bob (04/19/83)
Here at UNM we have a basic (interpreter) system that was written for instructional use at a branch college. It is not complete as it doesn't have file or formatted I/O, but it is written in YACC and C (so if you really wanted to extend it...). It was written on a 4.1 bsd system and someone inside Bell (on a USG 5.x system) had some problems bringing it up. If you are interested send a tape (mini-reel is fine) and return postage (and, judging by the discussions about YACC generated grammers, a copy of your Unix license wouldn't be a bad idea). Bob Tomlinson University of New Mexico Computer Center 2701 Campus Blvd. Albuquerque, NM 87106 (505) 277-6131 ucbvax!lbl-csam!lanl-a!unm-ivax!bob purdue!lanl-a!unm-ivax!bob Here is a copy of the man page: .TH BASIC L local .SH NAME basic \- Vax Basic subsystem .SH SYNOPSIS .B basic [ -p ] [ file-name ] .SH DESCRIPTION .de P .br .ne 0.5i .sp .5 .IP "\\$1" 10 .br .. .I Vax-Basic is a truncated version of BASIC that closely resembles IBM\ VS/BASIC (don't ask why). When .I basic is started up, execution starts with a command monitor that looks over the user's workspace, which contains the BASIC program to be run. The user is prompted with a greater-than sign ``>'' for a monitor command. If the .B -p option is specified, .I basic will issue prompts, even if it's input is not a terminal. This is very useful when using .I basic with .IR script (1). .sp If .I file-name is specified on the command-line, a .I "load file-name" command is simulated before monitor prints its prompt. .sp When files are loaded into the workspace, they are converted to an internal form (trees) which can be easily executed. When the workspace is listed on the terminal, or written to a file, a printable version of this internal form is what is written. This means that some user-specified formatting may be lost. Extra parenthesization and indentation are not lost, however. .sp The following definitions will be used thoughout the description of monitor commands and basic statements: .P "line-number" Any integer between 1 and 99 999 999. .P "line-no-range" A .I line-no-range is either a line-number, two line-numbers separated by \-, or .I % (meaning all the lines in the workspace). .P "file-name" A .I file-name is a string of characters denoting a Unix file. To avoid troubles, it is a good idea to limit your choice of filenames to those containing only letters, numbers and the special characters in the string ``._+-:=''. .P "basic-stmt" A .I basic-stmt is any valid Vax-Basic statement. .P "n" A whole number. .SH MONITOR COMMANDS Monitor commands can be abbreviated to their significant prefix. Available monitor commands are: .P "\fBhelp\fR" A brief list of the most important monitor commands is printed at the terminal. .P "\fBload\fR \fIfilename\fR" The workspace is cleared, and the named file is loaded into it. The name associated with the workspace is .IR filename . .P "\fBload\fR" The workspace is cleared, and the file last saved or loaded is loaded back into the workspace. It is an error if the workspace has no name associated with it. .P "\fBsave\fR \fIfilename\fR" The workspace is saved on the named file. If the workspace has no name, it becomes .IR filename . .P "\fBsave\fR" The workspace is saved on the file associated with the workspace. .P "\fBlist\fR" The program currently in the workspace is listed on the terminal. .P "\fBlist\fR \fIline-no-range\fR" The lines in the given range are printed on the terminal. .P "\fBrun\fR" The program variables are cleared, and the program in the current workspace is executed. .P "\fBquit\fR" Leave .I basic and return to the shell. .P "\fBexit\fR" Same as .IR exit . .P "\fIline-number basic-stmt\fR" The .I basic-stmt is inserted in the workspace with the given .IR line-number . If a line with the same number already exists in the workspace, it is deleted first. .P "\fBdelete\fR \fIline-no-range\fR" The specified lines are deleted from the workspace. It is an error if the lines specified do not appear in the workspace. .P "\fIbasic-stmt\fR" If the basic statement is not a .BR for , .BR next , .BR dim , or .B data statement, it is executed immediately. It is not inserted into the workspace. .P "\fBvi\fR" Invoke the editor .I vi on the workspace, then load the result back into the workspace. This is the normal way to perform non-trivial changes on the workspace. .P "\fBedit\fR" Invoke the editor .I ex on the workspace, then load the result back into the workspace. This command is provided on the off chance you are not using a crt. .P "\fBrenumber\fR \fIline-number\fR, \fIincrement\fR" The basic statements in the workspace are renumbered. The first line in the workspace will have .I line-number as its associated line number, the second .IR line-number+increment , the third .IR line-number+2*increment , and so on. .sp .5 If .I line-number is omitted, 1000 is used. .sp .5 If .I increment is omitted, 10 is used. .P "\fBstep\fR" .I Step is like run, except that the program is run in single-step mode. The first statement is executed, the next statement to be executed is printed, and then control returns back to the monitor. To execute more statements, use the .I continue command. .P "\fBcontinue\fR \fIn\fR" In single-step mode, the next .I n statements are executed. If .I n is omitted, 1 statement is executed. .br .ne 12 .SH BASIC STATEMENTS In the description of the statements recognized by .IR basic , items in .B bold-face are .I basic symbols, ellipses (...) denote repetition, and .P "[ \fIoptional-items\fR ]" marks that .I optional-items may be omitted from the statement. .P "real-id" is the name of an arithmetic variable. Arithmetic variables begin with letters, and are followed by zero or more letters or digits. Very long identifiers are allowed. .P "integer-id" is the name of an integer variable. Integer-ids follow the same rule as real-ids, but are followed by a percent sign ``%''. .P "string-id" is the name of a string variable. String-ids follow the same rule as real-ids, but are followed by a dollar sign ``$''. .P "variable" is either a .I real-variable , an .I integer-variable or a .IR string-variable . .P "real-variable" is a real-id possibly followed by a subscript. .P "integer-variable" is an integer-id possibly followed by a subscript. .P "string-variable" is a string-id possibly followed by a subscript. .P "expr" is a valid BASIC expression. .P "real-expr" is a valid arithmetic expression. .P "string-expr" is a valid string-valued expression. .P "logical-expr" is a relational expression involving .BR = , .BR <> , .BR < , .BR <= , .BR > , .BR >= , parenthesized logical-exprs, or logical-exprs separated by .BR and s or .BR or s .P "mat-id" is the name of a matrix variable, one that appears in a .B dim statement. .sp 1.5 .in 0 The following BASIC statements are understood: .P "[ \fBlet\fR ] real-variable \fB=\fR real-expr" The arithmetic expression is evaluated and is assigned to the variable. When written out, the .B let is dropped from the statement. .P "[ \fBlet\fR ] string-variable \fB=\fR string-expr" The string expression is evaluated and is assigned to the variable. When written out, the .B let is dropped from the statement. .P "\fBend\fR" This must be the last statement in your .I basic program. When this statement is executed, the basic program halts, and the monitor resumes control again. .P "\fBstop\fR" When this statement is executed, the basic program halts, and the monitor resumes control again. .P "\fBrem\fR \fIany-text-whatsoever\fR" This statement is used to provide commentary for the program. This statement has no effect upon the execution of the program. .P "\fBinput\fR variable [ \fB,\fR variable ] ..." A question mark ``?'' is printed on the terminal, and the values of the specified variables are read from the terminal. .P "\fBmat input\fR mat-id [ \fB,\fR mat-id ] ..." A question-mark ``?'' is printed on the terminal, and values are read in from the terminal for the specified matrices. .P "\fBread\fR variable [ \fB,\fR variable ] ..." The values for the specified variables are taken from the next un-\fBread\fR values in .B data statements that appear in the program. .P "\fBmat read\fR mat-id [ \fB,\fR mat-id ] ..." The values for the specified matrices are taken from the next un-\fBread\fR values in .B data statements that appear in the program. .P "\fBdata\fR value [ \fB,\fR value ] ..." The specified data values are recorded for later use with either .B read or .B "mat read" statements. .IR Value s are either numeric or string constants. .P "\fBprint\fR expr [ \fB,\fR expr ] ..." The .IR expr s are evaluated and printed on the terminal in wide (14 character) fields. .I Basic will print subsequent output a new line. .P "\fBprint\fR expr [ \fB;\fR expr ] ... [ \fB;\fR ]" The .IR expr s are evaluated and printed on the terminal in narrow fields just wide enough to hold the expression. .br Commas (\B,\fR) and semi-colons (\fB;\fR) can both be used to separate expressions in a single .br If a semi-colon (\fB;\fR) appears by itself at the end of a .B print statement, subsequent output will be on the same output line. .P "\fBmat print\fR mat-id [ \fB,\fR mat-id ] ..." The values of the named matrices are printed in wide fields. Each row of each matrix starts on a new line, and different matrices are separated by blank lines. .P "\fBmat print\fR mat-id [ \fB;\fR mat-id ] ..." The values of the named matrices are printed in narrow fields. Each row of each matrix starts on a new line, and different matrices are separated by blank lines. .P "\fBdim\fR dim-var subscripts [ \fB,\fR dim-var subscripts ] ..." The specified dim-vars are dimensioned when this statement is executed. It is an error to dimension the same variable twice during the execution of a program. Dim-vars look like: .RS 10 .P "string-id \fIn\fR" a string variable of length .IR n . .I n must be greater than 0 and less than 256. .P "string-id" a string variable of length 32. .P "real-id" an arithmetic variable. .RE Subscripts look like .RS 10 .P "\fB[\fR \fIn\fR \fB]\fR" single-dimensioned matrix with subscripts from 1 to .IR n . .P "\fB[\fR \fIn\fR \fB,\fR \fIm\fR \fB]\fR" two-dimensional matrix with first subscript ranging from 1 to .IR n , and second subscript ranging from 1 to .IR m . .br .I n and .I m may be any arithmetic expressions. .RE .P "\fBgoto\fR line-number" Execution will proceed from the named line. An error occurs if there is no such line in the program. .P "\fBgosub\fR line-number" Like .BR goto , except that the statement following the .B gosub statement is remembered, and when a .B return statement is executed, program execution reverts to the statement following the .IR gosub . .BR gosub s can be nested up to 100 levels deep. .P "\fBreturn\fR" See .BR gosub . .P "\fBif\fR logical-expr \fBthen\fR basic-stmt [ \fBelse\fR basic-stmt ]" The logical-expr is evaluated, and if the value is true, the basic-stmt following the .B then is executed. If the value of the logical-expr is false, and there is a basic-stmt following .BR else , that statement is executed. If the value of the logical-expr is false, and there is no .B else part, nothing else happens. .P "\fBfor\fR real-id \fB=\fR real-expr \fBto\fR real-expr [ \fBstep\fR real-expr ]" The value of the real-expr following the .B = is evaluated and assigned to the real-id. If the step-value (the value of the real-expr following .I step if it exists, otherwise 1) is greater than 0 (less than 0) and the value of the real-id is less than or equal to (greater than or equal to) the value of the expression following .BR to , execution continues with the following statement. Otherwise, execution skips to the statement following the next .I next statement with the same real-id. .P "\fBnext\fR real-id" The step-value of the current .B for statement is added to the corresponding real-id, and if the value of the real-id is less than or equal to (greater than or equal to if the step-value is negative) the corresponding .B to value, execution reverts to the statement following the .B for statement. Otherwise execution resumes with the statement following the .BR next . .ne 5 .sp 2 .in 0 In the following descriptions of .B mat statements, all matrices must be arithmetic. .in 0 .sp 1 .P "\fBmat\fR mat-id \fB=\fR mat-id" Matrix