| Command | Description |
| diff file 1 file2 | Compare files |
| rm -rf <dir> | Force delete of <dir> |
| shred -f -u <file> | Overwrite/delete file |
| touch -r <ref_file> <file > | Matches ref_file timestamp |
| touch -t YYYYMMDDHHSS <file> | Set file timestamp |
| sudo fdisk -l | List connected drives |
| mount /dev/sda# /mnt/usbkey | Mount USB key |
| md5sum -t file | Compute md5 hash |
| echo -n "str" | md5sum | Generate md5 hash |
| sha1sum file | SHA1 hash of file |
| sort -u | Sort/show unique lines |
| grep -c "str" file | Count lines w/ "str" |
| tar cf file.tar files | Create .tar from files |
| tar xf file.tar | Extract .tar |
| tar czf file.tar.gz files | Create .tar.gz |
| tar xzf file.tar.gz | Extract .tar.gz |
| tar cjf file.tar.bz2 files | Create .tar.bz2 |
| tar xjf file.tar.bz2 | Extract .tar.bz2 |
| gzip file | Compress/rename file |
| gzip -d file.gz | Decompress file.gz |
| upx -9 -o out.exe orig.exe | UPX packs orig.exe |
| zip -r <zipname.zip> \Directory\* | Create zip |
| dd skip=1000 count=2000 bs=8 if=file of=file | Cut block 1K-3K from file |
| split -b 9K ]<file> <prefix> | Split file into 9K chunks |
| awk 'sub("$"."\r)' unix.txt > win.txt | Win compatible txt files |
| find -i -name <file> -type *.pdf | Find PDF files |
| find / -perm -4000 -0 -perm -2000 -exec ls -ldb {} \; | Search for setuid files |
| dos2unix <file> | Convert to *nix format |
| file <file> | Determine file type/info |
| chattr (+/-)i <file> | Set/Unset immutable bit |
