Hi,

I have a value stored in x and I need to compare it to the numbers in every other line of a file. The file contains alternating lines of numbers and letters:

aaaa1111
AAAAAAAA
bbbb2222
BBBBBBBB
cccc3333
CCCCCCCC

I need to compare x to the numbers in every other line without the first four characters of that line. So I want to compare x to 1111, then to 2222, then 3333. This is to be the condition in an if statement:

if [ $x = (line 1 without first four characters) ]
or
if [ $x = (line 3 without first four characters) ]

I know I would have to use something along the lines of = $(sed something) or maybe cut, but I don't know how to reference the file by line.

Let me know if I need to be more clear. Thanks for any help!

If you have access to Perl, you could try something like this:

perl -lane '$x = 2222;print "Match Found: $_ -> $1" if /.*?($x)/' file

Match Found: bbbb2222 -> 2222

Here is a bash (or ksh) script that will do what you want entirely in shell and using awk:

x=${1:-2222}
odd=1
while read data
do      if [ $odd = 1 ] && [ "x$x" = "x${data#????}" ]
        then    echo match found in "$data"
        fi
        odd=$((1 - odd))
done < input

awk -v x="$x" 'NR%2{if(x==substr($0,5)) printf("match found in %s\n",$0)}' input