I use an alert command which notifies me whenever a bash comand runs (e.g. ./long_running_task ; alert) will send an alert whenever long_running_task completes. I sometimes forget to write ; alert at the end of my commands, so I'm wondering if there's a way to automatically trigger this--like with some sort of shim. The answers here seem to only work if I want to run alert before long_running_task, which won't help in my case.
Is there a way to call the alert command after every shell command that I run from the terminal?
Found out you can do this by setting the PROMPT_COMMAND variable. In my bashrc, I added this line: export PROMPT_COMMAND='alert'.
Related
I have seen many ways to launch a script like putting it in profile.D, rc.local, or creating a auto start file but none of those launch the file in a visible window if at all. I need it to be in a visible window in Ubuntu. I need to do this because I am using several emulators to stream to different services, and I don't want to have to start the script on each manually.
I am using visual box for the emulator. The sh file is on a removable drive because it is an external file. I also need it to run as sudo.
Edit: I don't actually need it to run at startup. I just need to have the script run. I can probably just sleep really long for graphic to load.
Edit 2: So I created a service that launched a sh file in /usr/bin/ which was supposed to create a gnome-terminal window that ran my script. It ran, however It didn't create a visible window for some reason. I then tried to specify a display which caused gnome to freak out. Dbus was not launching correctly. another question stated that gnome would not work because of how it was designed and stated to use konsole instead. Konsole also stated that it could not connect to a display, giving a QXcbConnection error. Konsole does not have an option to specify display. I don't know what else to try
Edit 3: So I did the thing in the comment. And the service works. However it only works after I run the file that the service runs in usr/bin manually after every restart. The important parts of the file:
#!/bin/bash
sleep 60
ufw disable
ssh nateguana#$(hostname) -X
xhost +
*launch Gnome**only works after file ran manually*
I have also tried exporting DISPLAY, and changing users with su. I have not tried importing SSHD, as another question said to do, as I think that is only for non local connections. I have also tried every single arrangement of commands possible. Xhost errors stating that it is unable to open display "".
You can use gnome-terminal -e <command> to spawn a new bash terminal which runs the command.
You could use something like
gnome-terminal -e /path/to/bashfile
Bear in mind, this will end the terminal after the bash scipt is done executing.
To avoid this,in a newline add $SHELL to the end of your bash script.
PS: the -e argument is deprecated and might be removed in later versions
I want to prevent a bash command from executing that has been chained using ; from running while the previous command is still running.
e.g. I write and submit command a; command b, but while command a is running I change my mind and want to prevent command b from running.
I cannot use kill because the subsequent command is not actually executing. Does bash have a queue of commands that can be manipulated?
To clarify, I am sure it is possible to make a new script or something that would allow me to create a queue, but that is not what this question is about. I specifically want to know if bash can prevent commands after a semicolon from running after I've 'submitted' them.
Consider these two scripts:
runner.sh
#!/bin/bash
while true
do
next_command=$(head -1 next_commands.list)
$next_command
sleep 60 #added to simulate processing time
done
next_commands.list
id
ls
echo hello
You can modify the content of the next_commands.list file to create a type of queue of which commands should be executed next.
I would like to configure my bash in a way so that I react on the event that the user enters a command. The moment they press Enter I would like my bash to run a script I installed first (analog to any PROMPT_COMMAND which is run each time a prompt is given out). This script should be able to
see what was entered,
maybe change it,
maybe even make the shell ignore it (i. e. make it not execute the line),
decide on whether the text shall be inserted in the history or not,
and maybe similar things.
I have not found a proper way to do this. My current implementations are all flawed and use things like debug traps to intervene before executing a command or (HISTTIMEFORMAT='%s '; history 1) to ask the history after the command execution is complete about things when the command was started etc (but that is only hindsight which is not really what I want).
I'd expect something like a COMMAND_INTERCEPTION variable which would work similar to PROMPT_COMMAND but I'm not able to find anything like it.
I also considered to use command line completion to achieve my goal but wasn't able to find anything about reacting on sending a finished command in this, but maybe I just didn't find it.
Any help appreciated :)
You can use the DEBUG trap and the extdebug feature, and peek into BASH_COMMAND from the trap handler to see the running command. (Though as noted in comments, the debug trap is sprung on every simple command, not every command line. Also subshells elude it.)
The debug handler can prevent the command from running, but can't change it directly. Though of course you could run any command inside the debugger, possibly using BASH_COMMAND and eval to build it and then tell the shell to ignore the original command.
This would prevent running anything starting with ls:
$ preventls() { case "$BASH_COMMAND" in ls*) echo "no!"; return 1 ;; esac; }
$ shopt -s extdebug
$ trap preventls DEBUG
$ ls -l
no!
Use trap - DEBUG to remove the trap. Tested on Bash 4.3.30.
Hi I'm trying to run a script that calls xclip in order to have a string ready to paste when i connect to the internet.
I have a script /etc/network/if-up.d/script that does execute when connecting (i make him post a date in a file succesfuly ) but the xclip instruction seems not to work, there's nothing to paste. If i call this script manually by typing /etc/network/if-up.d/script in a console it works perfectly.
If i try to launch a zenity message it also don't appeare when connecting. Again if i do it by hand it appeares.
Then I have a expect script that calls matlab (console mode), if I execute it manually it works but if i call it from cron it freezees when calling the script.
It's driving me crasy since it seems that only certain commands in a script can be executed when the system calls them automaticaly.
I'v tryed to call the instructions with nohup instruction & but still misses
This is working as designed, you search around and will see compliated ways to resolve this issue, or you can use xmessage as I describe here: Using Zenity in a root incron job to display message to currently logged in user
Easy option 1: xmessage (in the script)
MSSG="/tmp/mssg-file-${RANDOM}"
echo -e " MESSAGE \n ==========\n Done with task, YEY. " > ${MSSG}
xmessage -center -file ${MSSG} -display :0.0
[[ -s ${MSSG} ]] && rm -f ${MSSG}
Easy option 2: set the DISPLAY (then should work)
export DISPLAY=:0 && /usr/bin/somedirectory/somecommand
question is answered here for cron :
http://ubuntuforums.org/archive/index.php/t-105250.html
and here for if-up network :
Bash script not working properly when run automatically
I wrote an init script to execute last that will start some pythjon script. The Python script will just run and never terminate and this makes my little linux box (getty terminal on tty) to just outpout the script but never the login prompt. I made the mistake to not assign a fix ip so i basically had to start over again (re-download the initial build onto the flash). However now I'm wondering what different possibilities I have, is it enough to launch the script in my init script with a & at the end or do I need a nohup/ What's the best way to resolve this?
Thank you!
Ron
I got this resolved by directing the output of the script to /dev/null and adding an ampersand at the end kinda like
myscript.sh > /dev/null &
this will return control to the shell and keep executing the script in the back without reporting the results to stdout.
Yes, you need to make sure you init startup script returns. It's good to follow the LSB documentation and have a script that excepts standard actions like start, stop, status and make it return proper return codes.
Launching the python script in the background with an & at the end of the command should be sufficient. You may also want to take a look at the command start-stop-daemon to start your process.