Copying files and directories

• cp manual Duplicate an entire directory including subfolders cp -r SRC DEST
• Create a symbolic link to a file cp -s FILE NEWLINK (equivalent to ln -s FILE NEWLINK)
• Create a hard link to a file cp -l FILE NEWLINK (equivalent to ln FILE NEWLINK)

Getting information

• stat manual Print last access time, modify time etc. stat FILE
• du manualShow summary size of a directory in human language du -sh DIR
  • Exclude certain files --exclude=’*.o’ (pattern is a shell pattern)
• find manual Count files in a directory find DIR -type f | wc -l (or use ncdu)

Looking in files

• cat manual Number the lines in a file cat -n FILE
  • nl manual A more sophisticated version of the above nl file
• head manual Show first N lines of a file head -3 FILE
• tail manual Show last N lines of a file tail -3 FILE
• Follow modifications to a file and finish when the process terminates tail –pid=PID -f FILE

Manage permissions and owners

• chmod manual Change permissions of a file chmod
• chown manual Change the owner of a file chown
• chgrp manual Change the group owner of a file chgrp

Misc

• xdg-open manual Open any file from the command line in its associated program xdg-open FILE