NAME

tcbasic - a small BASIC Interpreter written in C

SYNOPSIS

tcbasic [filename]

DESCRIPTION

tcbasic implements a small subset of BASIC in portable C. If the user specifies a filename on the command line or pipes data to tcbasic, the results will be written to standard out. If no file is specified, an interactive mode is started where a user can interact with the BASIC system directly.

OPTIONS

-h, -? --help: Print a helpful message and exit
-v --version: Print version information and exit

STATEMENTS

REM remark: Remark has no effect on the execution of the program and acts as a comment to the developer. The remark can contain any character.
PRINT list: Prints the contents of 'list' to the console where 'list' is a comma separated list of one or more quoted strings, expressions, and/or variables.
IF expression relop expression THEN statement: Evaluates both 'expression's and compares them using relational operator 'relop'. If the relation is true, then the statement will be executed. Otherwise, the statement is skipped.
GOTO expression: Evaluates 'expression' and jumps to the corresponding line number.
INPUT var_list: Given a comma separated list of 1 or more variables, this command will prompt the user to enter a comma separated list of expressions. The value of each expression will be assigned to each corresponding variable.
GOSUB expression: Evaluates 'expression' and jumps to the corresponding line number after saving the current line number.
RETURN: Returns control to the line after the last 'GOSUB' call.
LET var = expression: Assigns the value of expression to variable 'var' where 'var' is a single character variable name in the range from A to Z.
END: Ends the execution of the program.
STOP: Exits the interpreter.
BEEP: System beep.
SHELL cmd: Executes a shell command.
RANDOMIZE: Re-seeds the random number generator, causing RND to return a different sequence of random numbers. CLS Clears the screen.

FUNCTIONS

RND: Returns a random number in the range [0,1). The same sequence of numbers is returned in each program run. Use the RANDOMIZE statement to generate different sequences in each program run.
TIME: Returns the number of seconds since midnight.
SIN (expression): Returns the sine of the given expression (measured in radians).
COS (expression): Returns the cosine of the given expression (measured in radians).
TAN (expression): Returns the tangent of the given expression (measured in radians).
COT (expression): Returns the cotangent of the given expression (measured in radians).
ATN (expression): Returns the arctangent of the given expression (measured in radians).
EXP (expression): Returns e to the power of the given expression.
LOG (expression): Returns the natural logarithm of of the given expression.
ABS (expression): Returns the absolute value of the given expression.
INT (expression): Returns the integer portion of the given expression.
SGN (expression): Returns the sign of the given expression. 1, 0, or -1 for positive, zero, or negative.
SQR (expression): Returns the square root of the given expression.

COMMANDS

CLEAR: Clears the program from memory and sets all variables to 0.
LIST: Prints the current program.
RENUM: Renumber lines in memory.
RUN: Executes the current program.
TROFF: Turns off debug tracing.
TRON: Turns on debug tracing.

AUTHORS

See https://github.com/tcort/tcbasic/graphs/contributors

REPORTING BUGS

See https://github.com/tcort/tcbasic/issues

COPYRIGHT

Copyright © 2015, 2016, 2017, 2018, 2020 Thomas Cort <linuxgeek@gmail.com>
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.