Add ansi_strip function

README.md

@@ -211,6 +211,16 @@ tasks_run build package; # Runs the build and package tasks as above
 tasks_run $@; # Passes all arguments (except the script name / path itself) to the task runner
 ```
 
+### `ansi_strip`
+Originally from [this StackOverflow answer](https://stackoverflow.com/a/54766117/1460422), this utility function takes no arguments and simply strips all ANSI escape codes from stdin, and writes the output to stdout.
+
+Useful for writing lantern output to a target which doesn't support escape codes, such as a log file.
+
+```bash
+tasks_run ci | ansi_strip >>"${log_filename}";
+tasks_run package | ansi_strip >package.log;
+```
+
 ## Contributing
 Contributions are welcome! Simply fork this repository, make your changes, and submit a Pull Request (aka Merge Request).
 

lantern.sh

@@ -207,3 +207,15 @@ tasks_run() {
 		shift
 	done
 }
+
+# Originally from https://stackoverflow.com/a/54766117/1460422
+# Strips ANSI escape codes from stdin, and writes the output to stdout.
+# No arguments.
+ansi_strip() {
+	shopt -s extglob; # Enable Bash extended globbing expressions
+	local line
+	local IFS=
+	while read -r line || [[ "$line" ]]; do
+		echo "${line//$'\e'[\[(]*([0-9;])[@-n]/}";
+	done
+}