×
INTELLIGENT WORK FORUMS
FOR COMPUTER PROFESSIONALS

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

problem with ssh not returning

problem with ssh not returning

problem with ssh not returning

(OP)
I am currently porting some legacy code into a new scheduling system. It runs on a number of source servers and invokes the following on a number of target servers. All servers are running  Solaris 10.

The command at issue is:

CODE

ssh -o "BatchMode=yes" ${TARGET_USER}@${TARGET_HOST} "${TEST_SCRIPT} </dev/null 2>&1 | egrep ^${TEST_RESULT}$ >/dev/null 2>&1"
The $? return value for this command is then tested for success before continuing the processing.

What seems to be happening, on some but not all server combinations, is that the remote script is executed and egrep succeeds (I changed the last /dev/null to /var/tmp/x to check), but the sshd process at the target end, and the ssh at source remain without terminating.

I understand that there is an issue with sshd not terminating until it receives EOF, but the suggested workaround (cf. https://bugzilla.mindrot.org/show_bug.cgi?id=52) is to re-direct output to /dev/null, which I think I'm already doing.

Am I missing something? Is there anything aside from the EOF not being received that might cause this behaviour?

RE: problem with ssh not returning

(OP)
The solution seems to have been to add the -n flag to the ssh call, so presumably it was the input channel that was still deemed open.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members! Already a Member? Login

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close