Function build_command_string_with 

pub fn build_command_string_with(
    argv: &[String],
    style: ShellQuotingStyle,
) -> String

Rebuild a shell command line from the argv the user typed, for a given shell dialect.

A single element is a shell script the user quoted as a whole ($ "ls | wc -l") and is kept verbatim; multiple elements were split by the outer shell, so each one is quoted to survive the inner shell unchanged.