Shell steps (sh, bat) in Jenkins - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the sh step in a Jenkins pipeline?

The sh step runs shell commands on Unix/Linux agents within a Jenkins pipeline.

beginner

How do you run a batch script on a Windows agent in Jenkins pipeline?

Use the bat step to run batch commands or scripts on Windows agents.

beginner

What is the difference between sh and bat steps in Jenkins?

sh runs shell commands on Unix/Linux agents, while bat runs batch commands on Windows agents.

intermediate

How can you capture the output of a shell command in Jenkins pipeline using sh?

Use def output = sh(script: 'command', returnStdout: true).trim() to capture and trim the output.

intermediate

What happens if a command run by sh or bat fails in Jenkins pipeline?

The pipeline step fails and the build stops unless you handle errors explicitly.

Which Jenkins pipeline step runs shell commands on Linux agents?

A cmd

B bat

C powershell

D sh

The sh step is used to run shell commands on Unix/Linux agents.

Which step should you use to run Windows batch commands in Jenkins pipeline?

A sh

B bat

C bash

D shell

The bat step runs batch commands on Windows agents.

How do you get the output of a shell command in Jenkins pipeline?

A bat(script: 'cmd', returnOutput: true)

B sh('cmd')

C sh(script: 'cmd', returnStdout: true)

D bat('cmd')

Use sh(script: 'cmd', returnStdout: true) to capture output from shell commands.

What happens if a shell command fails in Jenkins pipeline without error handling?

A The pipeline step fails and build stops

B The pipeline continues

C The command is retried automatically

D The error is ignored

By default, a failed shell or batch command causes the pipeline step to fail and stops the build.

Which of these is NOT a valid Jenkins pipeline shell step?

A cmd

B bat

C powershell

D sh

cmd is not a Jenkins pipeline step; use bat for Windows batch commands.

Explain how to run shell commands on Linux and batch commands on Windows in Jenkins pipelines.

Think about the agent OS and matching step.

Describe how to capture the output of a shell command in Jenkins pipeline and why it might be useful.

Focus on the <code>sh</code> step options.

Practice

1. In Jenkins pipelines, which shell step should you use to run a command on a Linux agent?

easy

A. bat

B. sh

C. cmd

D. powershell

Solution

1. Step 1: Understand Jenkins shell steps

   Jenkins uses sh to run shell commands on Linux/macOS agents.

2. Step 2: Identify the correct shell for Linux

   Since Linux uses bash or sh shells, sh is the correct step.

3. Final Answer:

   sh -> Option B

4. Quick Check:

   Linux shell step = sh [OK]

Hint: Use sh for Linux/macOS, bat for Windows agents [OK]

Common Mistakes:

• Using bat on Linux agents
• Confusing cmd with sh
• Using powershell on non-Windows agents

2. Which of the following is the correct syntax to run a Windows batch command in a Jenkins pipeline?

easy

A. sh 'dir'

B. cmd 'dir'

C. powershell 'dir'

D. bat 'dir'

Solution

1. Step 1: Identify Windows shell step in Jenkins

   Jenkins uses bat to run Windows batch commands.

2. Step 2: Match syntax for batch command

   The correct syntax is bat 'command', so bat 'dir' is correct.

3. Final Answer:

   bat 'dir' -> Option D

4. Quick Check:

   Windows batch command = bat [OK]

Hint: Use bat for Windows commands in Jenkins pipelines [OK]

Common Mistakes:

• Using sh for Windows commands
• Using cmd which is not a Jenkins step
• Using powershell without proper syntax

3. What will be the output of this Jenkins pipeline snippet on a Linux agent?

sh 'echo Hello Jenkins'

medium

A. Hello Jenkins

B. sh: command not found

C. echo Hello Jenkins

D. Syntax error

Solution

1. Step 1: Understand the sh step execution

   The sh step runs the command inside quotes on the Linux shell.

2. Step 2: Predict command output

   The command echo Hello Jenkins prints the text 'Hello Jenkins' to the console.

3. Final Answer:

   Hello Jenkins -> Option A

4. Quick Check:

   sh echo outputs text [OK]

Hint: sh runs commands and prints their output on Linux [OK]

Common Mistakes:

• Expecting the command itself as output
• Confusing syntax error with correct command
• Assuming sh step fails on Linux

4. You wrote this Jenkins pipeline step:

bat 'echo Hello from Linux'

But it runs on a Linux agent and fails. What is the problem?

medium

A. bat is for Windows, not Linux

B. echo command is invalid

C. Missing quotes around command

D. Pipeline syntax error

Solution

1. Step 1: Identify shell step and agent OS mismatch

   The bat step runs Windows batch commands, but the agent is Linux.

2. Step 2: Understand why failure occurs

   Linux agents do not support bat, so the step fails.

3. Final Answer:

   bat is for Windows, not Linux -> Option A

4. Quick Check:

   bat step on Linux = failure [OK]

Hint: Match shell step to agent OS: bat=Windows, sh=Linux [OK]

Common Mistakes:

• Thinking echo is invalid on Linux
• Assuming quotes cause error
• Blaming pipeline syntax instead of shell step

5. You want to write a Jenkins pipeline that runs a shell command on both Windows and Linux agents. Which approach is best?

hard

A. Use sh step for all agents

B. Use bat step for all agents

C. Use sh for Linux and bat for Windows with if condition

D. Use powershell step for all agents

Solution

1. Step 1: Recognize OS differences in shell steps

   Linux agents require sh, Windows agents require bat.

2. Step 2: Use conditional logic in pipeline

   Use an if condition to detect OS and run the correct shell step.

3. Final Answer:

   Use sh for Linux and bat for Windows with if condition -> Option C

4. Quick Check:

   Conditional shell steps match OS [OK]

Hint: Use if condition to select sh or bat by OS [OK]

Common Mistakes:

• Using one shell step for all OSes
• Ignoring agent OS detection
• Using powershell without Windows-only context