Path: utzoo!attcan!uunet!auspex!guy
From: guy@auspex.UUCP (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: Echo
Message-ID: <723@auspex.UUCP>
Date: 15 Dec 88 19:34:22 GMT
References: <6557@june.cs.washington.edu> <960@etnibsd.UUCP> <3331@mipos3.intel.com>
Reply-To: guy@auspex.UUCP (Guy Harris)
Organization: Auspex Systems, Santa Clara
Lines: 37

>Will it not work to do ...
>
>PATH=/usr/5bin:$PATH echo "\tthis is a test\n"
>
>... since PATH will be different for the execution of only the "echo"
>command?

Yes, it'll work, at least under SunOS 4.0, *but* it also sets PATH
within the shell that you're running! The problem is probably that
"echo" is a built-in, so no child process is spawned to run it, and thus
the PATH-mashing is done in the process running the main shell. 

I don't have a vanilla S5 system on which to try this (it won't change
the behavior of "echo", but it should test whether PATH gets smashed or
not), and some amount of environment-fiddling was changed around a bit
in SunOS 4.0 to fix another bug, so I don't know if the bug is Sun's or
AT&T's.

Doing

	(PATH=/usr/5bin:$PATH echo "\tthis is a test\n")

provides a workaround; this also "does what you want", at least under
SunOS 4.0, and doesn't smash PATH; the parentheses force the "echo" to
be done in a subshell, and probably forces PATH to be modified there as
well.

>Also, your second line *expands* PATH, and doesn't set it.

Yes, but sticking "/usr/5bin" at the front is sufficient for his purposes.

This may all be fixed in S5R4, if it has the Korn shell; I think the
"print" command can be made to either behave like the V7 "echo", behave
like the S3/S5 "echo", or exhibit other behavior (I think that in the
Korn shell "echo" is set up as an alias for "print" with some particular
options - in the later versions, I think it checks where "echo" would be
found given the value of PATH and sets up the alias appropriately).