Some basic bash snippets I use to introduce shell scripting to my Linux class.

bashsnippets.sh

#!/bin/bash

# viewing environment variables
echo "The value of the home variable is: "
echo $HOME

# issue a command
echo "The output of the pwd command is: "
pwd

# that's boring, grab output and make it readable
echo "The value of the pwd command is $(pwd)"

# assign command output to a variable
output=$(pwd)
echo "The value of the output variable is ${output}"

# view data on the command line
echo "I saw $@ on the command line"

# read data from the user
echo "Enter a value: "
read userInput
echo "You just entered $userInput"

# concatenate userinput with command output
echo "Enter a file extension: "
read ext
touch "yourfile.${ext}"

# check to see if a file exists
if [ -d /etc/sysconfig ]; then
        echo "That file is there and a directory"
else
        echo "Not there or not a directory"
fi