Date: Fri, 02 Nov 2001 10:56:11 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: Fabio Miranda <fmirand@yahoo.com> Cc: freebsd-chat@FreeBSD.org Subject: RE: struct hostent Message-ID: <XFMail.011102105611.jhb@FreeBSD.org> In-Reply-To: <20011102161519.40762.qmail@web11504.mail.yahoo.com>
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On 02-Nov-01 Fabio Miranda wrote: > Hi, i am coding a small c program in order to learn > network programming: > main(int argc, char *argv[]){ > struct hostent *host; > .... > if((host=gethostbyname(argv[1])=NULL)){ > perror("gethostbyname"); > exit(-1);} This should be: if ((host = gethostbyname(argv[1])) == NULL) { Note the "==" check for NULL. You are assigning NULL to host effectively, causing your core dump. I would also persoally recommand a slightly different style, but that is a matter of personal opinion I suppose. > /* now, i want to print out all the hostent struct > information */ > printf("struct hostent{\n"); > printf("char *h_name: %s", host->h_name); > printf("char **h_aliases:%s\n", host->h_length); > printf("int h_addrtype: %d\n", host->h_addrtype); > printf("int h_length: %d\n", host->h_length); > printf("char **h_addr_list: %d\n", > host->h_addr_list); > } > } > This program core dumped, it may crash because i am > trying to print an char array (h_addr_list, right?), I > want to know how can i print all the information store > in a struct hostent?, especiality the ip address. > > thanks > > > __________________________________________________ > Do You Yahoo!? > Find a job, post your resume. > http://careers.yahoo.com > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-chat" in the body of the message -- John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
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