cat /var/run/yum.pid
<pid>
kill -9 <pid>To get more details, use
ps -p <pid>or
ps -ef | grep <pid>Category: Linux
Delete files owned by a specific user on Linux
Delete all txt files:
find ~/testFolder/*.txt -user @USERNAME -exec rm {} \;Note, the semicolon is necessary.
Delte all files and directories:
find ~/testFolder/ -user @USERNAME -exec rm -rf {} \;But be careful using “-rf”.
“nonexistent” directory in Debian system
As Debian system says,
The canonical non-existent home directory is
/nonexistent. Users who should not have a home directory should have their home directory set to this value.
The Debian autobuilders set HOME to/nonexistentso that packages which try to write to a home directory will fail to build.
2>/dev/null and 2>&1
Remove those entries that have an error of “Permission Denied” :
find /opt -name dcm 2>/dev/nullFilter the output of a program and redirect the filtered result into a file:
./bin/programA -i ... -o ... 2>&1 | grep "keywords" > a.txtUse xmgrace to plot a curve skipping the first row
Sometimes the file that is read by xmgrace has a header like below:
Ratio
0.67
0.52
...If use xmgrace directly, we cannot plot the curve as expected.
I haven’t found the way of using xmgrace only. Instead, I only found how to specify columns using xmgrace.
With the help of other tools, here is a way to work around.
tail -n +2 a.txt | xmgrace -pipeor
sed 1d a.txt | xmgrace -pipeCheck and enable firewalld in Linux
Firewalld is a firewall management solution provided by Linux.
Check if firewalld is running:
sudo firewall-cmd --state
runningDisable firewalld:
sudo systemctl disable --now firewalldCheck its state again:
sudo firewall-cmd --state
not runningEnable firewalld:
sudo systemctl disable --now firewalld
or
sudo /usr/sbin/firewalld