Re: no exit status available when a command doesn't exist or fails in pipe to grep

[arnold]

Ed Morton <mortoneccc@comcast.net> wrote:

> I know this is a gawk mailing list but I don't suppose you know of a 
> POSIX equivalent?
>
>     $ awk --posix 'BEGIN{cmd="garbage"; (cmd | getline); print close(cmd)}'
>     sh: garbage: command not found
>     0

POSIX merely says that 

| close(expression)
|     Close the file or pipe opened by a print or printf statement or a
|     call to getline with the same string-valued expression. The limit on
|     the number of open expression arguments is implementation-defined. If
|     the close was successful, the function shall return zero; otherwise,
|     it shall return non-zero.

This is fairly vague.  I think you're getting zero because the
underlying pclose() (or equivalent code) succeeds, even thogh the
command itself failed.

Different awks do different things here:

$ mawk 'BEGIN{cmd="garbage"; (cmd | getline); print close(cmd)}'
/bin/sh: 1: garbage: not found
127

$ nawk 'BEGIN{cmd="garbage"; (cmd | getline); print close(cmd)}'
sh: 1: garbage: not found
0

I think you're just SOL on this one.

Arnold