Re: a command "spool", ie queueing commands?

[urgrue <urgrue@xxxxxxxxx>]

> Could you please give us a real-life example?

Well, for example imagine you're doing some maintenance on a server.  
You want to move some big files, run updatedb by hand, run a script  
that parses a bunch of files, and finally merge some video files.

Because these are very disk-heavy operations, it's much better and  
quicker if they are not run at once, but are run sequentially instead.

So normally you'd probably use "at" to run one now, another in an hour,  
etc. But this is dumb because you have to simply try and guess if the  
job is done or not. You could also run them in sequence by putting them  
all in the same "at" job, but its not possible to add or remove  
commands from an "at" job once its created. Also, "at" is "user-aware",  
ie if two users set up two at jobs they will happily run at the same  
time. What I propose would add all commands to the same queue, even if  
a different user is the one launching the command (but of course the  
commands should be run AS the user who started it).

So what I'm thinking is like this (lets assume the command is called  
"cs" for "command spooler"):
me:~> cs
Usage: cs [add|remove|show] <command>
me:~> cs show
no entires
me:~> cs add mv /path/hugefiles /other/path/hugefiles
command added to queue
me:~> cs show
1 [running] : mv /path/hugefiles /other/path/hugefiles
me:~> cs add updatedb
command added to queue
me:~> cs add /path/my_file_parsing_script /path/lots/of/files
command added to queue
me:~> cs add avimerge -i clip1.avi clip2.avi clip3.avi -o allclips.avi
command added to queue
me:~> cs show
1 [running] : mv /path/hugefiles /other/path/hugefiles
2 [queued]  : updatedb
3 [queued]  : path/my_file_parsing_script /path/lots/of/files
4 [queued]  : avimerge -i clip1.avi clip2.avi clip3.avi -o allclips.avi


As I do lots of disk-heavy operations, I would find this INCREDIBLY  
useful.

urgrue


> --Adrian.
>
> On 8/2/05, urgrue <urgrue@xxxxxxxxx> wrote:
> > i realized it would be useful to be able to add commands into a
> command
> > queue, from where they would get executed in sequence. for example
> > numerous large hard disk-intensive operations would be better
> executed
> > in sequence rather than at once.
> > in other words, exactly like a printer spool, but for commands. you
> > could add commands in, list the queue, and remove from the queue.
> >
> > does anyone know of something like this?
> >
> >
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