Re: [bug] close() returns "0" when closing unopened files

[Aharon Robbins]

> Date: Sat, 6 Dec 2008 13:43:50 +0100
> From: Seb <address@hidden>
> To: Aharon Robbins <address@hidden>
> Cc: address@hidden
> Subject: Re: [bug] close() returns "0" when closing unopened files
>
> Oh! I forgot to notice that the returned values of close() are not documented
> in the manual.

I'm sorry, but this is incorrect. In node  Close Files And Pipes it says:

        @command{gawk} treats @code{close} as a function.
        The return value is @minus{}1 if the argument names something
        that was never opened with a redirection, or if there is
        a system problem closing the file or process.
        In these cases, @command{gawk} sets the built-in variable
        @code{ERRNO} to a string describing the problem.
        
        In @command{gawk},
        when closing a pipe or coprocess (input or output),
        the return value is the exit status of the address@hidden
        This is a full 16-bit value as returned by the @code{wait}
        system call. See the system manual pages for information on
        how to decode this value.}
        Otherwise, it is the return value from the system's @code{close} or
        @code{fclose} C functions when closing input or output
        files, respectively.
        This value is zero if the close succeeds, or @minus{}1 if
        it fails.
        
        The POSIX standard is very vague; it says that @code{close}
        returns zero on success and non-zero otherwise.  In general,
        different implementations vary in what they report when closing
        pipes; thus the return value cannot be used portably.
        @value{DARKCORNER}
        
Thanks,

Arnold