I have some trouble using "recordmydesktop" (capturing video of the computer screen) in command line.
I have a shell script that find the ID of a specific window and launch recordmydesktop with the window ID.
Here is my script :
recordmydesktop --no-sound --delay 3 --windowid $(xwininfo -name "NAME" | sed -n 's/.*Window id: \([0-9a-fx]\+\).*/\1/p')
NAME is the name of the window to record.
The thing is, I want to record during X seconds, and in the man help, there is no options to do that.
The app can be stopped with "Ctrl+C", but I want to make it automatically after X seconds.
Any idea ?
Thanks for reading me :)
#!/bin/bash
recordmydesktop --no-sound --delay 3 --windowid $(xwininfo -name "NAME" | sed -n 's/.*Window id: \([0-9a-fx]\+\).*/\1/p') &
sleep $1; pkill recordmydesktop
or if you need Ctrl+c:
sleep $1; pkill --signal=SIGINT recordmydesktop
value of pause - first scripts parameter
Related
I'm using almost the default bspwmrcand sxhkdrc.
I'm working on a laptop and as far as I'm not connecting it to my monitor everything works just fine.
xrandr --output HDMI1 --mode 1920x1080 now breaks it. If I want to go to workspace one with Super+1 then nothing happens. Instead workspace one windows are now reachable on workspace two.
Thanks in advance!
You have to decide on xrandr output how many monitors are attached while you start BSPWM.
BSPWM is tiling window manager and it does its job very good.
start_from=1
monitors_connected=$(bspc query -M | wc -l)
per_monitor=$(( 10 / monitors_connected ))
for monitor in $(bspc query -M); do
bspc monitor $monitor -d $(seq $start_from $(( start_from + per_monitor - 1)))
start_from=$(( start_from + per_monitor ))
done
In your case, it will put first 5 workspaces on the first monitor and other 5 on external monitor.
The code above you can include inside your bspwmrc before you start some status bar program.
while pgrep -x polybar >/dev/null; do sleep 1; done
xrandr -q | awk '/ connected / {print $1}' | while read -r monitor _; do
polybar -r "$monitor" &
done
so polybar for every connected monitor will run. If there is only one monitor, nothing will happen.
How can I write a bash script to print out the PIDs of all processes in the foreground process group of a given terminal (which is different from the one in which I run the script)? I know that the C function tcgetpgrp can do the job, but I am wondering if there exist any command line utilities that can do this more easily.
To find the pids of all processes in the foreground process group of pts/29, you can do (on linux):
ps ao stat=,pid=,tty= | awk '$1 ~ /\+/ && $3 ~ /pts\/29/{ print $2}'
ps is often different, and I am uncertain of the portability of that solution.
You can use pgrep's -t flag, which enables you to list process using a given tty.
For example :
# on a first ssh session, which gets pts/0 :
sleep 10
# on a second ssh session :
pgrep -t "pts/0"
1234 # the first session's bash process
5678 # the first session's sleep process
I need something like $command & stop This should execute a command and suspend it. The application later resumes back the command for complete results.
I understand that job can be suspended with stop signal to the corresponding pid.
$kill -SIGSTOP 12753
When we execute a command, we barely know its pid. There is extra command involved to take a pid and do the required. I want to avoid the extra command and a time interval.
Basically The application is for a measure of network performance. Trigger all the commands put them in halt mode. The halted commands are resumed back as per the kind of traffic needed.
The process ID of the most recently started background command is available in the shell parameter $!:
$ command & kill -SIGSTOP $!
(Check the documentation for your shell's implementation of kill for the correct format.)
