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Tutorial11: Shell Scripting - Part 1

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# Issue the following linux command to '''add''' execute permissions for your shell script: chmod u+x hello

# Issue the following to run your shell script: ./hello Did your shell script run?

# Issue the following Linux command to run a checking script: ~uli101/~~week10~~week11-check-1

# If you encounter errors, make corrections and '''re-run''' the checking script until you receive a congratulations message, then you can proceed.

::In the next investigation, you will learn to create and run shell scripts that use '''variables''', '''positional''' and '''special parameters'''. You will also learn how to add a '''she-bang line''' at the top of a shell script to force it to run in a specified shell. Proceed to the next investigation.

# Exit your Matrix session, and log back into your Matrix session.

# Re-run the '''hello.bash''' shell script by just using the name. What did you notice? The setting of the '''PATH''' environment variable only worked in the current session only. If you exit the current Matrix session, then the recently changed settings for environment variables will be lost. You will in a future tutorial how to set environment variables in '''start-up''' files.

# Issue the following Linux command to run a checking script: ~uli101/~~week10~~week11-check-2 | more If you encounter errors, make corrections and '''re-run''' the checking script until you receive a congratulations message, then you can proceed. Unlike '''Environment variables''' that are used to set the environment of the shell or shell scripts, '''User-created''' variables are "customized" that the user can set or allow a user to set the variables' values. Let's create a Bash shell script that contain '''user-created variables'''.

# Use a text editor to create a Bash shell script called '''user-variables.bash'''

# Add the following lines to the beginning of the ''user-variables.bash'' file: #!/bin/bash read -p "Enter your Full Name: " name read -p "Enter your age (in years): " age echo "Hello $name - You are $age years old"

# Issue the '''chmod''' command to add execute permissions for the user for the '''dog-years.bash''' file.

# Issue the following to run the '''dog-years.bash''' Bash shell script: ./dog-years.bash Enter your age to see what happens.

# Issue the following to run a checking script: ~uli101/~~week10~~week11-check-3 | more If you encounter errors, make corrections and '''re-run''' the checking script until you receive a congratulations message, then you can proceed.

:In the next investigation, you will use '''control-flow statements''' to allow your shell scripts to perform differently under different situations.

# Issue the following Linux command to add execute permissions for your shell script: chmod u+x for-2.bash [[Image:for-2.png|thumb|right|175px|Output of a shell script using the '''for''' loop without a '''list'''.]]

# Run your shell script by issuing: ./for-2.bash 10 9 8 7 6 5 4 3 2 1 How does this differ from the previous shell script? You will learn in a couple of weeks more examples of using loop statements. Let's run a '''checking-script''' to confirm that both your '''for-1.bash''' and '''for-2.bash'''

# Issue the following Linux command to run a checking script: ~uli101/~~week10~~week11-check-4 | more If you encounter errors, make corrections and '''re-run''' the checking script until you receive a congratulations message, then you can proceed.

= LINUX PRACTICE QUESTIONS =

Msaul

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Tutorial11: Shell Scripting - Part 1

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