Wednesday, January 16, 2013

Vim Advanced Text Editor

Vim is a text editor written by Bram Moolenaar and first released publicly in 1991. Based on the vi editor common to Unix-like systems, Vim is designed for use both from a command line interface and as a standalone application in a graphical user interface. Vim is free and open source software,The name "Vim" is an acronym for "Vi IMproved"[6] because Vim is an extended version of the vi editor, with many additional features designed to be helpful in editing program source code.


Vim also has a built-in help facility (using the :help command) that allows users to query and navigate through commands and features.

VIM An Advanced Text Editor:-
=> Newer Virsion of VI, the standard Unix text editor

=> gvim :         Graphical Version of vim


SPEED            : Do more with fewer keystrokes
Simplicity        : No dependence on mouse/GUI
Availability      : Included with most Unix-like OSes

Difficulty         : Stteper learning curve than simpler editors

Three Main Mode :-
Command Mode     : Move cursor, cut/paste text, change mode
Insert Mode            : Modify text
Ex Mode                 : Save, quit, etc

'Esc' key is used to exits current mode.

'EscEsc' always returns to command mode.

=> vim abc.txt        : can edit the text file if existing or not
=> vim /etc/passwd
=> vim /tmp/file

       : begins insert end of line
    : Append to end of line
     : Insert at beginning of line
(small)    o    insert new a line (below of current line)
(caps)    O    insert new line ( above of current line )

EX MODE with ( : ) :-
    :w       : writes (saves) the file to disk
    :wq     : writes and quits
    :q!      : quits, even if changes are lost ( do not save )

COMMAND MODE ( Default Mode ) :-
    Right Arrow         ( -> )     moves right one character
    5, Right Arrow     ( 5 ->) moves right five (5) character

    h    move cursor to left
    j     move cursor to down
    k    move cursor to up
        move cursor to right

    w    move cursor by word ( forward )
      move cursor by word ( backward )   
    (     move cursor by sentense ( forward )
    )     move cursor by sentense ( backward )

    /xyz    search the 'xyz' into the file  (n,N) use for next,prev

This command will run in file --------------- {vi /xyz (filename)}
    :%s/macho/dud/gi    search & replace all macho to dud (gi- globely)
    :1,5s/sam/sandy/      search & replace from line-1 to line-5

    :5        move cursor to line no. 5
    :G       move cursor to the end of document
    dd       to delete current line
    4dd     to delete four line
    yy       to copy the line
    5yy     to copy five line
    p/P      paste the copied line or text 
    u         undo 
   ctrl r    redo

    :set number    set the line number in file
    :set nonu    remove the line number in file

NOTE ( try must / read must / do must )

if you have any query about vim    please try 'vimtutor' command in terminal not in file

Vishal Vyas

Wednesday, January 9, 2013

Browsing linux filesystem

Browsing The Filesystem

Some Important Directories
Red hat root (main)directory: /
Home Directories:                /root                       ( home directory of root only )
                                            /home/username      ( for all users )
User Excecution :                /bin, /usr/bin, /usr/local/bin
system Excecution :             /sbin, /user/sbin, /usr/local/sbin
Other Mountpoints :             /media, /mnt
Configuration :                     /etc
Temporary files :                  /tmp
Kernels and Bootloader      /boot
Server Data :                      /var, /sys
System Information :           /proc, /sys
Shared Libraries :               /lib, /usr/lib, /usr/local/lib

=> pwd                                 to see current working directory
Note :   1) Names may be up to 255 characters
                2) All characters are valid, except the forward-slash
                3) Names are case-sensitive

=> mkdir dirname             to make a dir

=> mkdir 1 2 3 4              to make multipal dir

=> mv o-name n-name      to rename dir

=> touch filename             to make a empty file

=> touch {a,s,d,f}.{jpg,doc,mp3}

=> mv o-name n-name     to rename file

=> vi filename                   to see or edit the file

=> cat filename                 to see the contant of file
(cat > , cat >>)

=> nano filename              to edit in text file
=> cd dirname                  to change dir
=> cd ..                            to a directory one level up
=> cd                               to goto home directory
=> cd -                             to your previous directory
=> ls -a                             to list of file and dir with hidden file 
=> ls -l                              to see long listing of file and dir (ll)

