> The amount of shell and build scripts on Unix-likes that die horrible deaths w...

pdkl95 · on March 6, 2016

Always use "$@"

    foo() {
        for arg in "$@" ; do
            echo "arg is \"${arg}\""
        done
    }

    foo 'bar baz' 'spaces in filename.txt'

> dashes in filenames.

When writing shell scripts it's a good idea to use the -- option whenever possible

    stupid_backup() {
        cp -a -- "$@" /stupid/backup/dir/
    }
 
    # copies 2 files
    stupid_backup --files '-with -leading -dashes'

fnbr · on March 6, 2016

What does the -- option do? I haven't encountered that before.

QuercusMax · on March 7, 2016

It means "everything past here should not be parsed as a - or -- flag". If you have a file named "-l", then ls -- -l will show you that file, instead of doing a long listing.

cyphar · on March 7, 2016

It should be noted that not all flag parsers support it. But most people use getopt so it's not a big deal.

fnbr · on March 7, 2016

Thanks- that's really useful.