| ls -1 | wc -l | Count number of files in current directory |
| grep -rni "anystring" --include "*.f90" | Search for string in all f90 files |
| find . | grep png | Search for all png files in all subfolders |
| top -u user | top for specific user |
| head/tail -n 5 filename | Prints first/last 5lines of file |
| rm -rf dir | Remove directory 'dir' and all files within dir (-f force delecte without prompt) |
| df -h | File system disk space usage |
| du -sh . | Size of the content of currcent directory |
| tar -xzf filename.tar.gz | Extract compressed file |
| find . -type f -size 1000c | Type file of size 1000 byte |
| ps -eo pid,lstart,cmd | grep procname | Show starting time of all running processes; ps - report a snapshot of the current processes. |
| emacs filename -nws | Open emacs in terminal |
| nload | Check network traffic (left and right arrow to change device) |
| last | grep user | head -n 10 | Check last 10 logins in server via ssh |
ldd execname OR
objdump -p execname | grep NEEDED | Check executable dependencies |
| ldconfig -p | grep libraryname | Check installed libraries |