General Linux commands

OverviewRead the “ Overview ” section

This page covers general commands using Linux. Not specific to any program, some could be used for debugging, others might be validating something or simply getting some info about a running process.

Find out how many lines a file contains a phraseRead the “ Find out how many lines a file contains a phrase ” section

cat /var/log/app.log.2 | grep "api/users" | wc -l

Curl request detailsRead the “ Curl request details ” section

Curl a request with form-data uploading a file using and get some speed info

curl -w '\nEstablish Connection: %{time_connect}s \
  \nTTFB: %{time_starttransfer}s\n  \
  Total: %{time_total}s\nUpload speed: %{speed_upload}s\n' --http2  \
  --location --request POST 'https://www.somedomain.com/uploadfile' \
  --header 'Authorization: Bearer HwzQAS323DvAGQ23123' \
  --form 'file=@/home/some_file.csv' \
  --form 'file=@/home/another_file.csv'

This specific thing is important due to the nature of how HTTP2 works, uploading files could be slower unless you tune your web-server HTTP2 initial window. Try it with HTTP1.1 and see the difference

curl -w '\nEstablish Connection: %{time_connect}s \
  \nTTFB: %{time_starttransfer}s\n \
  Total: %{time_total}s\nUpload speed: %{speed_upload}s\n' --http1.1 \
  --location --request POST 'https://www.somedomain.com/uploadfile' \
  --header 'Authorization: Bearer HwzQAS323DvAGQ23123' \
  --form 'file=@/home/some_file.csv' \
  --form 'file=@/home/another_file.csv'

You can refer to the write out command in Curl (You can find it Nuggets section too)

Network speed testRead the “ Network speed test ” section

Check network speed of the host you are in, this is very useful to get actual results about the bandwidth of say your VPS server or your home setup.

sudo ln -s /usr/bin/python3 /usr/bin/python
curl -s https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py | python -

Disk usageRead the “ Disk usage ” section

Check hard drives disk usage size on your machine, or the host you logged into.

The whole drive

df -h

The current directory

du -sh *

Tailing logsRead the “ Tailing logs ” section

tail all incoming new lines for log file(s)

tail -f -n0 *-error_logs.log

Find file(s)Read the “ Find file(s) ” section

Find if file(s) exists in the current directory/sub-directories, and list found file(s) locations

Note: This needs sudo to look in directories that requires root permission, it will also list of all files and directories in the current directory if it finds nothing, I will look into it and fix later.

find . -name "*-logs.json" | xargs ls -lh

process(es) detailsRead the “ process(es) details ” section

Find if process(es) are currently running, and list process(es) details (root process/child processes) if found

ps aux | grep mysql

manage service(es) with different usersRead the “ manage service(es) with different users ” section

sudo -u www-data service nginx start
sudo -u omar service netdata restart

All topicsRead the “ All topics ” section

• General Linux commands
• Docker Commands
• MySQL Commands
• MongoDB Commands
• PHP Commands