NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/comp/lang/c/17054

Text File | 1992-11-23 | 1.0 KB | 30 lines

Organization: Applications Software, Carnegie Mellon, Pittsburgh, PA
Path: sparky!uunet!cis.ohio-state.edu!news.sei.cmu.edu!fs7.ece.cmu.edu!crabapple.srv.cs.cmu.edu!andrew.cmu.edu!rr2p+
Newsgroups: comp.lang.c
Message-ID: <[e-mail]>
Date: Mon, 23 Nov 1992 13:50:46 -0500
From: Richard Dale Romero <[e-mail]>
Subject: Re: Multiple &'s in an if statement
In-Reply-To: <1992Nov23.164530.19214@iacd>
References: <1992Nov23.164530.19214@iacd>
Distribution: comp.lang.c
Lines: 17

Probably because you're using bit-wise and instead of logical and.
In C, a zero is false and anything else is true.  There is no specification
for what (x == y) returns other than zero or not zero.  So, suppose
that isdigit returns a 2 everytime for true, and
(iscntrl(name[(strlen(path) + 5)]))
returns a 1.  Their bitwise and is 0, ie, false.

So, to make it work, just do the following:

if(( isdigit[i] & isdigit[i+1] & isdigit[i+2] & isdigit[i+3] & isdigit[i+4])
   && (name[(strlen(path)+5)] == NULL)) {
...
}

-rick