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save script as filename.sh chmod +x filename.sh execute this command - ./filename.sh

#!/bin/bash

#! - shebang

if we not mentioning shebang we can execute it as -

image

+++

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Basic Search and Replace:

  • :%s/old/new/g
    This replaces all occurrences of "old" with "new" in the entire file without confirmation.

Search and Replace with Confirmation:

  • :%s/old/new/gc
    Adds the c flag for confirmation before each replacement. You can confirm with y (yes), n (no), a (all), q (quit), l (last), or Ctrl-E and Ctrl-Y to scroll while confirming.

Limit Replacement to a Specific Range:

  • :10,20s/old/new/g
    Replaces all occurrences of "old" with "new" only in lines 10 through 20.

  • :'<,'>s/old/new/g
    If text is selected in visual mode, this replaces all occurrences in the selected area.

Replace Only the First Occurrence in Each Line:

  • :%s/old/new/
    Omits the g flag, so only the first occurrence of "old" is replaced on each line.

Case-Insensitive Search and Replace:

  • :%s/old/new/gI
    Adds the I flag to ignore case while searching for "old".

Replacing Whole Words Only:

  • :%s/\<old\>/new/g
    This replaces only whole words "old" with "new", preventing partial matches (e.g., it will not replace "folder" if searching for "old").

Reuse the Last Search Pattern:

  • :%s//new/g
    Skips specifying the "old" pattern and reuses the last search pattern for replacement.

Use a Different Delimiter:

  • :%s#old#new#g
    Uses # as the delimiter instead of /, which can be useful when replacing strings that contain /.

These commands enhance flexibility and efficiency when using search and replace in vim.

practice-

Update the script to use 2 command line variables $1 and $2 for country and capital respectively. When the script is executed it should now print the country and its capital using the values passed in as command line arguments.

eg: ./print-capital.sh Nigeria Abuja should print Capital city of Nigeria is Abuja

echo "Capital city of $1 is $2"

/home/bob/backup-file.sh to create a backup of any given file. Update the script to use command line argument $1 for the filename to be backed up instead of the hard-coded filename.

eg: ./backup-file.sh create-and-launch-rocket should backup create-and-launch-rocket to create-and-launch-rocket_bkp

# This script creates a backup of a given file by creating a copy as bkp
# For example some-file is backed up as some-file_bkp
set -e

file_name=$1

cp $file_name ${file_name}_bkp

echo "Done"