Linux is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive Unix systems. Linux has a reputation as a very efficient and fast-performing system.
LINUX COMMANDS These few commands will: a) Tell us where we are, b) take us somewhere else, and c) show us what's there.
1)pwd -“Print Working Directory”. Shows the current location in the directory tree. Eg:fp088@pbs088:~$ pwd /home/fp088 2)cd-“Change Directory”. When typed all by itself, it returns you to your home directory. Eg:fp088@pbs088:~$ cd fp088@pbs088:~$ 3)cd directory-Change into the specified directory name. Eg: cd /usr/src/linux
4)ls-List all files in the current directory, in column format. Eg:fp088@pbs088:~$ ls Desktop Downloads Music Public Videos Documents examples.desktop Pictures Templates 5)clear-Clear the terminal screen 6)touch-Create empty file of zero byte Eg: fp088@pbs088:~$ touch aa 7)rm-Delete a file. Eg: fp088@pbs088:~$ rm aa 8)which-Shows the full path of shell commands found in our path Eg:fp088@pbs088:~$ which grep /bin/grep
9)locate-A quick way to search for files anywhere on the filesystem. 10)ps-Lists currently running process (programs). Eg:fp088@pbs088:~$ ps PID TTY TIME CMD 1797 pts/0 00:00:00 bash 2336 pts/0 00:00:00 ps 11)w-Show who is logged on and what they are doing. Eg:fp088@pbs088:~$ w 11:05:22 up 1:32, 2 users, load average: 0.01, 0.02, 0.01 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT fp088 tty7 :0 09:33 ? 3:58 0.19s gnome-session fp088 pts/0 :0.0 09:35 0.00s 0.27s 0.01s w 12)id-Print your user-id and group id's Eg:$ id uid=1000(fp088) gid=1000(fp088) groups=4(adm),20(dialout),24(cdrom),46(plugdev),104(lpadmin),115(admin),120(sambashare),1000(fp088)
13)df-Report filesystem disk space usage. Eg:~$ df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda1 73742752 2729736 67267064 4% / udev 997964 208 997756 1% /dev none 997964 1540 996424 1% /dev/shm none 997964 88 997876 1% /var/run none 997964 0 997964 0% /var/lock none 997964 0 997964 0% /lib/init/rw 14)echo-Display text on the screen. Eg:echo "hello World" hello World 15)date-date to set your server's date and time 16)finger-Use finger to see who's on the system Eg:~$ finger Login Name Tty Idle Login Time Office Office Phone fp088 fp088 tty7 May 20 09:33 (:0) fp088 fp088 pts/0 May 20 09:35 (:0.0)
17)cal-displays a calendar Eg:$ cal May 2010 Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 18)ls -al List all files in the current working directory in long listing format showing permissions, ownership, size, and time and date stamp 19)more-Allows file contents or piped output to be sent to the screen one page at a time. <ls -al |more> 20)mv-Move or rename files mv -i myfile yourfile Move the file from "myfile" to "yourfile". This effectively changes the name of "myfile" to "yourfile". 21)shutdown -Shuts the system down. <shutdown -h now> Shuts the system down to halt immediately.
22)whereis-Show where the binary, source and manual page files are for a command <whereis ls> Locates binaries and manual pages for the ls command. Eg:~$ whereis ls ls: /bin/ls /usr/share/man/man1/ls.1.gz fp088@pbs088:~$
cooledit - a pretty powerful GUI text editor
jed - has pretty good emacs emulation (it can even read mail like emacs!). It does simple syntax highlighting for TeX files, including giving positioning of parentheses.
It would seem to be pretty configurable and takes up much less disk space than emacs, although more than joe and muemacs. It works well in console mode, and still manages to use colors for menu bars and syntax highlighting.
The program xjed which comes with some versions starts up its own X terminal when invoked.
joe - "Joe's Own Editor", a fairly powerful editor with a compact binary and an ability to emulate Wordstar, Emacs, Pico, and a few other editors.
jove - "Joe's Own Version of Emacs". I tried this out a couple of times and managed to crash it when making some minor errors in command syntax.
microemacs (JASSPA) - spinoff of muemacs. Pretty powerful and configurable, while not taking up too much disk space or memory.
muemacs - a fairly powerful emacs clone whose binary is actually smaller than that of the Joe editor.
emacs - powerful text editor that includes modules for reading and sending mail and postings to newsgroups, and a browser module. For editing TEX and LATEX files, the AucTEX addon package is invaluable, and makes emacs pretty hard to beat as an editor with LATEX.
nedit - an X Window based text editor. Of all text editors for Linux , it has commands which are closest to Windows text editors, for cursor movement, highlighting, marking text, etc. It has very good syntax highlighting for both LATEX and HTML. pico - simple text editor. It often comes packaged with the Pine mail user agent. vi - included with most Linux distributions. If you're not used to the syntax, it can be pretty hard to understand. vim - improved version of vi xedit - simple text editor included with many Linux distributions
/ Root |---root The home directory for the root user |---home Contains the user's home directories | |----ftp Users include many services as listed here | |----httpd | |----samba | |----user1 | |----user2 |---bin Commands needed during bootup that might be needed by normal users |---sbin Like bin but commands are not intended for normal users. Commands run by LINUX. |---proc This filesystem is not on a disk. Exists in the kernels imagination (virtual). This directory | | Holds information about kernel parameters and system configuration. | |----1 A directory with info about process number 1. Each process | has a directory below proc. |---usr Contains all commands, libraries, man pages, games and static files for normal | | operation. | |----bin Almost all user commands. some commands are in /bin or /usr/local/bin. | |----sbin System admin commands not needed on the root filesystem. e.g., most server | | programs. | |----include Header files for the C programming language. Should be below /user/lib for | | consistency. | |----lib Unchanging data files for programs and subsystems | |----local The place for locally installed software and other files. | |----man Manual pages | |----info Info documents | |----doc Documentation for various packages | |----tmp | |----X11R6 The X windows system files. There is a directory similar to usr below this | | directory. | |----X386 Like X11R6 but for X11 release 5 |
---boot Files used by the bootstrap loader, LILO. Kernel images are often kept here. |---lib Shared libraries needed by the programs on the root filesystem | |----modules Loadable kernel modules, especially those needed to boot the system after | disasters. |---dev Device files for devices such as disk drives, serial ports, etc. |---etc Configuration files specific to the machine. | |----skel When a home directory is created it is initialized with files from this directory | |----sysconfig Files that configure the linux system for networking, keyboard, time, and more. |---var Contains files that change for mail, news, printers log files, man pages, temp files | |----file | |----lib Files that change while the system is running normally | |----local Variable data for programs installed in /usr/local. | |----lock Lock files. Used by a program to indicate it is using a particular device or file | |----log Log files from programs such as login and syslog which logs all logins, | | logouts, and other system messages. | |----run Files that contain information about the system that is valid until the system is | | next booted | |----spool Directories for mail, printer spools, news and other spooled work. | |----tmp Temporary files that are large or need to exist for longer than they should in | | /tmp. | |----catman A cache for man pages that are formatted on demand |---mnt Mount points for temporary mounts by the system administrator. |---tmp Temporary files. Programs running after bootup should use /var/tmp.