Very simple bash question.

pogeymanz · 2008-09-25 21:05:06

Long story short: I use SSH to connect to my work computer, but the connection gets dropped after a certain number of hours (It's supposed to, I just don't know why). I have some jobs that I send that take longer than the allowed time, so the solution is to use nohup:

nohup command

So that when my ssh dies, the job is still running.

But I want to have this computer chugging along all weekend with several commands. Would I do this?

nohup command1 && nohup command2 && nohup command3

Also, what if I write a very short script with all these commands in it and then just ran:

nohup script

That would be nice, but I don't know how to write a bash script at all. Do I just make a list of commands and save it as script.sh?

daf666 · 2008-09-25 21:33:14

did you try screen?

pogeymanz · 2008-09-25 22:41:55

Don't I have to have screen installed on the work computer to do what I'm doing? I don't have root privileges, so I can't install stuff.

Allan · 2008-09-25 22:50:32

pogeymanz wrote:

nohup command1 && nohup command2 && nohup command3

Untested, but I think that would fail... I would try

nohup $(command1 && command2 && command3)

pogeymanz wrote:

Also, what if I write a very short script with all these commands in it and then just ran:
nohup script
That would be nice, but I don't know how to write a bash script at all. Do I just make a list of commands and save it as script.sh?

A bash scrpit is easy...

#!/bin/bash

command1
command2
command3

pogeymanz · 2008-09-26 00:04:56

Allan wrote:

Untested, but I think that would fail... I would try
nohup $(command1 && command2 && command3)
A bash scrpit is easy...
#!/bin/bash

command1
command2
command3

Thank you. I knew it would be simple- but knowing it's simple and knowing what to do are two different things.

And from now on I'll know to use parantheses too. Sweet.

Last edited by pogeymanz (2008-09-26 00:05:36)

Profjim · 2008-09-26 02:10:24

Don't do:

nohup $(commands...)

unless the commands are going to print as a result something that can be executed. For instance, this won't work:

nohup $(echo 10)

because it will turn into:

nohup 10

and you'll get an error message to the effect "command 10 not found". This would work:

nohup $(echo "echo 10")

but I don't know whether the nohup will kick in before the $(...) part has returned. For all I know, it could be that this:

nohup $(long-running-command)

will only have nohup-protection _after_ long-running-command has finished. You may have better luck with one of these constructions:

nohup ( command1; command2; command3 ) # or you could put '&&' between the commands, it won't matter
nohup { command1; command2; command3; }

I don't know whether they will work though, I haven't played around with this. Conceivably you might have to escape the '{'s or '('s. Or do this:

nohup bash -c "command1; command2; command3"

Well, there's no answer here but perhaps it'll help you find one, or prompt someone else who does know the answer...

Daenyth · 2008-09-28 03:57:48

pogeymanz wrote:

Don't I have to have screen installed on the work computer to do what I'm doing? I don't have root privileges, so I can't install stuff.

If you have access to a compiler, compile your own and throw it in $HOME. I also cannot imagine any serious server NOT having screen...

Arch Linux

#1 2008-09-25 21:05:06

Very simple bash question.

#2 2008-09-25 21:33:14

Re: Very simple bash question.

#3 2008-09-25 22:41:55

Re: Very simple bash question.

#4 2008-09-25 22:50:32

Re: Very simple bash question.

#5 2008-09-26 00:04:56

Re: Very simple bash question.

#6 2008-09-26 02:10:24

Re: Very simple bash question.

#7 2008-09-28 03:57:48

Re: Very simple bash question.

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