I'm unable to get the at command to run from the Mac Terminal.
I've tried at -f test.txt 10:44 which puts it in the queue, but then it never runs.
I've tried sh test.txt | at 10:43 which puts it in the queue (though it never runs), but it also runs the script immediately.
Just running sh test.txt runs fine, it is a test script to send an email.
What am I doing wrong?
I think the answer may be in the man page. man at, IMPLEMENTATION
NOTES Note that at is implemented through the launchd(8) daemon
periodically invoking atrun(8), which is disabled by default. See
atrun(8) for information about enabling atrun.
This is from the comment by Justin Wood.
I thank him for his help - I should have read the man page more closely.
Related
I received an application code that can be run on Linux kernel 4.4.60 as below cmd - per their app note :-
/usr/sbin/server_application | logger -t tag &
If I run the server_application with just "server_application &" (in the background), then the socket which the process attempts to create fails the initiation. And obviously the client_application (run separately of course) times out.
From my info, the linux logger utilities only make entries in the system log.
Q. -- What is it the application might need which requires the application to log the tag entries in the syslog?
I am trying to reverse engineer as to why it needs logger specifically.
Any thoughts on this would be greatly appreciated.
Thanks in advance.
If you run the server_application in background the process might not have standard output at all opened to anything and any writes to stdout will fail. If you create a pipeline piping the standard output to a program then the server_application will have different characteristics for its stdout.
You could also try to figure out the difference by running these two with strace, for example:
strace -o /tmp/syscall.log /usr/sbin/server_application &
strace -o /tmp/syscall.log /usr/sbin/server_application | logger -t tag &
and by reading the /tmp/syscall.log looking for failed system calls near the end of the run for the former and then comparing them with the calls from the latter.
After copying myexentension#me.com folder to .../gnome-shell/extensions/ I'm executing this command on the terminal:
gnome-shell-extension-tool -e myexentension#me.com
Then, I restart my session with Alt + F2 and execute r, and everything works fine.
But can I start my extension only through the command line? Without Alt+F2+r? Without restarting my gnome-shell session?
According to some answers around the internet, sending SIGHUP to the gnome-shell process restarts it (i. e. killall -HUP gnome-shell), but I haven’t been able to find a clear source on this and couldn’t find the signal handling in the code. What I do know is that this should be exactly equivalent to Alt+F2 r:
busctl --user call org.gnome.Shell /org/gnome/Shell org.gnome.Shell Eval s 'Meta.restart("Restarting…")'
Because apart from a gettext call on the message, this is exactly what Alt+F2 r is bound to (see runDialog.js – search for _restart).
January 2022 update: Since Gnome 41, calling Eval is restricted and requires “unsafe mode” to be enabled, so by default this will no longer work. I’m not currently aware of a replacement for this particular usage.
Personally, I prefer a solid Alt+F2, r+Enter but maybe try disabling and enabling:
gnome-shell-extension-tool -d myexentension#me.com && gnome-shell-extension-tool -e myexentension#me.com
or
gnome-shell-extension-tool -r myexentension#me.com
Which may do the same thing. There's also gnome-shell-extension-prefs which you can use to do the same thing (and is typically hidden in Gnome for some reason).
I have a VM that I want running indefinitely. The server is always running but I want the script to keep running after I log out. How would I go about doing so? Creating a cron job?
In general the following steps are sufficient to convince most Unix shells that the process you're launching should not depend on the continued existence of the shell:
run the command under nohup
run the command in the background
redirect all file descriptors that normally point to the terminal to other locations
So, if you want to run command-name, you should do it like so:
nohup command-name >/dev/null 2>/dev/null </dev/null &
This tells the process that will execute command-name to send all stdout and stderr to nowhere (instead of to your terminal) and also to read stdin from nowhere (instead of from your terminal). Of course if you actually have locations to write to/read from, you can certainly use those instead -- anything except the terminal is fine:
nohup command-name >outputFile 2>errorFile <inputFile &
See also the answer in Petur's comment, which discusses this issue a fair bit.
Well, what I need to do actually is CTRL-Z out of a process that got started from insert mode in GVim.
My command :Cdprun executes cdprun.sh which runs a sudo-ed daemon. I can add & at the end of the sudo-ed daemon call to run in the background and that works but the user doesn't get prompted for a password. Instead I want to just CTRL-Z out of it but the keyboard interrupt doesn't work. Any ideas? Thx.
You generally have two options in this case: generic is using something like vim-addon-async mentioned by #Nicalas Martin or vim with built-in interpreters support: tcl with expect module, python with pyexpect, perl with Expect, maybe something else (note: all of the mentioned packages are not shipped with tcl/python/perl). Second is specific to current situation: it is backgrounding in the other place. From your explanation I guessed that you have a script looking like
#!/bin/sh
<...>
sudo run-daemon --daemon-args # Last executed line
, am I right? Than you can just put backgrounding in another place: not
sudo run-daemon --daemon-args &
, but
sudo sh -c "nohup run-daemon --daemon-args &"
Here is a script to deal with asynchronous command in vim. Not a perfect solution but could be a good temporary solution. http://www.vim.org/scripts/script.php?script_id=3307
I'm running a Bukkit (Minecraft) server on a Linux machine and I want to have the server gracefully shut down using the server's stop command and the computer suspend at a certain time using pm-suspend from the command line. Here's what I've got:
me#comp~/dir$ perl -e 'sleep [time]; print "stop\\n";' | ./server && sudo pm-suspend
(I've edited by /etc/sudoers so I don't have to enter my password when I suspend.)
The thing is, while the perl -e is sleeping, the server is expecting a constant stream of bytes, (That's my guess. I could be misunderstanding something.) so it prints out all of the nothings it receives, taking up precious resources:
me#comp~/dir$ ...
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>...
Is there any such thing as a buffered pipe? If not, are there any ways to send delayed input to a script?
You may want to have a look at Bukkit's wiki, which recommends an init script for permanently running servers.
This init script uses rather unconventional approach to communicate with running server. The server is started in screen session, then all commands are send to the server console via screen, e.g.
screen -p 0 -S $SCREEN -X eval 'stuff \"stop\"\015'
See https://github.com/Ahtenus/minecraft-init/blob/master/minecraft
This approach suggest that bukkit may be expecting standard input to be attached to a terminal, thus requiring screen wrapper (which is itself terminal emulator) for unattended runs.