Executing Shell Scripts in Workflow

Running a series of shell commands directly in a workflow can quickly become messy. By placing your commands in a standalone script file and invoking it in one step, you maintain a clean, maintainable workflow.

Step	Description	File/Command
1	Create the shell script	`ascii-script.sh`
2	Show a failing workflow (permission error)	`./ascii-script.sh`
3	Update workflow to grant execute rights	`chmod +x ascii-script.sh`
4	Verify successful run	Actions → Logs

1. Create the Shell Script

In your repository root, add a file named ascii-script.sh:

#!/bin/sh
sudo apt-get update -y
sudo apt-get install cowsay -y
cowsay -f dragon "Run for cover, I am a DRAGON....RAWR" >> dragon.txt
grep -i "dragon" dragon.txt
ls -ltra

Commit and push this script.

Note

Make sure your script uses a Unix-style line ending (LF) and the correct shebang (#!/bin/sh).

2. Example: Workflow Fails Due to Permissions

A minimal workflow that invokes the script directly will fail because the checked-out file isn’t executable by default:

name: Run ASCII Script

on:
  push:
    branches: [ main ]

jobs:
  ascii_job:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4

      - name: List Files Before Run
        run: ls -ltra

      - name: Run Script
        run: ./ascii-script.sh

When this runs, you'll see:

/home/runner/work/_temp/abcdef.sh: line 1: ./ascii-script.sh: Permission denied
Error: Process completed with exit code 126

Warning

Without executable permissions, the runner cannot invoke your script. Always ensure your scripts are marked as executable before running.

3. Grant Execute Permissions in Workflow

Update the workflow to add a chmod +x step before executing:

name: Run ASCII Script

on:
  push:
    branches: [ main ]

jobs:
  ascii_job:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4

      - name: List Files Before Run
        run: ls -ltra

      - name: Make Script Executable and Run
        run: |
          chmod +x ascii-script.sh
          ./ascii-script.sh

Commit and push these changes to trigger a new run.

4. Verify the Workflow Run

Go to the Actions tab and select your latest workflow.
In List Files Before Run, notice ascii-script.sh is still -rw-r--r--:
```
-rw-r--r-- 1 runner docker 161 Oct 11 11:17 ascii-script.sh
```

The Make Script Executable and Run step applies chmod +x and executes the script. You’ll see:

Reading package lists...
Building dependency tree...
Reading state information...
...
Fetched 18.6 kB in 0s (177 kB/s)
Reading database...

Finally, the script’s ls -ltra shows both the executable script and generated dragon.txt:

-rwxr-xr-x 1 runner docker 161 Oct 11 11:18 ascii-script.sh
-rw-r--r-- 1 runner docker 227 Oct 11 11:18 dragon.txt

With executable permissions in place, your script will run smoothly—keeping your workflow concise and your commands centralized.

Links and References

Watch Video