BSH The B grade shell syntax

This is a text file containing some informations on the syntax of bsh scripts, and on some commands either internal to bsh, or used by prol.

Basics

A command looks like the following: command arg1 arg2 ... where arg1, arg2, etc. are strings of text separated by spaces or enclosed in single/double quotes. Commands must be followed by a space if other characters must be written after it.

Commands are closed by a newline or a semicolon. Newlines can be escaped with a backslash, which will translate them into a space. Take note that due to a limitation, this space will currently be treated as an escaped char and thus will not be separated into arguments.

Internal commands

By default, bsh only recognises the following commands:

• var, create a variable with the syntax var foo somestring and print it later with @foo@
• alias, create a new command with the syntax alias foo 'some;commands' and use it later by writing foo

Single and double quotes

Text containing spaces in single or double quotes do not get separated in arguments. Additionnaly:

• Commands, variables and escape sequences (\n) are parsed between double quotes.
• Commands and variables aren't parsed at all between single quotes.
• Single quotes between double quotes are taken as normal characters, and vice-versa.
• If single quotes must occur between single quotes, they must be doubled ('').
• Litteral double quotes or single quotes (outside of single quoted strings) must be escaped with a backslash (\", \').

Parentheses

Commands can receive input from other commands if the latter ones are between parentheses: foo (bar) (baz) will translate into foo result of bar result of baz

Prol specific commands

Those are commands used by prol on top of bsh. The commands are:

echo string

Prints the following string.

mdladd modelname shaderid texid

Create a new model modelname using the shader shid and texture texid.
Prints: the id of the spawned model, or -1 on error.
Returns: same thing in integer format.

mdlpos mid x y z

Positions the model mid at pos x, y, z.
Returns: 0, -1 on error.

exec path/to/script

Executes the script located at path/to/script.
Returns: the result of the last command in the script, or -1 on error.

return res

Returns the integer res. This command doesn't actually quit the script.

?

Prints the return value of the previous command.

fov val

Sets the fov to val.

bind key command

Binds key to the given command. If prepended by a '+', the command is executed on each keypress, otherwise it is executed constantly while the key is pressed.
Returns: 0, -1 on error.

movefront, moveback, moveleft, moveright, moveup, movedown

Moves the player.

quit

Sends the exit signal to the program.

playerpos

Prints the player's current coordinates in x y z format.