Linux and UNIX Systems Configuration Help, How To, Tutorial and Basic Information

1. tar

Command tar Creates archive files or extract files from archives. Syntax tar [options] file_or_directory Options -c creates a new archive. -d compares the files from the archive files from the ...

2. tail

Command tail Displays the last few lines of the file. Syntax tail [options] file Options -N (where N - number) displays the last N lines. -n N (where N - number) displays the last N lines. -f ...

3. rmdir

Command rmdir Deletes the specified directory (if it is empty). Syntax rmdir [options] directory Options -p remove all parent directories which become empty. Description The command rmdir ...

4. rm

Command rm Removes one or more files. Syntax rm [options] files Options -f deletes files without asking. -i asks for confirmation before deleting files. -r recursively deletes files in all subdirectories ...

5. pstree

Command pstree Displays all running processes in a tree. Syntax pstree [options] [process_id] Options -a displays the command line arguments. -c does not compress the subtrees. -l displays a long ...

6. ps

Command ps Displays the status of processes (programs) running in the system. Syntax ps [options] Options Note that unlike other commands ps command options do not have a prefix "-". a display ...

7. mv

Command mv Renames files and directories or move them from one directory to another. Syntax mv [options] source destination Options -b creates backup copies of files that are moved or renamed. ...

8. more

Command more Performs view text files. Syntax more [options] file_names Options +N (where N - number) displays the file, starting at the specified line number. +/pattern begins with a display ...

9. man

Command man Print page operational manual (also called man-pages). Syntax man [options] [section] command Options -C conf_file indicates configuration file man (by default /etc/man.config). -p ...

10. mkdir

Command mkdir Creates a directory. Syntax mkdir [options] directory_names Options -m access appoints new directory specified access rights. -p creates parent directories if they do not exist. ...

11. ls

Command ls Prints the contents of the directory. Syntax ls [options] [directory-names] Options -a displays all files, including those with names starting with a dot (.). -b displays unprintable ...

12. ln

Command ln Sets hard or symbolic links (aliases) for files and directories. Syntax ln [options] existing_file new_name Options -b backs up files before deleting them. -d creates a hard link to ...

13. less

Command less less command displays text files (with the possibility of searching through back). Syntax less [options] file_name Options -? displays a list of commands that can use less. -p displays ...

14. ldd

Command ldd ldd command displays the names of shared libraries required for execution. Syntax ldd [options] program Options -v displays the version number of ldd. -V displays the version number ...

15. killall

Command killall killall command kills all active processes. Syntax killall [options] Options view option kill command Description Command killall kills all active processes. Implied value ...

16. kill

Command - kill Kill command sends a signal to the process. Syntax kill [options] id_process Options -Nsignal sends a specified signal (where Nsignal - the number or name). -l displays the number ...

17. info

Command info info command displays online help for any command Linux. Syntax info [options] command Options -d add the directory to the list of directories in which files are being explored.  ...

18. id

Command id Id command displays the user ID, group ID and user groups. Syntax id [options] [username] Options -g prints only the group ID. -n displays the name of the group, rather than group ...

19. head

Command head head command displays the first few lines of a file to standard output. Syntax head [options] file Options -n nline number of displayed rows. Description Displays the first line ...

20. gzip

Command gzip gzip command compress one or more files. Syntax gzip [options] files Options -c displays the output file to standard output and keeps the original file. -d decompresses the file (same ...