ksh incompatabilities with sh?

[Lawrence V. Cipriani]

In article <16183 at brl-adm.ARPA> rbj at ICST-CMR.ARPA (Root Boy Jim) writes:
	... discussion of the origin and use of ^ vs. | canned
>OK. I will grant you that `^' preceded '|'. But why do `many of (y)our
>customers still use ^ for pipes'? The original CACM paper, which I
>believe appeared in 74, predated most people's exposure to UNIX, and
>it used the symbol '|' for piping. So why would anyone have used `^'?

I suppose the ^ was considered archaic even in '74.

Our customers are phone companies and have been using our product
for over 16 years.  Many of the *users* that were involved with our
product back then are still using it.  Their exposure to UNIX predated
the CACM paper by a few years (see "Advanced UNIX Programming" by
Rochkind pg 156-157 for a brief glimpse of Columbus UNIX, which is
what several of AT&T's (older) internal products ran under).

The documentation for sh that was distributed way back showed ^ and |.
Before divesture of the RBOCS our customers could, at their option,
get source listings of our product for a modest printing fee.
They certainly are capable of understanding it, even code as obtuse as
sh.  Also, the shell scripts that were part of the product ocassionally
used ^.  The training classes might have infected them with ^.
Wherever they picked it up from, they've got and have a hard time kicking
the habit.

The ^ problem"is like the <> redirection operator.  Its not documented
but it is in most versions of the Bourne shell.  It means open for
read *and* write.  I've seen it used only once.  <> will be part of
the next ksh release.

>I can see people at TPC using `^' out of habit, but customers?

What's TPC, "The Phone Company" ?  It doesn't exist any more.

-- 
Larry Cipriani, AT&T Network Systems and Ohio State University
Domain: lvc at tut.cis.ohio-state.edu
Path: ...!cbosgd!osu-cis!tut.cis.ohio-state.edu!lvc (strange but true)