Bash Quick Start Guide

Reading data line by line

We mentioned earlier in this chapter that for loops are often misused to read data line by line from files, or from the output of command pipes. The correct way to do this is with a very common idiom for use with while loops: repeatedly running the read command, always with its -r flag.

Consider a file named fcs, with the names of four famous computer scientists, one on each line:

Ken Thompson
Dennis Ritchie
John McCarthy
Larry Wall

We'd like a program to print out this table, but also to print a link to the person's article on the English-language Wikipedia after each line. There is no dedicated UNIX tool to do this, so we will write our own in Bash.

We might implement a rough version something like this:

#!/bin/bash ...