Re: nc -w with -z does not seems to work.
2009/1/30 jared r r spiegel j...@ice-nine.org: check the obsd manpage, it is specifically different and does not mention connects:' But nc -h gives -w secs Timeout for connects and final net reads So I guess obsd nc does not support timeouts for connect and will wait 1m15sec if host is not up? raj
Re: nc -w with -z does not seems to work.
On Fri, Jan 30, 2009 at 01:34:51PM +0530, Rajkumar S wrote: 2009/1/30 jared r r spiegel j...@ice-nine.org: check the obsd manpage, it is specifically different and does not mention connects:' But nc -h gives -w secs Timeout for connects and final net reads yup, you're right. other than the uppercase 'T' that's the same string as in the netcat i have on a debian system. i'd guess that the obsd help() might just need an update to make it consistent with the manpage. it's possible that *i* am just misunderstanding the obsd nc(1), but in my experience, the timeout given by -w has nothing to do with connect timeouts. So I guess obsd nc does not support timeouts for connect and will wait 1m15sec if host is not up? the wait is probably whatever the underlying network stack would normally have: /home/jrrs $ time telnet 1.2.3.4 23 Trying 1.2.3.4... telnet: connect to address 1.2.3.4: Connection timed out 1m15.03s real 0m0.01s user 0m0.00s system -- jared
Re: nc -w with -z does not seems to work.
On Thu, Jan 29, 2009 at 12:26:21PM +0530, Rajkumar S wrote: Help says -w is timeout for connects and final net reads, so nc should exit after 2 seconds, and it does exit when tested under linux, but not under openbsd. check the obsd manpage, it is specifically different and does not mention connects:' --- -w timeout If a connection and stdin are idle for more than timeout seconds, then the connection is silently closed. The -w flag has no ef- fect on the -l option, i.e. nc will listen forever for a connec- tion, with or without the -w flag. The default is no timeout. --- it is only for idles Am i doing some thing wrong or is this a bug in nc ? the gnu nc is different than the obsd one, even tho they're (iirc) both derived from the same source a while ago. the one in gnu land's -w option does what you want regarding connect timeouts. the openbsd one does not. -- jared
nc -w with -z does not seems to work.
Hi, I am using Openbsd 4.4 GENERIC#1021 and nc to check if a port is open or not. The command I use is # /usr/bin/nc -z -w 2 192.168.1.10 80 The command works fine if 192.168.1.10 is up, but if ip is non existing it takes about 1m15sec to exit. # time /usr/bin/nc -v -z -w 2 192.168.3.96 80 nc: connect to 192.168.3.96 port 80 (tcp) failed: Connection timed out 1m14.99s real 0m0.00s user 0m0.00s system Help says -w is timeout for connects and final net reads, so nc should exit after 2 seconds, and it does exit when tested under linux, but not under openbsd. Am i doing some thing wrong or is this a bug in nc ? raj
