Differences between source, sh, bash, and./script execution in ubuntu

Differences between source, sh, bash, and./execution scripts in ubuntu source command usage: sourceFileName function: read and execute commands in FileName in the current bash environment. This filename File may not have the & quot; execution permission & quot; Note: this command is usually replaced by the command .... Differences between source, sh, bash, and./execution scripts in ubuntu source command usage: source FileName function: read and execute commands in FileName in the current bash environment. This filename File may not have the "execution permission" Note: this command is usually replaced by the "." command. For example, source. bash_profile www.2cto.com.. bash_profile is equivalent to both. The source (or vertex) command is usually used to re-execute the modified initialization document. The source Command (from the C Shell) is the built-in command of the bash shell. The Dot Command is a dot symbol (from the Bourne Shell ). The main body of the source program is bash, and the value of the $0 variable in the script is bash. because it acts on the current bash environment, the set variable in the script will directly take effect.
2 sh, bash command usage: sh/bash FileName function: open a sub-shell to read and execute the command in FileName. This filename File may not have the "execution permission" Note: when running a shell script, another command interpreter is started. each shell script runs effectively in a sub-process of the parent shell (parent shell. this parent shell refers to a process that provides command indicators to you on a control terminal or in an xterm window. shell scripts can also start their own sub-processes. these sub-shells (that is, sub-processes) allow scripts to run multiple sub-tasks in the script in parallel and efficiently. in ubuntu, sh is just a link to bash. Because www.2cto.com is executed in the sub-shell, the variables set by the script do not affect the current shell.
3../command usage:./FileName function: open a sub-shell to read and execute the command in FileName. The filename File requires "execution permission". note: when a shell script is run, another command interpreter is started. each shell script runs effectively in a sub-process of the parent shell (parent shell. this parent shell refers to a process that provides command indicators to you on a control terminal or in an xterm window. shell scripts can also start their own sub-processes. these sub-shells (that is, sub-processes) allow scripts to run multiple sub-tasks in the script in parallel and efficiently. because it is executed in the sub-shell, the variables set by the script do not affect the current shell. Author Tender001