CVS commit: src/bin/sh

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Tue Nov 16 11:28:29 UTC 2021

Modified Files:
        src/bin/sh: exec.c sh.1

Log Message:
PR bin/56491

Make "hash" exit(!=0) (ie: exit(1)) if it writes an error message to
stderr as required by POSIX (it was writing "not found" errors, yet
still doing exit(0)).

Whether, when doing "hash foobar", and "foobar" is not found as a command
(not a built-in, not a function, and not found via a PATH search), that
should be considered an error differs between shells.  All of the ksh
descendant shells say "no", write no error message in this case, and
exit(0) if no other errors occur.   Other shells (essentially all) do
consider it an error, write a message to stderr, and exit(1) when this happens.

POSIX isn't clear, the bug report:
     https://austingroupbugs.net/view.php?id=1460
which is not yet resolved, suggests that the outcome will be that
this is to be unspecified.   Given the diversity, there might be no
other choice.

Have a foot in both camps - default to the "other shell" behaviour,
but add a -e option (no errors ... applies only to these "not found"
errors) to generate the ksh behaviour.   Without other errors (like an
unknown option, etc) "hash -e anyname" will always exit(0).

See the PR for details on how it all works now, or read the updated man page.

While here, when hash is in its other mode (reporting what is in the
table) check for I/O errors on stdout, and exit(1) (with an error
message!) if any occurred.   This does not apply to output generated
by the -v option when command names are given (that output is incidental).

In sh.1 document all of this.   Also add documentation for a bunch of
other options the hash command has had for years, but which were never
documented.   And while there, clean up some other sections I noticed
needed improving (either formatting or content or both).


To generate a diff of this commit:
cvs rdiff -u -r1.56 -r1.57 src/bin/sh/exec.c
cvs rdiff -u -r1.236 -r1.237 src/bin/sh/sh.1

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.