #Get the number of matches
    local NMATCH=`grep -n -E "^ *""${VNAME}"" *= *" ${FNAME} | wc -l`

    #Now get the line number of instance matching VNAME assignment
    local LN_NUM=`grep -n -E "^ *""${VNAME}"" *= *" ${FNAME} | head -n ${INSTANCE} | tail -n 1 | awk -F ':' '{print $1}'`
    
    #If more than one match see if we pick specific value or do all
    local COUNT=0
    if [ ${NMATCH} -gt 1 ]
    then
	if [ ${INSTANCE} -lt 0 ]
	then
	    for i in `grep -n -E "^ *""${VNAME}"" *= *" ${FNAME} | awk -F ':' '{print $1}'`
	    do
		local LIN[${COUNT}]=${i}
		COUNT=`calc ${COUNT}+1`
	    done
	else
	    local LIN[${COUNT}]=${LN_NUM}
	fi
    else
	local LIN[${COUNT}]=${LN_NUM}
    fi

    #Now replace string to left of value with assigment and token in desired lines
    for LINNUM in ${LIN[@]}
    do
	sed --in-place  ''"${LINNUM}"' s/^\( *'"${VNAME}"' *\= *\)\(.*\)$/\1'"${TOK_STRING}""${TOKEN}"' ! \2/g' ${FNAME}
    done
}