Unrecognized Escape Sequence

Obligatory xkcd on the difficulties working with archives in Linux:

For most cases, the following function can be plonked into your .bashrc or .zshrc etc. to make extracting files a little easier.

# ------------------------------------------------------------------------------------------
# Extract function
# ------------------------------------------------------------------------------------------

function extract() {
    if [ -f "$1" ] ; then
        case "$1" in
            *.tar.bz2)   tar xvjf "$1"                    ;;
            *.tar.gz)    tar xvzf "$1"                    ;;
            *.bz2)       bunzip2 "$1"                     ;;
            *.rar)       unrar x "$1"                     ;;
            *.gz)        gunzip "$1"                      ;;
            *.tar)       tar xvf "$1"                     ;;
            *.tar.xz)    tar xvf "$1"                     ;;
            *.tbz2)      tar xvjf "$1"                    ;;
            *.tgz)       tar xvzf "$1"                    ;;
            *.zip)       unzip "$1"                       ;;
            *.ZIP)       unzip "$1"                       ;;
            *.pax)       cat "$1" | pax -r                ;;
            *.pax.Z)     uncompress "$1" —stdout | pax -r ;;
            *.Z)         uncompress "$1"                  ;;
            *.7z)        7z x "$1"                        ;;
            *)           echo "don't know how to extract '$1'..." ;;
        esac
    else
        echo "extract: error: $1 is not valid"
    fi
}