linux-cli-cheat-sheet

My personal clipboard of handy commands that I use frequently and that I tend to forget.

tmux (very) basic use

• Start new session: just tmux
• Detach: ctrl+b, d
• List current: tmux ls
• Attach: tmux attach-session -t 0

Easy format to search/replace text strings in many files using sed

SRC=Old Text here
DST=New Text here
find . *.php -type f -print0 | xargs -0 sed -i "/ipsum/s,$SRC,$DST,g"

(/ipsum/ selects lines containing "ipsum" and only on these lines the command(s) that follow are executed.)

Disk space usage analyser

ncdu

Linux find largest files

find . -xdev -type f -size +100M -print | xargs ls -lh | sort -k5,5 -h -r | head

Search only for files (-type f) in the current working directory (.), larger than than 100MB (-size +100M), don’t descend directories on other filesystems (-xdev) and print the full file name on the standard output, followed by a new line. The output of the find command is piped to xargs which executes the ls -lh command that will print the output in long listing human-readable format, and sorts lines based on the 5th column (-k5,5), compare the values in human-readable format (-h) and reverse the result (-r). head : prints only the first 10 lines of the piped output.

Linux find largest files and/or directories recursively

du -a | sort -n -r | head -n 50

Finds largest files and directories and lists largest 50, sorted on size.

Linux find files recursively larger than XXX

find . -type f -size +10M

find string of text in all files

grep -rnw '/path/to/somewhere/' -e "pattern"

Start Logrotate on Hypernode servers

/usr/sbin/logrotate -v /data/web/hypernode_logrotate.conf --state /data/web/.logrot_state

Simpler display of only bytes used and bytes free in Varnish (with varnishstat)

varnishstat -f SMA.s0.g_bytes -f SMA.s0.g_space

Varnish show updating list of top MISSes

varnishtop -i BereqURL

Varnish show updating list of all requests

varnishtop -i ReqURL

Varnish monitor purge requests

varnishlog -g request -q 'ReqMethod eq "PURGE"'

Send e-mail from command line CLI including setting from: header and bodytext

mail -a From:[email protected] -s 'Mail Testing lalala' [email protected] <<< 'Dit is het bericht. Over en sluiten.'

Tar complete directory, recursive, including hidden files, while preserving file permissions

tar -cvpzf FILENAME.tgz .

Auto-archive all pages in a sitemap to the Internet Archive's Wayback Machine (archive.org)

Install globally using npm install --global wayback-sitemap-archive

then run using: wsa <SITEMAP_URL>

One-line cache warmer using wget

1. Create one directory in home dir using mkdir ~/warmertmp.
2. Then run command: wget -U "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36" --directory-prefix=~/warmertmp --reject jpg,png --reject-regex "(.*)\?(.*)" --spider --recursive --no-directories https://www.DOMAINNAME.nl

You can also set this up in a cron job if you want.

Explanation:

--recursive will force wget to crawl the website recursively.

--spider is for "not downloading anything". However, this directive results in files created and deleted. Thus the following is useful:

--directory-prefix=~/warmertmp ensures that temporary files will end up in that temp dir.

--no-directories will ensure no empty directories are left out after running

--reject-regex "(.*)\?(.*)" This will fetch all pages, BUT will disregard everything after the ? -- so good for layered navigation, for example

Optional: --quiet is just a good way to silence any output to avoid cron email being sent.