Category: Computers

Let’s say that you have a file and you would like to convert each line in the file to an element in an array.

The key to this is knowing about and how to manipulate the IFS (Internal Field Separator).  The default IFS is whitespace (a space, tab, or newline) and if you create an array passing it a whitespace delimited list of strings, each token will be set to an element in the array.

ARRAY=(a b d 

About a year ago I posted an article about how to split into an array of values based on a given delimiter in bash.

The following is how to take that same string and split it on the first occurrence of the same user defined delimiter.

Both use the ‘read’ command, but in a slightly different way.

Instead of passing read the -a [aname] parameter which tells it that “The words are assigned to sequential indices of the array → Continue reading “Splitting a String in Bash on the FIRST Occurrence of a Character”

Often times you will want to write a BASH script where you don’t want to have to keep track of all of the positional command line arguments and/or you might want to configure it with a set of environmental variables while having a default value for each in the script.

Following is the syntax for declaring them in the shell script, and then an example on how to invoke it.

#!/bin/bash

: ${ARG1:="somedefault_arg1"}
: ${ARG2:="10"}

echo "ARG1 = $ARG1"
echo