What is Linux?
Linux is a clone of the operating system UNIX, written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the net. It aims towards POSIX and Single UNIX Specification compliance.
It has all the features you would expect in a modern fully-fledged Unix, including true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management, and TCP/IP networking.
Linux was first developed for 32-bit x86-based PCs (386 or higher). These days it also runs on (at least) the Compaq AlphaAXP, SunSPARC and UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 and CRIS architectures.
Linux is easily portable to most general-purpose 32- or 64-bit architectures as long as they have a paged memory management unit (PMMU) and a port of the GNU C compiler (gcc).
Some basic commands
Some basic linux commands, just practice them with all the information you got below:
| GNU/Linux/Unix commands A-Z | ||
|---|---|---|
| command | description | examples |
| bc | binary calculator | bc |
| cat | concatenate files and print on standard output | cat >test , cat file1 file2 >file3 |
| cd | change working directory | cd ~ |
| chmod | change file access permissions | chown guest.users filename |
| chown | change owner and group of a file | chmod u+x filename, chmod 770 filename |
| cmp | compare two files byte by byte | cmp file1 file2 |
| cp | copy a file or directory | cp -d -p -R |
| date | show system date | date |
| df | show free disk space | df -h |
| diff | find differences between two files | diff -u file1 file2 |
| du | show disk use of file(s) or directory | du -s |
| echo | display a line of text | echo "Hello world" |
| fg | bring a process to the foreground | fg [jobnr] |
| find | find files on name, date, owner, permissions etc | find ./ -name *.kdelnk |
| ftp | File transfer protocol | ftp ftp.nluug.nl |
| grep | print lines matching a pattern | ls -alR |grep txt |
| head | show first lines of text file | head textfile |
| irc | Internet Relay Chat | irc -c #squat fnord irc.xs4all.nl |
| jobs | show running or stopped jobs | jobs |
| kill | kill a process | kill -9 PID |
| killall | kill process by name | killall -9 netscape, killall -HUP daemon |
| less | a better version of more | less textfile |
| ls | list files in directory | ls -a -l -R |
| lynx | A text browser | lynx http://squat.net/ascii |
| Basic mail implementation | echo "Test" | mail -s "Test" guest | |
| man | show manual page on command | man command |
| mkdir | make directory | mkdir newdir |
| more | view text file screen by screen | more textfile |
| mv | move file or directory to another place | mv file1 file2 |
| ncftp | A better ftp client | ncftp -u username ftp.nluug.nl |
| netstat | Show network statistics | netstat -r |
| pico | edit a text file | pico filename |
| pine | A mail client | pine |
| ping | Send small package to check if a machine is up & reaction time | ping localhost |
| ps | show currently running processes | ps aux |
| pwd | print working directory | pwd |
| rm | remove a file or directory | rm -r -f |
| rmdir | remove directory | rmdir newdir |
| sort | sort a file | sort filename |
| ssh | A more secure version of telnet | ssh -l username host.domain |
| tail | show last lines of text file | tail -f textfile |
| telnet | Remote login | telnet dds.dds.nl |
| top | display top CPU processes | top |
| touch | change file timestamps | touch -t 10210000 filename |
| tr | translete or delete characters | echo "test" | tr [:lower:] [:upper:] |
| uniq | show only the diffenent lines from a text file | uniq filename |
| uptime | show the time the system is running (and system load) | uptime |
| vi | the unix text editor | vi filename |
| wc | count bytes, words and lines in files | wc -l filename |
| who | show who is logged on | who |
| whoami | print effective userid | whoami |
| yes | output a string repeatedly until killed | yes hello |
The best way to find information on how to use a command is the man command. This command tells you a lot of specific information on a command. Try man man for a start.
Some handy function keys
| Linux Function keys | |
|---|---|
| [CTRL]-z | Bring a program to the background |
| [CTRL]-c | Stop a program |
| [CTRL]-d | End of input file |
| [ALT]-[F1]..[F6] | Switch to terminal TTY1..6 (depends on configuration) |
| [ALT]-[F7] | Switch to X (if running) |
| [CTRL]-[ALT]-[F1..6] | Switch from X to text terminal |
| [CTRL]-[ALT]-[BACKSP] | Kill X-window (in mode 5, X will restart) |
| [CTRL]-[ALT]-[DEL] | Reboot or halt (depends on configuration) |
copied and extended from: PUSCII - # http://www.puscii.nl/
Related
--> Debian,GNU,[[::Category:Linux Distributions]],Linus Torvalds,FSF,Unix