Using Comments in Bash

In Bash scripting, comments are used to annotate code, making it easier to understand and maintain. Bash supports single-line comments natively and provides workarounds for multi-line comments.

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Bash Comments

Single line

# This is a comment
echo "hello world"

Single in line comment

echo "hello world" # prints hello world
ls -lh "$dir"/* # long list all files inside $dir

Multi line comment style 1

# This is a multiline comment
# and here is line 2
# Line 3
echo "hello world"

Multi line comment - Here document

: << 'COMMENT'
This is a multi-line comment. We can add as much text as we want 
between the comment tags and it will be ignored by the shell.
COMMENT
echo "hello world"

The key word does not need to be COMMENT. It can be any string. The static part is the :, << and ' around the keyword. Here is another example:

: << 'HERE'
this is another multiline comment
See?! another line
and another line
HERE
echo "hello world"