ShellWords

Parse a string into words, like a shell would.

Motivation

If you need to execute commands given to you as user-input, you should know not to give that text as-is to a shell:

callProcess "sh" ["-c", "some --user --input"]

Such code is a severe security vulnerability. Furthermore, any attempts to sanitize the string are unlikely to be 100% affective and should be avoided. The only safe way to do this is to not use a shell intermediary, and always exec a process directly:

callProcess "some" ["--user", "--input"]

The new problem (and not a security-related one) is how to correctly parse a string like "some --user --input" into the command and its arguments. The rules are complex enough that you probably want to get a library to do it.

So here we are.

Example

Right (cmd:args) <- parse "some -complex --command=\"Line And\" 'More'"

callProcess cmd args
--
-- Is equivalent to:
--
-- > callProcess "some" ["-complex", "--command=Line And", "More"]
--

Lineage

This package is inspired by and named after

• python-shellwords, which was itself inspired by
• go-shellwords, which was itself inspired by
• Parser::CommandLine

CHANGELOG | LICENSE