Re: redirection / process substitution fails to read a file descriptor

[Chet Ramey]

On 11/17/24 6:25 PM, Robert Elz wrote:

> The use for testing for errors is also occasionally useful - a redirection
> error will cause the shell to exit (non-interactive shell) so <file can
> be a kind of shortcut for
>         test -r file || { printf >&2 message; exit 2; }
> (or similar) (and output directions test that the file either exists or
> can be created, and is writeable).

No, it usually doesn't. If a redirection error occurs with a special
builtin, POSIX says a non-interactive shell should exit. However,
just running

< file

where file doesn't exist or isn't readable, won't cause a non-interactive
shell to exit.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/

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