Try killall with the --signal option where you can specify the name of the process.
linux:~ # killall
Usage: killall [OPTION]... [--] NAME...
killall -l, --list
killall -V, --version
-e,--exact require exact match for very long names
-I,--ignore-case case insensitive process name match
-g,--process-group kill process group instead of process
-i,--interactive ask for confirmation before killing
-l,--list list all known signal names
-q,--quiet don't print complaints
-r,--regexp interpret NAME as an extended regular expression
-s,--signal SIGNAL send this signal instead of SIGTERM
-u,--user USER kill only process(es) running as USER
-v,--verbose report if the signal was successfully sent
-V,--version display version information
-w,--wait wait for processes to die
Verified by starting md5sum in a shell session:
linux$ md5sum
and in another session, ran:
killall -s SIGSTOP md5sum
yielding the following in the md5sum session:
[1]+ Stopped md5sum
Kindly confirm if you want to halt your command or run in background(append '&' to your command)?
If your application is expected to start halted command later, then why dont you start your command(to be halted) in that application itself.
This helps :
sleep 5 & kill -SIGSTOP $!
In above, have executed sleep(demo command) for 5 seconds in background.
Next have send to kill for stopping it using its PID obtained by $!.
Demo & kludge using timeout, (for some reason timeout intereprets a '0s' duration as "run forever"), to stop yes before it outputs anything:
# run 'yes' command, let it print 5 numbered lines, but stop it immediately
timeout -s SIGSTOP .000000001s yes | head -n 5 | cat -n
Output (to STDERR):
[1]+ Stopped timeout -s SIGSTOP .000000001s yes | head -n 5 | cat -n
Now restart it:
fg > /dev/null
Output:
1 y
2 y
3 y
4 y
5 y
Technique for users stuck with v8.12 or earlier coreutils, (pre-2011), wherein timeout lacks sub-second intervals. Requires waiting a second.
Wrap the command string in a shell invocation, preceded by a 1s wait -- so timeout waits 1 second, and simultaneously, so does the command string. Total wait time 1 second:
timeout -s SIGSTOP 1s sh -c "sleep 1s; yes | head -n 5 | cat -n"
Output is the same as before, fg is the same too.
Finesse, if waiting even 1 second before sleeping is too much, it can be run in the background like so:
timeout -s SIGSTOP 1s sh -c "sleep 1s; yes | head -n 5 | cat -n" &
Output (process number will vary):
[1] 14601
Then after a second, the output will be the same as the previous two timeout examples.
Assuming you are using the same command, find the command name in ps output, you can launch it in one terminal then open a new terminal
ps -ely
after retrieving the command name:
command & kill -SIGSTOP $(pidof command_name)
pidof needs the exact command name to be able to find the pid.
then to resume it:
kill -SIGCONT $(pidof command_name)
if the command name is not constant, but there is a pattern, you can create a script like this, you can call it pof.sh:
ps -ely | grep $1 | tr -s ' ' | cut -d" " -f3
command & kill -SIGSTOP $(bash pof.sh pattern)
One drawback with this script, is that in case many lines match the pattern it will returns all of theirs pids, if this is a problem, you can put the output in an array and go on from there.
I have this script:
#!/bin/sh
while [ true ] ; do
urlfile=$( ls /root/wget/wget-download-link.txt | head -n 1 )
dir=$( cat /root/wget/wget-dir.txt )
if [ "$urlfile" = "" ] ; then
sleep 30
continue
fi
url=$( head -n 1 $urlfile )
if [ "$url" = "" ] ; then
mv $urlfile $urlfile.invalid
continue
fi
mv $urlfile $urlfile.busy
wget -b $url -P $dir -o /www/wget.log -c -t 100 -nc
mv $urlfile.busy $urlfile.done
done
The script basically checks for any new URLs at wget-download-link.txt for every 30 seconds and if there's a new URL it'll download it with wget, the problem is that when I try to run this script on Putty like this
/root/wget/wget_download.sh --daemon
it's still running in the foreground, I still can see the terminal output. How do I make it run in the background ?
