Semicolons (;) are used in shell scripting and command-line interfaces to separate multiple commands, allowing them to be executed sequentially. When you use a semicolon between commands, the shell interprets it as a signal to execute the first command, and once that command completes (regardless of whether it succeeds or fails), it will proceed to execute the next command.
Example
Here’s a simple example:
echo "Hello"; echo "World"In this case:
- The first command
echo "Hello"is executed, which prints "Hello" to the terminal. - After the first command completes, the second command
echo "World"is executed, which prints "World".
Behavior
- Sequential Execution: Commands are executed one after the other in the order they are written.
- Independent Execution: The success or failure of one command does not affect the execution of the subsequent commands. All commands will run regardless of the outcome of the previous ones.
More Complex Example
You can also combine multiple commands that perform different tasks:
mkdir new_directory; cd new_directory; touch file.txt; echo "File created"In this example:
- A new directory named
new_directoryis created. - The shell changes into that directory.
- A new file named
file.txtis created. - A message "File created" is printed.
Using semicolons in this way allows for concise command chaining in scripts or command-line operations.
