# LaTeX Terminal Input and Output

You can send messages to and read from the terminal.

### \typeout

``` \typeout{msg}
```

LaTeX's usual rules for treating multiple spaces as a single space and ignoring spaces after a command name apply to msg. A \space command in msg causes a single space to be printed.

### \typein

``` \typein[cmd]{msg}
```
Prints msg on the terminal and causes LaTeX to stop and wait for you to type a line of input, ending with return. If the cmd argument is missing, the typed input is processed as if it had been included in the input file in place of the \typein command. If the cmd argument is present, it must be a command name. This command name is then defined or redefined to be the typed input.