Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!oliveb!sun!gorodish!guy
From: guy@gorodish.Sun.COM (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: Picking a character from a word
Message-ID: <50995@sun.uucp>
Date: 27 Apr 88 05:08:25 GMT
References: <13125@brl-adm.ARPA>
Sender: news@sun.uucp
Lines: 11

>    Unfortunately, "expr substr" is a BSD-ism which has yet to find its way
>    into the SVID.

> Or the manual entry.

Actually, "expr substr" is an AT&T-ism that they never documented and that they
thought better of in S3 or so and deleted.  It has the disadvantage that a
token of "substr" - or "index" or "length" - is always treated as the operator
in question, even if it's supposed to be just a string.  (Another undocumented
feature of V7's "expr" - namely the "match" prefix operator which is equivalent
to the ":" infix operator - is still around in S5, so it doesn't work as a
string.)