Echo

[Dominic Dunlop]

In article <6557 at june.cs.washington.edu> ka at june.cs.washington.edu (Kenneth Almquist) writes:
>I've been implementing a public domain shell and I'm wondering what to
>do about the echo builtin...
>
>Any suggestions?  In particular I would like to know if any standards
>organizations have addressed the semantics of echo.  Does anyone know
>what the merged AT&T/SUN UNIX is going to do about echo?

Nobody in the large traffic I've seen seems to have given an explicit
answer, so I'll quote from the _UNIX System V Release 4.0 Migration
Reference Guide, UNIX System V_ distributed at the recent developer
conferences.  It's a preliminary document, and doesn't have an AT&T select
code, which means you'll almost certainly be out of luck if you try to
order yourself a copy.  But, if you want to try, AT&T's numbers are (800)
432-6600 (USA), (800) 255-1242 (Canada) and (317) 352-8557 (elsewhere).
You may at least learn when the final version will be published.
Corresponding migration guides for BSD, Sun OS, and Xenix were also
distributed at the conferences.

Anyway

echo(1)
    In release 4.0, the echo command has been enhanced to support both the
    SunOS and UNIX System V version of the command.  echo automatically
    selects between the two definitions according to the value of the PATH
    variable.  The UNIX System V definition is the default definition.
    However, if the PATH contains the entry /usr/ucb, and that entry comes
    before /usr/bin, then the SunOS version of echo is selected.

    This enhancement was made to support the transition of BSD
    applications, and may be withdrawn in UNIX System V releases beyond
    4.0.

So now you know.
-- 
Dominic Dunlop
domo at sphinx.co.uk  domo at riddle.uucp