Question: I want perform sha1sum `file1` and sha1sum `file2` and perform bitwise OR operation with them using bash. Output should be printable i.e 53a23bc2e24d039 ... (160 bit)

How can I do this?

I know

echo $(( 0xa | 0xb )) but how to extend to 40 hexadecimal digits?

Thanks

Answer: 
I don't think you really want a 160-bit inclusive OR, but if you do:

```
split32 () {
  x='s/\(........\)\(........\)\(........\)\(........\)\(........\)/'
  x=$x'0x\1 0x\2 0x\3 0x\4 0x\5/'
  sed -e "$x"
}

(sha1sum $1 | split32; sha1sum $2 | split32) | (
    read a1 b1 c1 d1 e1 x1
    read a2 b2 c2 d2 e2 x2
    a=$(($a1 | $a2))
    b=$(($b1 | $b2))
    c=$(($c1 | $c2))
    d=$(($d1 | $d2))
    e=$(($e1 | $e2))
    printf '  %08x%08x%08x%08x%08x\n' $a1 $b1 $c1 $d1 $e1
    printf '+ %08x%08x%08x%08x%08x\n' $a2 $b2 $c2 $d2 $e2
    printf '= %08x%08x%08x%08x%08x\n' $a  $b  $c  $d  $e 
)
$ bash bigOr.sh fun.tar fun.tgz
  e515d3813b17c36b9a7d29f7aea3e79e264449b7
+ 4f201513105c301944d0a0ba5864d9f07544ca76
= ef35d7933b5ff37bdefda9fffee7fffe7744cbf7

```
Try this:

```
val1=$(sha1sum file1)
val1=${val1% *}
val2=$(sha1sum file2)
val2=${val2% *}
val3=$(( 0x$val1 | 0x$val2 ))
printf "%x\n" $val3

```