Question

I know that is a duplicate question from here : Link

I tried to do a little more research into if its possible or no at-all.
and I see that it is possible.

The only thing I want to get is what is the function that I need to use to convert a string to an integer in shell scripting. SHA1 is a 160bit long integer.

Motivation behind doing it on shell scripting : trying to learning it.

For example I get the sha1 of a file by storing it in a variable like this

store=`sha1 $blah | cut -d  ' ' -f 1`

it gives me the hash . But what if I want to convert it to integer.

Answer 1

Impossible. For the shell, everything is a string. If you leave POSIX, and declare shell variables as having integer type, the width of the integer is usually that of the underlying C library, i.e. 32 or 64 bit. SHA1 hashes with 160bits don’t fit.
However, there are the bc and dc utilities, which allow arbitrary precision arithmetic.
If you just want to convert the hex string to a decimal number, use this:

$ bc << EOF
obase=10
ibase=16
DA19BAC0F234635B6DE9362369DA07A6A4162865
1245133775210903227706347819370390008085985241189
EOF

Note that you MUST USE CAPITAL HEX DIGITS, because bc won’t recognize a-f.