trim whitespace between string bash code example

Example 1: bash how to remove all whitespace from a file

# Example usage:
awk '{gsub(" ","",$0); print $0;}' input_file
# This replaces every space " " with nothing "", thereby eliminating all
# whitespace from the file

# Basic syntax:
awk '{gsub(regex, substitution_text, $field#); print $0;}' input_file
# Where:
#	- gsub is a function that replaces every regular expression (regex)
#		match with substitution_text. 
#	- $field# is optional but can be used to specify a particular field
#		where gsub should operate. (This is useful if you want to 
#		restrict the substitutions to a specific column)

Example 2: how to remove every space in a string in bash

#!/bin/bash

#Make our variable
var="foo bar"

#Print it without the spaces
echo ${var//[[:blank:]]/}

#Output will be foobar