vi <file_name.sh> (enter file)
ESC MODE : esc
EDIT MODE
replace : r or double insert
insert : i or insert
VISUAL MODE : v
use shebang/header line at begining >> #!/bin/bash
<<DOC <..> DOC- command multiple lines
# = command single lines
BASIC FILE OPERATIONS
save - Esc + :w
quit - Esc + :q!
save and quit - Esc + :wq
SHORTCUTS TO BE DONE IN ESC/COMMAND MODE
copy : yy
copy multiple lines : 'n'yy (top to bottom)
paste : p
delete : dd or 'n'dd (multiple)
delete one line : dw
delete starting cursor position to end : d$
delete before cursor position : d^
undo : u
redo : ctrl + r
go to first line : gg
go to last line : G
go to a particular line nG or ngg
create new line after cursor position : o
" before cursor position : O
Replace a specific world without entering the replace mode - :%s/wor/new word
TO COPY FROM ONE FILE TO ANOTHER : ESC MODE >> :r <file_name.sh>
MANUAL - vimtutor
COMMANDS
set nu (give numbering to the lines)
set hls (to hightlight lines) incsearch >> to highlight >> Esc + /<word>
set mouse=a (to move using mouse)
a - work in all mode
To make permanent changes >> cd ~ (reach root directory) >> vi .vimrc >> <type in
commands for changes here>
wc <option><file_name.sh>
to get total word count in a file : wc -w <file_name.sh>
to get total line count in a file : wc -l <file_name.sh>
to get total byte/character count in a file : wc -c/m <file_name.sh>
take word byte and line count from terminal
wc >> ENTER >> <typein> >> Ctrl+D
DISPLAY FILE CONTENTS IN TERMINAL
cat <file_name>
head <file_name> : prints first 10 lines
head -3 <file_name> : prints first 3 lines
head -c3 <file_name> display first 3 characters
