Re: [RFC/PATCH 3/4v2] test-lib: provide lazy TIME_COMMAND prereq

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 16, 2012, 19:34 UTC
Message-ID: <7v8vb6rz2n.fsf@alter.siamese.dyndns.org>
In-Reply-To: <507DB39C.3080005@kdbg.org>

Johannes Sixt <j6t@kdbg.org> writes:

Show 13 quoted lines

> Am 16.10.2012 17:07, schrieb Michael J Gruber:
>> Some test want to use the time command (not the shell builtin) and test
>> for its availability at /usr/bin/time.
>> 
>> Provide a lazy prereq TIME_COMMAND which tests for $TEST_COMMAND_PATH,
>> which can be set from config.mak. It defaults to /usr/bin/time.
>
> This avoids the builtin:
>
> 	command time $that_command
>
> It works for bash, ksh, zsh, and dash (where the latter doesn't have it
> as builtin).

"command time" works but I think that is because it is not a built-in ;-)

Here is what I read in bash(1):

       command [-pVv] command [arg ...]  Run command with args
              suppressing the normal shell function lookup. Only
              builtin commands or commands found in the PATH are
              executed.

Taken together with this from "COMMAND EXECUTION":

       If the command name contains no slashes, the shell attempts
       to locate it.  If there exists a shell function by that name,
       that function is invoked as described above in FUNCTIONS.  If
       the name does not match a function, the shell searches for it
       in the list of shell builtins.  If a match is found, that
       builtin is invoked.

       If the name is neither a shell function nor a builtin, and
       contains no slashes, bash searches each element of the PATH
       for a directory containing an executable file by that name.

I suspect "command printf 'a b c\n'" would not use $HOME/bin/printf even when I have $HOME/bin early in my $PATH (nor /usr/bin/printf for that matter).