Re: PS1 prompt problem

[Andreas Schwab]

Nils <nils.bernhard@yahoo.de> writes:

> Following a suggestion in comp.unix.shell putting the above code
> contained in $() inside a separate function f and setting PS1='$( f )'
> displays the $spwd correctly in both the prompt and xterm title, but
> bash escapes like "\u", "\h" etc are not expanded any more

You could pass them as arguments to the function.

> What's wrong here?

You are faced with multi-level expansion and need to protect the special
characters that you want to be preserved for the later levels.  Before
the command substitution is expanded all backslash sequences are
expanded, so for example "\033_%s\033\\" becomes "^[_%s^[\" (where ^[
denotes the literal escape character).  The trailing backslash is now
quoting the quote character, which results in an unmatched quote.  Thus
you should write "\\033_%s\\033\\\\" instead.

PS1='$(
    spwd="${PWD/#${HOME}/~}"
    [[ ${#spwd} -gt 10 ]] && spwd="...${spwd: -10}"
    printf "%s@%s:%s%s " "\u" "\h" "${spwd}" "\$"
    termtitle="\u@\h:${spwd}"

    ####
    printf "%s" "\["
    case "${TERM}" in
        (xterm*)
            printf "\\033]0;%s\\a" "${termtitle}"
            ;;
        (screen*)
            printf "\\033_%s\\033\\\\" "${termtitle}"
            ;;
    esac
    printf "%s" "\]"
    ####
)'

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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