## 2.3 `<` command

### 2.3.1 Syntax

`<` filename
`<<` filename

### 2.3.2 Purpose

Run a simulation in batch mode. Gets the commands and circuit from a disk file. `<<` clears the old circuit, first.

### 2.3.3 Comments

You can invoke the batch mode directly from the command that starts the program. The first command line argument is considered to be an argument for this command.
The file format is almost as you would type it on the keyboard. Commands must be prefixed with a dot, and circuit elements can be entered directly, as if in build mode. This is compatible with Spice.
The `log` command makes a file as you work the program, but the format is not correct for this command. To fix it, prefix commands with a dot, and remove the `build` commands.
Any line that starts with `*` a comment line.
Any line that starts with `.` (dot) is a command.
Any line that starts with a letter is a component to be added or changed.
A `<` command in the file transfers control to a new file. Files can be nested.
A bare `<` in the file (or the end of the file) gives it back to the console.
Unlike SPICE, commands are executed in order. This can result in some surprises when using some SPICE files. SPICE queues up commands, then executes them in a predetermined order.

### 2.3.4 Examples

`< thisone.ckt`
  Activates batch mode, from the file `thisone.ckt`, in the current directory.
`< runit.bat`
  Use the file `runit.bat`.
  From the shell: on start up:
`gnucap afile`
  Start up the program. Start using the file `afile.ckt` in batch mode, as if you entered `< afile` as the first command.
`gnucap <afile`
  Start up the program. Start using the file `afile.ckt` with commands as if you typed them from the keyboard.