First shell script

Open a text editor, create a new file with the extension sh (sh for Shell), the extension does not affect the execution of the script, see the name of the good idea.

#!/bin/bashecho"Hello world! " "

"#!" is a contract tag that tells the system what interpreter the script needs to execute, even if it uses a shell.

As an executable program

Save the above code as test.sh and CD to the appropriate directory:

chmod +x./test. SH   #使脚本具有执行权限. /test. SH  #执行脚本

Note, be sure to write./test.sh, not test.sh. Run other binary programs also, the direct write Test.sh,linux system will go to the path to find there is not called test.sh, and only/bin,/sbin,/usr/bin,/usr/sbin, etc. in path, your current directory is usually not in path, So write test.sh will not find the command, to use./test.sh tells the system that it is looking in the current directory .

To run the bash script this way, the first line must be written so that the system can find the correct interpreter.

As an interpreter parameter

This works by running the interpreter directly, whose parameters are the file names of the shell scripts, such as:

/bin/sh test. SH

The script that runs this way does not need to specify the interpreter information in the first line, and it is useless to write.

Instance

#!/bin/bashecho"What isyour name? " " Read person Echo " Hello, $PERSON "

To run the script:

chmod +x./test. SH $. /test. SH What is your name? Mozhiyanhello, mozhiyan$

First shell script