With totem playing a video, running top -p $(pidof totem) -n1 from the terminal works perfectly. Extending it slightly to top -p $(pidof totem) -n1 > ~/test.txt and running it as a once-per-minute cronjob, test.txt is written to, but produces a blank document. There are no errors being produced, or at least nothing is listed in the log files, and Cron doesn't send any mail alerts indicating a problem either. I have no problem getting Cron to run other scripts.
The same thing occurs with all 3 Linux distros I have - Mint 17.2, Deepin 2014, and Ubuntu 10.04.
I have found posts from several people who have encountered the same problem, but unfortunately none of the below suggestions they received work for me;
adding the following;
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
export DISPLAY=:0.0
or any of the following;
export TERM=xterm
top -bn1 | head
TERM=dumb top -n1 | head
TERM=xterm top -n1 | head
At this stage, I'm beginning to think that it's top itself that's buggy. After spending many hours working on a Bash script that's based around top -p, it's pretty demoralising to discover that once done, I now can't get it to run as a cronjob.
Can anyone offer any suggestions as to what the problem might be?
Edit: I'm a mite embarrassed to admit that top -p PID -bn1 | head does work after all! I must have mistyped or something when I tried it first time around! Nevermind, hope it's of help to someone in the future.
Related
I'm puzzled by this problem I'm having on Ubuntu 20.04 where cron is able to run a bash script but the overall outcome is different then when using the shell command.
I've look through all questions I could in here and on Google but couldn't find anyone that had the same problem.
Background:
I'm using Pushgateway to store metrics I'm generating through a bash script, and afterwards it's being imported automatically to Prometheus.
The end goal is to export a list of running processes, their CPU%, Mem% etc, similar to top command.
This is the bash script:
#!/bin/bash
z=$(top -n 1 -bi)
while read -r z
do
var=$var$(awk 'FNR>7{print "cpu_usage{process=\""$12"\", pid=\""$1"\"}", $9z} FNR>7{print "memory_usage{process=\""$12"\", pid=\""$1"\"}", $10z}')
done <<< "$z"
curl -X POST -H "Content-Type: text/plain" --data "$var
" http://localhost:9091/metrics/job/top/instance/machine
I used to have a version that used ps aux but then I found out that it only shows the average CPU% per process.
As you can see, the command I'm running is top -n 1 -bi which gives me a snapshot of active processes and their metrcis.
I'm using awk to format the data, and FNR>7 because I need to ignore the first 7 lines which is the summery presented by top.
The bash scrip is registered on /bin, /usr/bin and /usr/local/bin.
When checking http://localhost:9091/metrics, which is supposed to show me the information gathered, I'm getting this some of information when running the scrip using shell:
cpu_usage{instance="machine",job="top",pid="114468",process="php-fpm74"} 17.6
cpu_usage{instance="machine",job="top",pid="114483",process="php-fpm74"} 11.8
cpu_usage{instance="machine",job="top",pid="126305",process="ffmpeg"} 64.7
And this is the same information when cron is running the same script:
cpu_usage{instance="machine",job="top",pid="114483",process="php-fpm+"} 5
cpu_usage{instance="machine",job="top",pid="126305",process="ffmpeg"} 60
cpu_usage{instance="machine",job="top",pid="128777",process="php"} 15
So, for some reason, when I run it from cron it cuts the process name after 7 places.
I initially though it was related to the FNR>7 but even after changing it to 8 or 9 (and using exec bash to re-register the command) it gives the same results, also when I run it manually it works just fine.
Any help would be appreciated!!
I've googled this question, but never found anything useful for my particular case.
So, what I'm trying to figure out is the PID of a certain command that is running so I can kill it if necessary. I know it's possible to get the PID of a command by typing echo $! So supposedly
my_command & echo $!
should give me the PID. But this isn't the case, and I think I know why:
My command is as follows:
screen -d -m -S Radio /path/to/folder -f frequency -r path/to/song
which opens a detached screen first and then types the command so that it gets executed and keeps on running in the background. This way the PID that echo shows me is the wrong one. I'm guessing it shows me PID of screen -d -m -S Radio /path/to/folder -f frequency -r path/to/song instead of the PID of the command run in the new terminal created by screen.
But there's another problem to it: when I run screen -ls in the terminal, the command that is running in the background doesn't show up! I'm fairly certain it's running because the Pi is constantly at 25% CPU usage (instead of the 0% or 1% usually) and when I type ps au I can actually see the command and the PID.
So now I'm calling the community: any idea on how I could find the PID of that certain command in the new terminal? I'm writing a bash script, so it has to be possible to obtain the PID through code. Perfect would be a command that stores the PID in a variable!
