Shell Programming and Scripting

Hi,
We are using AIX and while using KSH Unix script, we are reading data in a file and then using the if statement for comparison. The code with if statement is as follows;

Code:

 
cat $FILETMP | while read a
do
        jobstr1=`echo $a | awk '{print $1}'`
        var1=`echo $jobstr1 | cut -c 9`
        var2=`echo $jobstr1 | cut -c 17`
        if [ $var1 = _ -a $var2 = _ ]
        then
                echo "$a" >> $outfile
        fi
done

The code is working fine and writing the data to the file "outfile", but the code gives errors. The errors are when the characters are "empty" or "blank" then while comparing the system is giving errors as follows;

ksh: _: unknown test operator
ksh: test: argument expected

Please help to have the code without having error messages. I would also like to know if there is a better way of doing this.
Thanks for the help.

Try:

Code:

if [ "${var1}." = "_." -a "${var2}." = "_." ]

Here is two alternative ways to do it:

Code:

while read line
do
  case $line in 
    ????????_???????_*) echo "$line"
  esac
done < "$FILETMP" > "$outfile"

Code:

awk -F "" '$9=="_"&&$17=="_"' "$FILETMP" > "$outfile"

Thanks to all,

All the options works fine.