UNIX for Advanced & Expert Users

#!/bin/ksh

         
CUR_SHELL="/bin/ksh"
FIELD1="VAR1"
FIELD2="VAR2"
NUM_INST=0
GREP_PATTERN=$0
typeset -u OVERRIDE_PARM  
OVERRIDE_PARM=$1         # a parameter to force the execution of the script - if its OVERRIDE, than the script must run anyway.


echo "$GREP_PATTERN" | grep './' 
if [ $? -eq 0 ]; then
    GREP_PATTERN=`echo $GREP_PATTERN | sed -e 's/.\///'`
    
fi

#echo "$1" | tr "[:lower:]" "[:upper:]"     both methods work, but
#echo "$1" | sed -e 's/surpass/SURPASS/'   using typeset doesn't require an extra process for this conversion

if [ "$OVERRIDE_PARM" != "OVERRIDE" ]; then
    ps -e -o args | grep "$GREP_PATTERN" | tr -s " " | cut -d" " -f1,2 |
    while read -r FIELD1 FIELD2
    do
        if [ "$FIELD1" = "$CUR_SHELL" ]; then
            echo $FIELD2 | grep "$GREP_PATTERN"
            if [ $? -eq 0 ]; then
                NUM_INST=$NUM_INST+1 
                if [ $NUM_INST -gt 1 ]; then    
                    echo "Error - Program is already running."
                    exit 1
                fi
            fi
        fi 
    done
fi

function ()
{
    echo "PARAMETER: $1"
    sleep 60            
}

function 1&
function 2&

wait