Extended BASIC Commands

base 0|1

Specifies the starting index for arrays.

chain stringexp

Reads in a BASIC script from file stringexp and starts to execute it.

close exp

Closes a file whose file number is exp. Releases the file descriptor and flushes all stored data.

def fnname { (var1 {,var2...varn} ) } = exp

Defines the user-defined function fnname, which evaluates the expression exp and returns the result. var1...varn are optional dummy arguments whose values can be used in evaluating exp.

error exp

Executes the given error sequence.

input #f list

Inputs data from file f into list, a comma-separated list of variable names.

input list

Inputs data from a terminal into #list, a comma-separated list of variable names.

linput {#f} a$

Inputs data from a terminal (or optionally from file number f) into the string a$. This command is identical to the input command except that it ignores separators and treats the input line as a single string.

random

Randomizes the random number generator.

repeat

Specifies the start of a repeat-until loop.

resume {l}

Returns from an error trap set by an on error goto statement. If l is specified, goes to that line number.

on error goto l

If an error occurs, transfers control to line number l.

on exp gosub l1 {,l2...ln}

Evaluates the expression exp and transfers control to the subroutine defined at one of the line numbers in the l1...ln list.

on exp goto l1 {,l2,...ln}

Evaluates the expression exp and, based on the results, transfers control to one of the line numbers in the l1...ln list. If exp=1, control transfers to l1, and so forth.

open stringexp {for input|output|append} as exp

Opens the file stringexp for reading, writing, or updating. Assigns the file number exp to the file.

until exp

Defines a repeat-until loop. Execution of the loop repeats until exp becomes false.

while exp

Specifies the start of a while loop. Execution of the loop repeats until exp is false.

wend

Terminates the block of statements contained in a while loop.