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From: tps@chem.ucsd.edu (Tom Stockfisch)
Newsgroups: comp.lang.c
Subject: Re: Is There A Way To Check If argv[1] Is An Integer?
Message-ID: <636@chem.ucsd.EDU>
Date: 22 Dec 89 08:30:45 GMT
References: <984@ux.acss.umn.edu> <11467@csli.Stanford.EDU>
Reply-To: tps@chem.ucsd.edu (Tom Stockfisch)
Organization: Chemistry Dept, UC San Diego
Lines: 31

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:
>>I need a way to determine if argv[1] (or any argument) is an integer.

>int
>is_integer(string)
>char *string;
>{
>   return(regexec(regcomp("[-+]?[0-9]+"),string));
>}

How about

int	/* really BOOL */
isInteger(string)
	char	*string;
{
	char	*endptr;

	(void)strtol( string, &endptr, 10 );
	return	endptr != string;
}

>(I now await flames on errors in the regular expressions.)
>							Bill

How about flames on requiring unnecessary software?

-- 

|| Tom Stockfisch, UCSD Chemistry	tps@chem.ucsd.edu