How to remove the `#` and `;` comments and empty lines from a configuration file?

Unix Bash
, , ,
1

The current solution (2025-03-26)

sed -i -r \
	-e '/^[[:space:]]*[#;]/d' \
	-e '/^[[:space:]]*$/d' \
	<file> &&
sed -i -z 's/\n$//' <file>

How to remove the trailing newline (LF) character (the terminal newline, the EOF newline) from a text file using sed?

The previous solution

sed -i -r '/^[\s\t]*[#;]/d' <file>
# 2024-07-28
# The previous command does not remove comments from lines indented with spaces (for an unknown reason).
# So I remove these comments using another command below.
sed -i -r '/^\s+[#;]/d' <file>
sed -i -r '/^\s*$/d' <file>
2

See also: How to remove comments and empty lines from a php.ini?

3

For all files (matching a pattern) in the current folder and subfolders:

The current solution (2025-03-26)

find . \( -name '*.conf' -o -name '*.ini' \) -type f \
	-exec sed -i -r \
		-e '/^[[:space:]]*[#;]/d' \
		-e '/^[[:space:]]*$/d' \
		{} + \
	-exec sed -i -z 's/\n$//' {} +

How to remove the trailing newline (LF) character (the terminal newline, the EOF newline) from a text file using sed?

The previous solution

find . -name '*.conf' -type f -exec sed -i -r '/^[\s\t]*[#;]/d' {} +
# 2024-07-28
# The previous command does not remove comments from lines indented with spaces (for an unknown reason).
# So I remove these comments using another command below.
find . -name '*.conf' -type f -exec sed -i -r '/^\s+[#;]/d' {} +
find . -name '*.conf' -type f -exec sed -i -r '/^\s*$/d' {} +