Linux学习笔记 1 环境变量 2 vi命令

1 环境变量篇

1.1  修改 查看 生效 系统环境变量

    1 涉及系统环境变量的文件   -->  .bash_profile

　　　　　　　　　　　　　　 -->　/etc/profile

    2 该文件位置 /root/.bash_profile

    3 文件编辑器打开  vi .bash_profile

    4 文件末尾加入 

                    

JAVA_HOME = /usr/share/jdk 1.6.0

PATH = $JAVA_HOME/bin:$PATH

CLASS_PATH=.$JAVA_HOME/lib/dt.jar：

$JAVA_HOME/lib/tools.jar



export JAVA_HOME

export PATH

export CLASSPATH



5 文件生效

       source /root/.bash_profile

6 验证环境变量

      export JAVA_HOME

         echo $JAVA_HOME

 

VI 命令篇章

 输入指令 a 

  退出指令 :q  强退：q!   保存且退出 :wq

                                    存成新文件  :w newfile



查找指令  : ？____   <要查找的单词>

                 /  ____  要查的词

           n    finding the dedicate word then moving to the next

                N    oppersite direction

                :set nu <---show the line number  

                :set nonu <---remove line number





direction :

                 k

             h   j  l



input: i  insert in front of the cursor 

         a insert behind the cursor

         o  insert in the next line of the cursor 



delete:

             x:delete the char of the cursor

            X :delete the char of the cursor



            dd:delete the current row

            5dd:delete the currrent line and the next 5 line

            :1,5d delete1 to 5 line

            x delete one charactor





vi substitute

:s /cici/titi         replace the line cici with titi

:s/cici/titi/g       replace all the cici with titi in the current line

:n,$s/cici/titi    the line n to the last line.each line cici replace with titi

:n,$s /cici/titi/g  the line n to the last line.each line cici replace with titi

:.,$s/cici/titi     replace all the words in the passages from the first line 

                     to the last line

 

repalce confirmation command.adding character c behind the comma



:s/cici/titi/gc  all the cici replace with titi  + confirmation

show line number :set nu





dw  delete current words

3dw delete 3 words



copy and attach



yw  copy word

y5w copy all 5 words

yy copy all the line 

5yy copy 5 lines

p copy after the current line

:1,2co3 copy from line1 to line2 after line 3

:4,5m6

          1          1

          2          2

          3          3

          4          6

          5          4

          6          5



location command

              gg moving to the front of the file

              G moving to the end of file 

              :20 moving to line 20

              J  merge 2 line

              shift + 8 :

                             finding the word which is in the position of cursor