Better shell_quote() function for included shellquote.awk

[Nikita Zlobin]

I could not find, how to submit via savannah, so sending there.
Current shell_quote() code, posted in info docs and available for include, 
seems a bit primitive. I enhanced it for minimized quoting, as I would do when 
e.g. inlining long awk code in shell script. My version uses greedy regexp for 
separators, thus requiring to get separators array from split().
 
##########################
function shell_quote(s,    # parameter
    Q,q,b, n,i, X,S, ret)  # locals
{
    if (! s)
        return "''"
 
    Q = "\x27"  # single quote
    q = "\x22"  # double quote
    b = "\x5c"  # backslash
    n = split(s, X, "([^" q b b "]*" Q "+[^" q b b "]*)+", S)
 
    for (i = 1; ;i++) {
        if (X[i])
            ret = ret Q X[i] Q
        if (i == n)
            break
        ret = ret q S[i] q
    }
    return ret
}
##########################
 
--
Nikita Zlobin