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Tutorial10: Shell Scripting - Part 1

12 bytes added, 16 March
# Save your editing session and exit the text editor<br>(eg. with vi: press '''ESC''', then type ''':wx''' followed by '''ENTER''').<br><br>[[Image:if-2.png|thumb|right|320px|Output of a shell script using the '''read''' command and the '''if''' control-flow statement.]]
# Issue the following Linux command to add execute permissions for your shell script:<br><span style="color:blue;font-weight:bold;font-family:courier;">chmod u+x if-2.bash</span><br><br>
# Run your shell script by issuing:<br><span style="color:blue;font-weight:bold;font-family:courier;">./if-2.bash</span><br><br>Confirm that Enter the first number greater than the output indicated a correct result.second number<br><br>What happens when you Run the script again and enter a first number that is less than or equal to the second number? <br><br>Let's use an '''if-else''' statement to provide an appropriate alternative<br>if the condition is FALSE.<br><br>
# Use a text editor like vi or nano to create the text file called '''if-3.bash''' (eg. <span style="color:blue;font-weight:bold;font-family:courier;">vi if-3.bash</span>)<br><br>
# Enter the following lines in your shell script:<br><span style="font-family:courier;font-weight:bold">#!/bin/bash<br>read -p "Enter the first number: " num1<br>read -p "Enter the second number: " num2<br>if [ $num1 -gt $num2 ]<br>then<br>&nbsp;&nbsp;&nbsp;echo "The first number is greater than the second number."<br>else<br>&nbsp;&nbsp;&nbsp;echo "The first number is less than or equal to the second number."<br>fi</span><br><br>