Useful Linux Commands in collaboration with Abdul Barek

Linux Commands.txt

Copy directory to remote server from remote server
scp -r sourcedir/ user@dest.com:/dest/dir/

Run a scheduled rake task(lets say update sphinx indexing on every 30 min periodically) on Lunux crontab:
# find where is your rake(which rake)
#m h dom mon dow user  command
*/30 * * * *  root /bin/bash -l -c 'searchd --stop -c /var/rails/project/current/config/production.sphinx.conf && cd /var/rails/project/current && RAILS_ENV=production /usr/local/bin/rake ts:rebuild && chmod -R 777 tmp/'

Create Symbolic link(Short cut)
ln -s /source/dir destination/dire/short_cut_name
ln -s -f /source/dir destination/dire/short_cut_name

truncate a file(0 means how many character you wanna keep)
truncate -s0 /path/to/file

see a file's last portion on real time
tail -f path/to/file

See a folder's size
du -hs /path/to/folder

See a file size
du /path/to/file -h

See full disc size
df -h

Search file with pattern and delete them (from a specific directory)
find . -name 'file_name_pattern*' -delete
find . -name '*file_name_pattern' -delete

find running process and kill them by process id forcefully
ps aux | grep rails
kill -9 RAILS_PROCESS_ID

Zip a folder
zip -r new_zep.zip /folder/path

untar a gz file
tar -xvzf file.tar.gz

Remove recursively a folder's content(keeping the folder itself)
rm -rf /path/to/folder/*

Download
wget download_url -O new_downloaded_file_name


Copy a folder
cp -r  source/dir destination/dir

To know 32 or 64 bit Linux machine
uname -a

To know Ubuntu version
lsb_release -a