Linux Shell Application Tips

<span style= "FONT-SIZE:14PX;" >--------------------------------------  Shell application Tips------------------------------------------A command completion: Tab completion shell command two: Clear or ctrl+l clean screen ctrl+u Erase all previous contents of the cursor history List all the commands you've knocked. Name alias definition: Alias View alias COPY=CP the next time you copy the line alias xrm= "rm-r" unalias copy delete alias Input output redirect (very many shell scripts) 0 (stdi n) standard input 0<1 (stdout) standard output 1>2 (stderr) standard error output 2>a:> output redirect Ls-l/tmp >/tmp.msg put the results of the ls-l command into the/TMP/TM P.msg, redirect information to a file more/tmp.msg the contents of the directed file can be knocked after: Data >/tmp.msg you will find that the above redirected content has been overwritten with data >>/tmp. Msg This will append the content to the redirect content above b:< input REDIRECT Wall </ETC/MOTD broadcast file content, MOTD is to broadcast the content in advance written c:2> error output redirection (2> indicates an error) u The SR directory is equivalent to the Windows directory, the core directory of the system cp-r/usr/backup/usr.bak 2>/bak.error Copy directory (2 for execution when command error) example: LS xxxxxxx a nonexistent file ls/xxxxxx X 2> ls.err when the LS command fails, the error message is left in the wrong file inside the pipe explanation: the output of one command to another command, as an input to another command, use the method command 1| command 2| command 2|.....| Command N (multiple commands can be connected) Example: ls-l/etc | More the content pipeline of LS output to more paging view ls-l/etc | grep init pipes The LS command content to grep View init files only Ls-l/etc | grep init | Wc-l See how many (multiple pipe) command connectors are in the ETC directory for the init file 1; Interval commands are executed one at a time 2 && (connecting 2 commands) The execution of the preceding command has a logic and relationship, and only after the previous command of && has been successfully executed, Before you perform the following command 3 | | (Connect 2 commands) The execution of the command has a logical or relationship, only | | After the execution of the preceding command fails, the following command is executed example: 1 pwd; LS; The Data 3 command executes the 2 scene in turn: The machine gives you the technology you like. Write a love letter and delete write mm 
Linux Shell Application Tips