Module shell 

Safe argument quoting for remote shell commands.

Every path or user-supplied string that is about to be interpolated into a POSIX shell command must go through quote to defeat argument splitting, globbing, and command injection. A filename containing ' or ; or $( is otherwise a direct RCE against the remote host.

Functions

quote

Wrap s in single quotes, escaping any embedded single quotes using the portable POSIX idiom '\''. Always returns a quoted string, even for the empty string — callers should never concatenate unquoted.

validate_pid

Validate that s is a plain decimal integer in 1..=u32::MAX, suitable for use as a PID. Returns the original string if valid.

validate_signal

Validate a POSIX kill signal. Accepts a numeric signal in 1..=64 or one of the common signal names. Returns the canonical form to interpolate directly.