Bash Replace String Code Example

Example 1: bash replace substring

echo [string] | sed "s/[original]/[target]/g"

Example 2: bash script: replace . with :

#To replace the first occurrence of a pattern with a given string, #use ${parameter/pattern/string}:  #!/bin/bash firstString="I love Suzi and Marry" secondString="Sara" echo "${firstString/Suzi/$secondString}"      # prints 'I love Sara and Marry'  #To replace all occurrences, use ${parameter//pattern/string}:  message='The secret code is 12345' echo "${message//[0-9]/X}"            # prints 'The secret code is XXXXX'   #(This is documented in the Bash Reference Manual, §3.5.3 "Shell Parameter Expansion".)

Example 3: bash replace substring in string

#!/bin/bash firstString="I love Suzi and Marry" secondString="Sara" echo "${firstString/Suzi/$secondString}"     # prints 'I love Sara and Marry'

Example 4: bash replace beginning of string

$ cat shortest.sh #! /bin/bash  filename="bash.string.txt"  echo ${filename#*.} echo ${filename%.*}  $ ./shortest.sh After deletion of shortest match from front: string.txt After deletion of shortest match from back: bash.string

Example 5: bash search and replace text in file

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