Bash - Log to Screen and File Simultaneously

The Problem

In my bash script, I would like to print both the the standard output (typically the screen) and a file.

The Solution

Below is a simple script which demonstrate the solution.

#!/bin/sh

# whatis: Demo script that prints to both screen and a file

{
    echo Logging demo
    echo Output will go both the screen and logging.log
    # Other lines which might produce output here
    
} | tee logging.log

Discussion

Normally, the output from a bash script goes to the standard output, typically the screen. To redirect the output to both the standard output and a file, we employ the tee program. By surrounding the block of code with curly braces, we redirect the whole block, not just individual lines.

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