I am working on a Raspberry Pi powered Magic Mirror project and to start the program I execute a shell script that runs in the background continuously. To make the AI part of my project work I need to open a second shell script in the background that also runs continuously. My problem occurs when I try to execute my Xterm commands it waits for the first script to complete before it starts the second script. Since both scripts have no designated end point I am stuck. Is there a way to make both Xterm commands execute at the same time?
Here is my current code to start the Xterm sessions:
cd ~/MMStartAll
xterm -e "cd ~/MMStartAll; ./AssistantStart.sh"
xterm -e "cd ~/MMStartAll; ./MMStart.sh"
$SHELL
Your script should end with a &. This means that both the xterms will run in a sepperate process id (pid).
cd ~/MMStartAll
xterm -e "cd ~/MMStartAll; ./AssistantStart.sh" &
xterm -e "cd ~/MMStartAll; ./MMStart.sh" &
$SHELL
Related
I need to start a couple of processes locally in multiple command-prompt windows, to make it simple, I have written a shell script say abc.sh to run in git-bash which has below commands:
cd "<target_dir1>"
<my_command1> &>> output.log &
cd "<target_dir2>"
<my_command2> &>> output.log &
when I run these commands in git bash I get jobs running in the background, which can be seen using jobs and kill command, however when I run them through abc.sh, I get my processes running in the background, but the git-bash instance disowns them, now I can no longer see them using jobs.
how can I get them run through the abc.sh file and also able to see them in jobs list?
I want to write a bash script that runs two commands in the background. I am using nohup for this:
nohup cmd1 &
nohup cmd2 &
However, only the 1st command runs in the background.
When I run nohup cmd1 & manually in the command line. First, I type nohup cmd1 & then hit enter; this starts the process:
But, then I need to hit enter again to be able to type another command:
I think this is "clogging" up the command line, and is causing my bash script to get stuck at the first nohup ... & command.
Is there a way to prevent this?
Nothing is "clogged". The first command, running in the background, prints some output after your shell prints its next prompt. The shell is waiting for you to type a command, even though the cursor is no longer on the same line as the prompt. That extra Enter is an empty command, causing the shell to print another prompt. It's harmless but unnecessary.
Let me say something to nohup because I'm not sure if you are certain about what it is doing. In short, the nohup command is not necessary to run a process in background. The ampersand at the end of the line is doing it.
nohup prevents the background process from receiving SIGHUP (hup for hang up) if you close the terminal where the starting shell runs it. SIGHUP would effectively terminate the process.
If started with nohup the process will not receive that event and will continue running, owned by the init process (pid 1) if the terminal will being closed.
Furthermore the nohup command will redirect standard output of the controlled process to a file, meaning it will not appear on screen any more. By default this file is called nohup.out.
I need to launch a script that will act like a daemon from another script and will not prevent me from being able to close Terminal window.
I tried these standard solutions inside my script :
./myscript.sh arg1 arg2 &
Or this
nohup ./myscript.sh arg1 arg2 &
but they all prevent me from being able to close Terminal window
I don't need any output from that subsidiary script.
Do you know a way to do that in standard UNIX shell, or if I can find some builtin commands or services on Mac to ask to run that script on my behalf.
Thanks
This might work:
xterm -e 'sh /path/to/script.sh' &
You may also want to include the -hold option as well.
I have a bash script with a lot of lines using the command gnome-terminal so it can open several terminals an execute programs. The problem is that some of the programs depend of the executing of one in particular that takes some time, so I need to be sure that this line stop running before the bash can continue with the next.
One way to do it is to put a wait time with "sleep", calculating how much time this program needs to run for completed; but someone know a more efficient way?
Thank you.
Instead of
xterm -e program1 &
xterm -e program2 &
use
program1
program2
or if you absolutely need them to run in an xterm,
xterm -e sh -c 'program1; program2'
The more sane solution is to factor out the xterms from the actual script and do
xterm -e path/to/yourscript &
when you want your script to run in an xterm.
my bash script reads in a few variables and then runs airodump on my home network. I would like to keep the window with airodump running and open some new terminals to run other commands for network discovery while the airodump screen is open (so i can see the results).
right now what i have looks like this (edited for brevity):
#!/bin/bash
read -p "Enter the channel: $channel"
airomon-ng start wlan0 $channel,$channel
airodump-ng -c $channel,$channel mon0 &&
terminator -e netstat -ax &&
terminator -e nmap 192.168.1.1
the first command that uses the whole terminal (airodump) starts up fine and i can see the network, but then it just stays on that screen. If i ctrl+c then it goes back to prompt but i can see the error : Usage: terminator [options] error no such option
i want the netstat and nmap commands to appear and stay in their own terminal windows, how can i do this?
The terminal window is generated by a separate program from the command running inside. Try one of these variations:
xterm -e airomon-start wlan0 "$channel","$channel" &
gnome-terminal -x airomon-start wlan0 "$channel","$channel" &
konsole -e airomon-start wlan0 "$channel","$channel" &
Pick the command that invokes the terminal program you like. You'll have to do this for every command that you want run in its own window. Also, you need to use a single & at the end of each such command line -- not a double && -- those do totally different things. And the last line of your script should be just
wait
that makes it not exit out from under all the terminals, possibly causing them all to die.
Obligatory tangential shell-scripting nitpick: ALWAYS put shell variable uses inside double quotes, unless you know for a fact that you need word-splitting to happen on a particular use.
If the script is running in the foreground in the terminal, then it will pause while an interactive command is using the terminal. You could change the script to run airodump in a new terminal as well, or you could run the background commands before you start airodump (maybe after sleeping, if you're concerned they won't work right if run first?)