Function uucore::backup_control::determine_backup_suffix

pub fn determine_backup_suffix(matches: &ArgMatches<'_>) -> String

Obtain the suffix to use for a backup.

In order of precedence, this function obtains the backup suffix

1. From the ‘-S’ or ‘–suffix’ CLI argument, if present
2. From the “SIMPLE_BACKUP_SUFFIX” environment variable, if present
3. By using the default ‘~’ if none of the others apply

This function directly takes clap::ArgMatches as argument and looks for the ‘-S’ and ‘–suffix’ arguments itself.