🔅 Linux System Engineer: Bash Shell Scripting for Automation

🌐 Author: Grant McWilliams
🔰 Level: Intermediate

⏰ Duration: 57m

🌀 Learn how to use bash scripting to automate common tasks on Linux.

📗 Topics: Bash, Linux, Shell Scripting

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📚 Loops in bash scripting

In Linux, the pipe(|) operator is very useful if you want to redirect the output of one command to serve as input to the next for further processing:

$ cat data.txt | grep "No such file"

However, this does not redirect the errors. So, if the file does not exist, the grep command above will not return a match.

What if you want to redirect and process both errors and normal output🤔

This is where this "|&" redirection operator comes in handy.

This operator sends both the standard output (stdout) and standard error (stderr) of the first command over a pipe to the standard input (stdin) of the second command. Take a look at this example:

$ cat data.txt |& grep "No such file"

Notice the difference, the grep command was able to get a match.

The "|&" operator in bash is a shorthand for the "2>&1 |" redirection operator.

$ cmd-1 2>&1 | cmd-2