1-保存man-page 为pdf文件
man -t awk | ps2pdf - awk.pdf
2-Duplicate installed packages from one machine to the other (RPM-based systems)
ssh root@remote.host "rpm -qa" | xargs yum -y install
3-Stamp a text line on top of the pdf pages to quickly add some remark, comment, stamp text, … on top of (each of) the pages of the input pdf file
echo "This text gets stamped on the top of the pdf pages." | enscript -B -f Courier-Bold16 -o- | ps2pdf - | pdftk input.pdf stamp - output output.pdf
4-Display the number of connections to a MySQL Database
mysql -u root -p -BNe "select host,count(host) from processlist group by host;" information_schema
5-Create a local compressed tarball from remote host directory
ssh user@host "tar -zcf - /path/to/dir" > dir.tar.gz
6-tail a log over ssh
ssh -t remotebox "tail -f /var/log/remote.log"
7-Print diagram of user/groups
awk 'BEGIN{FS=":"; print "digraph{"}{split($4, a, ","); for (i in a) printf "\"%s\" [shape=box]\n\"%s\" -> \"%s\"\n", $1, a[i], $1}END{print "}"}' /etc/group|display
8-Draw kernel module dependancy graph.
lsmod | perl -e 'print "digraph \"lsmod\" {";;while(){@_=split/\s+/; print "\"$_[0]\" -> \"$_\"\n" for split/,/,$_[3]}print "}"' | dot -Tpng | display -
9-Create strong, but easy to remember password
read -s pass; echo $pass | md5sum | base64 | cut -c -16
10-Find all files larger than 500M and less than 1GB
find / -type f -size +500M -size -1G
11-Limit the cpu usage of a process
sudo cpulimit -p pid -l 50
很有“一行帝”风范啊～～