Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!husc6!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Is There A Way To Check If argv[1] Is An Integer?
Message-ID: <15494@haddock.ima.isc.com>
Date: 20 Dec 89 23:16:33 GMT
References: <984@ux.acss.umn.edu> <11467@csli.Stanford.EDU>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 13

In article <11467@csli.Stanford.EDU> poser@csli.stanford.edu (Bill Poser) writes:
>In article <984@ux.acss.umn.edu> eric@ux.acss.umn.edu (Eric D. Hendrickson)
>writes the equivalent of:
>int is_integer(char *s) { return(regexec(regcomp("[-+]?[0-9]+"),s)); }

I think regexp is a bit of overkill; I generally use strtol() for this.
(Usually, once you've detected that the argument is in fact an integer, you
need to evaluate it anyway, right?)

And if you're on a backward system that doesn't have strtol(), it's not hard
to write one.  Compared to regexp, for instance.

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint