KSH substring function (is it on your system?)

[BALDWIN]

> As long as we're talking about 'substring', 'expr' has a 'substr' option
> that used to be documented in V6.
> 
> It goes:
> 	expr substr string n m
> 
> 	where n is the first character of the sub-string and m the length.
> 
> 	so:		expr substr abcdefgh 2 4
> 	gives:		bcde
> 
> 'expr' also has 'match', 'lentgh', and 'index' options that are not
> documented any longer. Anyone knows why?

The ":" operator of expr now handles all of these cases (I've never
heard of "index"; what does it do?):

-- old --				-- new --
expr match string regexp		expr string : regexp
expr length string			expr string : '.*'
expr substr string off len		expr string : '.\{off-1\}\(.\{len\}\)'

Of course, you have to make sure that "string" isn't a valid expr
operator.  Putting an ordinary char like _ at the beginning of both
the string and the regexp will fix that.
-- 
						Michael Baldwin
						{at&t}!whuxl!mike