note1

22122017 Command for LPIC-1 



uname - show what operating systems 
 -a show all

time - show run time for a command

set - set enviroment variables,

exit/ logout - exit any shell/only login shells

type - test command is it shell builtin or not
#care with the shell builtin and external command
(Exp: time and /usr/bin/time will show different output)

#shortcut#
C-f/Right arrow - move foward
C-b/Left arrow - move backward
C-p/Up arrow - previous command
C-n/Down arrow - next command
C-D - Delete character under cursor
C-x-Backspace - clear all text to cursor
C-K - clear from cursor to the end of the line
C-T - transpose two letter
C-R - search backward history command
C-S - search foward history command
C-A - move to beginning of line
C-E - move to end of line
Es-U - convert text from cursor to end of word to UPPERCASE
Es-L - conver text from cursor to end of the word to lowercase
Es-C - convert letter under cursor to uppercase


!! set -o vi - change bash keybindings form EMACS to vim 


history - show command history(history is stored in .bash_history)

 !! - show last command and executed
 !<number in history> - executed command form number in history
 -c - clear history

#~/.bashrc or /etc/profile is where shell configuration is stored
 
env - view entire environment variablesi

unset - unset variables 

man - view man pages for commands
 -k - find man from tags
 <section number> - show man from section

##man file section number
1 --> executables Programs
2 --> System calls from kernel
3 --> Library calls by program libraries
4 --> Device files(usually stored in /dev)
5 --> File formats
6 --> Games
7 --> Miscellanous
8 --> SysAdmin commands
9 --> Kernel Routines


info - new version of man ( can move from one section to others)

REDIRECTION /STREAMS/PIPES

STDOUT/STDIN/STDERR
Operator

>  - Creates file containing STDOUT . If exists overwrite
>> - Append STDOUT to file. If file doesnt exists its created
2> - Creates file containg STDERR . If exists overwrite
2>> - Append STDERR to file. IF file doesnt exists its created.
&> - Creates file containing STDOUT n STDERR,if exists overwrite
< - Send the content of files to be used as STDIN
<< - Accepts text on the following lines as STDIN( use in here doc)

<> - specified files is use for STDIN and STDOUT