=> cp sourcefile destination             ( cp file1 /home/macho )
                to copy file

=> cp -r sourcedir destination          ( cp -r dir1 /home/macho )
                to copy dir recursively   

=> cp -r -v sourcedir destination     ( cp -r -v dir1 /home/macho )
                to copy dir & show process         

=> mv sourcefile destination            ( mv file1 /home/macho )
                to move file into elesewhere

=> mv dirname destination               ( mv dir1 /home/macho )

=> rm filename                                 (to remove any file)

=> rm -rf *.mp3                               (to remove all file which extension .mp3)

=> rmdir directoryname                    ( to remove dir )

=> Backing-up your system configuration
       -mkdir /root/backups-20100415
      -cp -r -v /etc/sysconfig /root/backup-20100415

Vishal Vyas
Linux guru.

Basic linux commands

==>>>   Command


                - date                          : to see the date and time
                - date 112503451982 : month,date,hour,minut,year                        
                - cal                            : to see the calendar
                - cal 2010                   : to see the calendar of 2010
                - cal 5 2010                : display the calendar of May 2010                                        
                - clear                         : to clear the screen
                - ls                              : to see the list of dir and file                   
                - useradd vishal           : to create user with name 'vishal'
                - passwd vishal            : to set & also change password of user 'vishal'
                - passwd                     : to root only

                - passwd -d vishal                  : create user without password
                - usermod -l n-name o-name  : to rename user
                - usermod -g group user         : to add user in group
                - useradd -n vishal                  : create user without duplicate directory
                - userdel vishal                        : to delet user
                - userdel -r vishal                    : Delet user with their directory
                - rm -rf directory                    : forcefuly remove directory

                - groups vishal                         : to see membarship of user
                - vi /etc/passwd                       : see user directory
                - groupadd sels                        : create group
                - vi /etc/group                          : see group directory

                - groupmod -n n-name o-name  : rename group

                - su macho           : to login one user to other user (sudo passwd vishal)
                - system-config-   : to see graphycaly any configuration
                - ctrl+shift-t          : create a new Tab
                - ctrl+PgUp/Dn    : Switch to next/prev
                - /usr/share/doc    : to see file of any command
                 (cp,cd & ls -l    /usr/share/doc/HTML/index.html)

                - whatis cal           : to see help about any calendar
                - date --help         : to see detailed help about date
                - man ls                : to see manual page about ls
                - info history         : to information of history
                - which dir            : to find path of any directory & command

=> Tilde ( ~ )     (May refer to your home directory)
                           cat ~/.bash_profile
                           ls ~sam/public_html


=> system-config-date                  to set date & time graphicaly

=> history     (this command is used to see recently used command)

=> ping
=> ping -w4
=> ping -c4 > test
=> ll >>test

=> renice 5 PID          reduce the priority

=> kill 3428                used to kill particular process with pid

=> top (CLI)              used to see process list, memory and cpu uses

=> gnome-system-monitor    ( GUI ) 

=> ctrl+c                     fully stop

=> ctrl+d                    stop terminal

=> ctrl+z                     send the program into background or temp. halt (ping,firefox)

=> jobs                       used to check the program running into back.

=> fg 1 or 2 or 3         used to bring halt program to rerun

=> at 0630                  to schedule these all jobs at 06:30

   > mkdir /root/Desktop/macho
   > useradd macho
   > ls -l
   > ctrl+d
Note : at command runs programme only ones at particular time

=> atq                         to see pending jobs

=> atrm 4                    to remove job-no. 4

=> crontab -e              this command is used to execute the job
            manytime as you want (chep-4)

=> who | wc -l > abc.txt    example of grouping multi command

=> date; who | wc -l >> abc.txt     grouping command

=> $?                used to check the last command status
            0     for     success
            1-255     for     error  

 => date 010101012010

                month  : MM
                date     :  DD
                hours   :  hh
                minute  : mm
                year     : YY
above example will set the date

 1st of JAn, at 01:01:01am. and the Year 2010

                - startx  : initialize an X session (if ur mode in text through this command u can get Graphical mode).

Vishal Vyas

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