Hash NRICs in files with SHA256
First, make the script executable:
chmod +x hash_nric.sh
To hash a file sample.txt containing NRICs, execute the following:
./hash_nric.sh sample.txt
This will produce a file hashed_sample.txt in the same directory as sample.txt but NRICs are replaced with their SHA256 hashes. The prefixed "hashed_" is fixed.
If you want a different name for the output file, then:
./hash_nric.sh sample.txt newname.txt