In OpenWRT there is neither nohup nor screen available by default, so a solution with only builtin commands would be to start a subshell with brackets and put that one in the background with &:
(/root/wget/wget_download.sh >/dev/null 2>&1 )&
you can test this structure easily on your desktop for example with
(notify-send one && sleep 15 && notify-send two)&
... and then close your console before those 15 seconds are over, you will see the commands in the brackets continue execution after closing the console.
The following command will also work:
((/root/wget/wget_download.sh)&)&
This way you don't have to install the 'nohub' command in the tight memory space of the router used for OpenWrt.
I found this somewhere several years ago. It works.
The &at the end of script should be enough, if you see output from the script it means, that stdout and/or stderr is not closed, or not redirect to /dev/null
You can use this answer:
How to redirect all output to /dev/null
I am using openwrt merlin and the only way to get it working was using the crud cron manager[1]. Nohub and screen are not available as solutions.
cru a pinggw "0 * * * * /bin/ping -c 10 -q 192.168.2.254"
works like charm
[1][https://www.cyberciti.biz/faq/how-to-add-cron-job-on-asuswrt-merlin-wifi-router/]
https://openwrt.org/packages/pkgdata/coreutils-nohup
opkg update
opkg install coreutils-nohup
nohup yourscript.sh &
You can use nohup.
nohup yourscript.sh
or
nohup yourscript.sh &
Your script will keep running even if you close your putty session, and all the output will be written to a text file in same directory.
nohup is often used in combination with the nice command to run processes on a lower priority.
nohup nice yourscript.sh &
See: http://en.wikipedia.org/wiki/Nohup
For busybox in Openwrt Merlin system, I got a better solution which combined cru and date command
cru a YOUR_UNIQUE_CRON_NAME "`date -D '%s' +'%M %H %d %m *' -d $(( \`date +%s\`+2*60 ))` YOUR_CMD_HERE"
which add a cron job running 2 minutes later, and only run once.
Inspired by PlagTag's idea.
In another way these code would tried:
ssh admin#192.168.1.1 "/jffs/your_script.sh &"
Simple and without any programs like nohup screen...
(BTW: worked on Asus-Merlin firmware)
Try this:
nohup /root/wget/wget_download.sh >/dev/null 2>&1 &
It will go to the background so when you close your Putty session, it will be still running, and it won't send messages to the terminal.
I want to run a cron job every minute that will launch a script. Simple enough there. However, I need to make sure that not more than X number (defined in the script) of instances are ever running. These are queue workers, so if at any minute interval 6 workers are still active, then I would not launch another instance. The script simply launches a PHP script which exits if no job available. Right now I have a shell script that perpetually launches itself every 10 seconds after exit... but there are long periods of time where there are no jobs, and a minute delay is fine. Eventually I would like to have two cron jobs for peak and off-peak, with different intervals.
Make sure you have unique script name.
Then check if 6 instances are already running
if [ $(pgrep '^UNIQUE_SCIPT_NAME$' -c) -lt 6 ]
then
# start my script
else
# do not start my script
fi
I'd say that if you want to iterate as often as every minute, then a process like your current shell script that relaunches itself is what you actually want to do. Just increase the delay from 10 seconds to a minute.
That way, you can also more easily control your delay for peak and off-peak, as you wanted. It would be rather elegant to simply use a shorter delay if the script found something to do the last time it was launched, or a longer delay if it did not find anything.
You could use a script like OneAtATime to guard against multiple simultaneous executions.
This is what i am using in my shell scripts:
echo -n "Checking if job is already running... "
me=`basename $0`
running=$(ps aux | grep ${me} | grep -v .log | grep -v grep | wc -l)
if [ $running -gt 1 ];
then
echo "already running, stopping job"
exit 1
else
echo "OK."
fi;
The command you're looking for is in line 3. Just replace $(me) with your php script name. In case you're wondering about the grep .log part: I'm piping the output into a log file, whose name partially contains the script name, so this way i'm avoiding it to be double-counted.