Thanks to #glennjackman I managed to get the PID I wanted with a simple pgrep search_word. At first it wasn't working, but somehow I made it work after some trial and error. For those wanting the PID on a variable, just type
pid=$(pgrep search_word)
Regarding the problem with screen -ls not showing my detached session, it's still not solved, but I'm not bothered with it. Thanks again for solving my problem #glennjackman !
EDIT:
Second problem solved, check the comments on berends answer.
You can easily find out all the running process and their PID by writing (for example):
ps aux
The process is run by screen so you can probably find it easier by writing:
ps aux | grep screen
For more info about ps and the parameters I used check (quick google) -> https://www.lifewire.com/g00/uses-of-linux-ps-command-4058715?i10c
EDIT: You can use this command with bash scripting as well.
im trying to use tee command with rendercheck tests on ubuntu 15.04, tee command works fine with 6 tests of rendercheck for example :
./rendercheck -t fill,dcoords,scoords,mcoords,tscoords,tmcoords | tee summary
but if i added other more , example :
./rendercheck -t fill,dcoords,scoords,mcoords,tscoords,tmcoords,composite | tee summary
the output does not shows in terminal and the file summary does not contain nothing, so im not sure why i have this behavior with tee command, it would be great if someone can help me, thanks
"composite" test opens a graphic window, doesn't display text to standard output.
I guess you'll obtain the same behavior if you just execute:
rendercheck composite | tee summary
Regards
I've a number of accounts running cron-started php jobs hourly.
The generic structure of the command is this:
wget -q -O - http://some.site.com/cron.php
Now, this used to be running just fine.
Lately, though, on a number of accounts it has started playing up - but only on this one server. Once or twice a day the php file is not run.
The access log is missing the relevant entry.
While the cron log shows that the job was run.
We've added a bit to the command to log things out (-o /tmp/logfile) but it shows nothing.
I'm at a loss, really. I'm looking for ideas what can be wrong, or how to sidestep this issue as it has started taking up way too much of my time.
Has anyone seen anything remotely like this?
Thanks in advance!
Try this command
wget -d -a /tmp/logfile -O - http://some.site.com/cron.php
With -q you turn off wget's output. With -d you turn on debug output (maybe -v for verbose output is already enough). With -a you append logging messages to /tmp/logfile instead of always creating a new file.
You can also use curl:
curl http://some.site.com/cron.php
Why do I get the Waiting...Fatal error: watch ENOSPC when I run the watch task ?
How do I solve this issue?
After doing some research found the solution. Run the below command.
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
For Arch Linux add this line to /etc/sysctl.d/99-sysctl.conf:
fs.inotify.max_user_watches=524288
Any time you need to run sudo something ... to fix something, you should be pausing to think about what's going on. While the accepted answer here is perfectly valid, it's treating the symptom rather than the problem. Sorta the equivalent of buying bigger saddlebags to solve the problem of: error, cannot load more garbage onto pony. Pony has so much garbage already loaded, that pony is fainting with exhaustion.
An alternative (perhaps comparable to taking excess garbage off of pony and placing in the dump), is to run:
npm dedupe
Then go congratulate yourself for making pony happy.
After trying grenade's answer you may use a temporary fix:
sudo bash -c 'echo 524288 > /proc/sys/fs/inotify/max_user_watches'
This does the same thing as kds's answer, but without persisting the changes. This is useful if the error just occurs after some uptime of your system.
To find out who's making inotify instances, try this command (source):
for foo in /proc/*/fd/*; do readlink -f $foo; done | grep inotify | sort | uniq -c | sort -nr
Mine looked like this:
25 /proc/2857/fd/anon_inode:inotify
9 /proc/2880/fd/anon_inode:inotify
4 /proc/1375/fd/anon_inode:inotify
3 /proc/1851/fd/anon_inode:inotify
2 /proc/2611/fd/anon_inode:inotify
2 /proc/2414/fd/anon_inode:inotify
1 /proc/2992/fd/anon_inode:inotify
Using ps -p 2857, I was able to identify process 2857 as sublime_text. Only after closing all sublime windows was I able to run my node script.
I ran into this error after my client PC crashed, the jest --watch command I was running on the server persisted, and I tried to run jest --watch again.
The addition to /etc/sysctl.conf described in the answers above worked around this issue, but it was also important to find my old process via ps aux | grep node and kill it.
In my case it was related to vs-code running on my Linux machine. I ignored a warning which popped up about file watcher bla bla. The solution is on the vs-code docs page for linux https://code.visualstudio.com/docs/setup/linux#_visual-studio-code-is-unable-to-watch-for-file-changes-in-this-large-workspace-error-enospc
The solution is almost same (if not same) as the accepted answers, just has more explanation for anyone who gets here after running into the issues from vs-code.
In my case I found that I have an aggressive plugin for Vim, just restarted it.