Solaris built in command for TCP connection without all the telnet stuff

Question

Sometimes telnet is used for testing non telnet servers such as HTTP or SMTP servers where the TELNET protocol usually stays out of the way. However, I think I have run into a case where it is in the way while debugging a TCP server. I ran

telnet localhost < data_file

And the data the server receives is different than what is in the file.

Is there either an option to telnet or a whole nother command that I can use?

If it has to be installed separately, then I don't want it. I will just do without.

score 7 · Accepted Answer · answered Jul 06 '11 at 14:21

7

Well, actually it's called netcat and is Not a built-in for Solaris. But you have another option if you use bash or zsh (or may be something else):

man bash:

Bash handles several filenames specially when they are  used
in redirections, as described in the following table:
  …
     /dev/tcp/host/port
          If host is a valid hostname or  Internet  address,
          and  port  is  an  integer  port number or service
          name, bash attempts to open a  TCP  connection  to
          the corresponding socket.

answered Jul 06 '11 at 14:21

poige

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That is nice to know about `bash` and `/dev/tcp`. I don't see the capability of a two way connection though, but I expect this will be helpful down the road,, and for the more needy cases, I will just write my own script. – 700 Software Jul 06 '11 at 14:54
Excelent!! Rare knowlege – xoid May 12 '20 at 12:24

score 3 · Answer 2 · answered Jul 06 '11 at 14:13

3

I guess netcat? There's a package here. But it isn't provided by Sun default. Do you have something against packages?

answered Jul 06 '11 at 14:13

Michael Lowman

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Yes, it is temporary until a new plan is in place for server configuration management. Right now, everything needs to stay put. – 700 Software Jul 06 '11 at 14:57
IMHO, a well-documented list of installed packages will work just as well for management purposes. And I would say that the benefit of using the extensive GNU tools that aren't available in a base install on Solaris outweighs the benefits of using a completely base system. But that's definitely your choice to make :) – Michael Lowman Jul 06 '11 at 14:59

score 3 · Answer 3 · answered Nov 22 '16 at 08:35

As poige already said: You can use the /dev/tcp// device. Here is an example:

bash-3.2$ cat </dev/null >/dev/tcp/1.2.3.4/22; echo $?
0
bash-3.2$ cat </dev/null >/dev/tcp/1.2.3.4/1522; echo $?
bash: connect: Connection timed out
bash: /dev/tcp/1.2.3.4/1522: Connection timed out
1

You probably write a small bash script for this. The "timed out" message appears after TCP timeout which ich mostly set to 4 minutes. That's quite long...

score 0 · Answer 4 · answered Jul 06 '11 at 13:59

0

Maybe tcpdump? But since it is obviously not important...

answered Jul 06 '11 at 13:59

Sven

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I guess your haven't attentively read the question. – poige Jul 06 '11 at 14:17

Solaris built in command for TCP connection without all the telnet stuff

4 Answers4