Re: how to search for a substring in a parameter?

[Peter Stephenson <pws@xxxxxxx>]

Carlos Carvalho wrote:
> I'm trying to see if the value of a parameter contains a given string
> but didn't find an elegant way.

What was wrong with

if [[ $foo = *pattern* ]]; then
  ...

?  The patterns are identical to those in parameter substitution.

> All pattern matching substitutions
> return only the non-matched portion of the value.

You can use the flags M for the matched portion combined with either
head or tail matching using the S flag to tell it to match substrings,
i.e. anywhere in the pattern.

% foo='this is a pattern, too'
% print ${(MS)foo##pattern}
pattern

The M flag doesn't work with the `/' or `//' substitutions (and the S
flag is differnt --- it forces the shortest match).  Not clear
if that's `really' a bug, but it does agree with the documentation.

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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