seg fault
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From: John Gordon on 17 May 2010 17:36 In <4bf1a10c$0$26945$bbae4d71(a)news.suddenlink.net> "Bill Cunningham" <nospam(a)nspam.invalid> writes: > Why do I keep getting a segmentation fault here? I want to write to an > echo server and receive back. Tell us what line of code generates the seg fault. Tell us what's in the mysterious header file main.h. -- John Gordon A is for Amy, who fell down the stairs gordon(a)panix.com B is for Basil, assaulted by bears -- Edward Gorey, "The Gashlycrumb Tinies"
From: Ian Collins on 17 May 2010 17:37 On 05/18/10 09:32 AM, Bill Cunningham wrote: > "David Schwartz"<davids(a)webmaster.com> wrote in message > news:cfe79619-dc92-4339-9614-b5aa0d58a434(a)v12g2000prb.googlegroups.com... > > You need to generate and analyze a core dump to make sense of the > segmentation fault. Or at least add printf's or similar commands so > you can figure out which line is faulting. > > I don't know how to do that. I'm not getting a core dump. Should I > generate one somehow? I do have gdb. So then the source code looks fine > there's just something happening somewhere? > > I don't know what a segmentation fault means though I've seen many of > them. Oh come on Bill, in you decade or so of trolling Usenet, you must had more than your fair share and worked out what they are. -- Ian Collins
From: John Gordon on 17 May 2010 17:47 In <4bf1b5cc$0$12426$bbae4d71(a)news.suddenlink.net> "Bill Cunningham" <nospam(a)nspam.invalid> writes: > I don't know how to do that. I'm not getting a core dump. Should I Is the program setuid, or are you running it in a directory where you don't have write permission? > I don't know what a segmentation fault means though I've seen many of > them. Usually it means the program tried to write to a memory location that it doesn't own, which is in turn usually caused by a null or overwritten pointer. -- John Gordon A is for Amy, who fell down the stairs gordon(a)panix.com B is for Basil, assaulted by bears -- Edward Gorey, "The Gashlycrumb Tinies"
From: Lew Pitcher on 17 May 2010 18:05 On May 17, 2010 16:03, in comp.unix.programmer, nospam(a)nspam.invalid wrote: > Why do I keep getting a segmentation fault here? I want to write to an > echo server and receive back. > > #include "main.h" > > struct addrinfo ad, *p; > > int client(char *ip, char *port) > { > int rv, c, sock; > char *buf = "hello\n"; > memset(&ad, 0, sizeof ad); > getaddrinfo(ip, port, &ad, &p); Bill... What is p pointing at? > ad.ai_family = AF_INET; > ad.ai_socktype = SOCK_STREAM; > if ((sock = socket(p->ai_family, p->ai_socktype, 0)) == -1) > return -1; > if ((c = connect(sock, p->ai_addr, p->ai_addrlen)) == -1) > return -2; > fcntl(sock, F_SETFL, O_NONBLOCK); > if ((rv = write(sock, buf, sizeof buf)) == -1) > return -3; > return 0; > } > > int main() > { > int r; > r = client(NULL, "4"); > printf("%d\n", r); > } > > > -- Lew Pitcher Master Codewright & JOAT-in-training | Registered Linux User #112576 Me: http://pitcher.digitalfreehold.ca/ | Just Linux: http://justlinux.ca/ ---------- Slackware - Because I know what I'm doing. ------
From: Lew Pitcher on 17 May 2010 18:06
On May 17, 2010 18:05, in comp.unix.programmer, lpitcher(a)teksavvy.com wrote: > On May 17, 2010 16:03, in comp.unix.programmer, nospam(a)nspam.invalid > wrote: > >> Why do I keep getting a segmentation fault here? I want to write to >> an >> echo server and receive back. >> >> #include "main.h" >> >> struct addrinfo ad, *p; >> >> int client(char *ip, char *port) >> { >> int rv, c, sock; >> char *buf = "hello\n"; >> memset(&ad, 0, sizeof ad); >> getaddrinfo(ip, port, &ad, &p); > > Bill... > > What is p pointing at? Never mind. I found it. Thanks > >> ad.ai_family = AF_INET; >> ad.ai_socktype = SOCK_STREAM; >> if ((sock = socket(p->ai_family, p->ai_socktype, 0)) == -1) >> return -1; >> if ((c = connect(sock, p->ai_addr, p->ai_addrlen)) == -1) >> return -2; >> fcntl(sock, F_SETFL, O_NONBLOCK); >> if ((rv = write(sock, buf, sizeof buf)) == -1) >> return -3; >> return 0; >> } >> >> int main() >> { >> int r; >> r = client(NULL, "4"); >> printf("%d\n", r); >> } >> >> >> > -- Lew Pitcher Master Codewright & JOAT-in-training | Registered Linux User #112576 Me: http://pitcher.digitalfreehold.ca/ | Just Linux: http://justlinux.ca/ ---------- Slackware - Because I know what I'm doing. ------ |