source

Reads and executes commands from the specified file in the current shell environment.

Summary

source filename [arguments]

The main purpose

Execute the file and load variables and functions from the file into the execution environment

Parameters

filename: file to be executed

arguments (optional): parameters passed to the file

return value

source returns the return value of the last command in the file. It will fail if the file cannot be read.

Incorrect usage

File not found in $PATH.
Document not given.

example

During the execution of some tools, the environment variable settings will be exported to into a file, and then use source to load the contents of the file into the execution environment.
Read and execute the /root/.bash_profile file.

[root@localhost ~]# source ~/.bash_profile

Q&A

Q: What is the difference between source and sh in executing files?

A: sh is executed in a subshell. source will cause the variables and functions of the executed file to be loaded into the current terminal environment (excluding variables modified by local in the function, etc.); it is recommended that you refer to the export command. Knowledge Points Section