How to Create Custom Header Template for Shell Scripts in Vim

First start by creating the template file called sh_header.temp, which contains your custom bash script header, possibly under ~/.vim/ directory under your home.

$ vi ~/.vim/sh_header.temp

Next add the following lines in it (feel free to set your own template file location and custom header) and save the file.

Custom Header Template for Scripts

#!/bin/bash 

###################################################################
#Script Name	:                                                                                              
#Description	:                                                                                 
#Args           	:                                                                                           
#Author       	:Aaron Kili Kisinga                                                
#Email         	:[e-mail]                                           
###################################################################

Create Custom Header Template for Scripts

ایجاد منو در شل اسکریپت

#!/bin/bash
# A menu driven shell script sample template 
## ----------------------------------
# Step #1: Define variables
# ----------------------------------
EDITOR=vim
PASSWD=/etc/passwd
RED='\033[0;41;30m'
STD='\033[0;0;39m'
 
# ----------------------------------
# Step #2: User defined function
# ----------------------------------
pause(){
  read -p "Press [Enter] key to continue..." fackEnterKey
}

one(){
	echo "one() called"
        pause
}
 

Generate random number from a range in a Bash Script

shuf -i 2000-65000 -n 1

Enjoy!

Edit: The range is inclusive.

How to comment multiple lines at once in VIM

For commenting a block of text is almost the same: First, go to the first line you want to comment, press CtrlV, and select until the last line. Second, press ShiftI#Esc (then give it a second), and it will insert a # character on all selected lines.

Echo tab characters in bash script

echo -e ' \t '

will echo 'space tab space newline' (-e means 'enable interpretation of backslash escapes'):

$ echo -e ' \t ' | hexdump -C
00000000  20 09 20 0a   

How to Import a Variable from a Script?

# a.sh
num=42

# b.sh
. ./a.sh
echo $num

The variables in "a" do not need to be exported.

How can I make bash my login shell?

if your login shell is csh or tcsh, and you have installed

bash in /usr/gnu/bin/bash, add the following line to ~/.login:



	if ( -f /usr/gnu/bin/bash ) exec /usr/gnu/bin/bash --login

Bash tips: Colors and formatting

The ANSI/VT100 terminals and terminal emulators are not just able to display black and white text ; they can display colors and formatted texts thanks to escape sequences. Those sequences are composed of the Escape character (often represented by ”^[” or ”<Esc>”) followed by some other characters: ”<Esc>[FormatCodem”.

In Bash, the <Esc> character can be obtained with the following syntaxes:

• \e
• \033
• \x1B

Examples:

Code (Bash)	Preview
echo -e "\e[31mHello World\e[0m"
echo -e "\033[31mHello\e[0m World"

NOTE¹: The -e option of the echo command enable the parsing of the escape sequences.

NOTE²: The ”\e[0m” sequence removes all attributes (formatting and colors). It can be a good idea to add it at the end of each colored text. ;)

NOTE³: The examples in this page are in Bash but the ANSI/VT100 escape sequences can be used in every programming languages.