assignment. The values in the second mat-id are assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. .P "\fBmat\fR mat-id \fB= -\fR mat-id" Matrix negation. The values in the second mat-id are negated and assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. .P "\fBmat\fR mat-id \fB=\fR mat-id \fB+\fR mat-id" Matrix addition. The values in the second mat-id are added to the values of the third, and assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. .P "\fBmat\fR mat-id \fB=\fR mat-id \fB-\fR mat-id" Matrix subtraction. The values in the third mat-id are subtracted from the values of the second, and assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. .P "\fBmat\fR mat-id \fB=\fR mat-id \fB*\fR mat-id" Matrix multiplication. The second and third matrices are multipled together and assigned to the first. If the second matrix is dimensioned [l,m] and the third [m,n], the first must be dimensioned [l,n]. .P "\fBmat\fR mat-id \fB= idn\fR" The matrix is assigned an identity matrix. The matrix must be square. .P "\fBmat\fR mat-id \fB= zer\fR" The matrix is zeroed. .P "\fBmat\fR mat-id \fB= rnd\fR" The matrix is assigned all random elements. .P "\fBmat\fR mat-id \fB= inv(\fRmat-id\fB)\fR" Matrix inverse. The first matrix is assigned the matrix inverse of the second. Both matrixes must be square, and have the same rank. .P "\fBmat\fR mat-id \fB= trn(\fRmat-id\fB)\fR" Matrix transposition. The first matrix is assigned the transpose of the second. If the second is dimensioned [m,n], the first matrix must be dimensioned [n,m]. .P "\fBmat\fR mat-id \fB=\fR \fB(\fRreal-expr\fB)\fR" Scalar assignment to a matrix. The real-expr is evaluated, and assigned to all the elements of the matrix. .P "\fBmat\fR mat-id \fB=\fR \fB(\fRreal-expr\fB) +\fR mat-id" Scalar addition. The value of the arithmetic expression is added to the elements of the second matrix and assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. .P "\fBmat\fR mat-id \fB=\fR \fB(\fRreal-expr\fB) -\fR mat-id" Scalar subtraction. The elements of the second matrix are subtracted from the value of the real-expr and assigned to the first matrix. The mat-ids must have the same number of dimensions, .P "\fBmat\fR mat-id \fB=\fR function \fB(\fRmat-id\fB)\fR" Scalar function application. The named function is applied to each element of the second matrix and assigned to the first. The mat-ids must have the same number of dimensions, with the same number of elements in each dimension. See FUNCTIONS for a list of arithmetic functions. .br .ne 12 .SH EXAMPLE BASIC SESSION In the following example session, computer output is in italics. .nf .sp \fI%\fR basic \fI>\fR 100 data 1,2,3,4,5,6,7,8,9 \fI>\fR 110 dim a[3,3] \fI>\fR 120 mat read a \fI>\fR 130 mat a = inv(a) \fI>\fR 140 mat print a \fI>\fR run \fIError, line 130: Can't invert matrix 'a': it is singular.\fR \fI4 statements executed\fR \fI>\fR edit "/tmp/Bas005217" 5 lines, 110 characters \fI:\fR 1s/9/0/p \fI100 data 1, 2, 3, 4, 5, 6, 7, 8, 0\fR \fI:\fR w \fI"/tmp/Bas005217" 5 lines, 110 characters\fR \fI:\fR q \fI>\fR run \fI-1.77778 0.888889 -0.111111 1.55556 -0.777778 0.222222 -0.111111 0.222222 -0.111111 5 statements executed\fR \fI>\fR save matrix.b "matrix.b", 5 lines \fI>\fR q 0.53 cpu secs used, 32+22k memory, 31+31 page faults. .fi .br .ne 12 .SH FUNCTIONS This section lists all the available intrinsic functions for .IR basic . In the following descriptions, .IR x , .IR y , and .I z denote arithmetic expressions, and .I s denotes a string expression. .P "\fBabs\fR(x)" returns the absolute value of x. .P "\fBacs\fR(x)" returns the arc-cosine of x. .P "\fBasn\fR(x)" returns the arc-sin of x. .P "\fBatn\fR(x)" returns the arc-cosine of x. .P "\fBchr\fR(x)" returns a character string formed by converting the value of x to a string. .P "\fBcos\fR(x)" returns the cosine of x radians. .P "\fBcot\fR(x)" returns the cotangent of x radians. .P "\fBcpu\fR" returns the number of cpu seconds taken by program execution. .P "\fBcsc\fR(x)" returns the cosecant of x radians. .P "\fBdeg\fR(x)" returns the number of degrees in x radians. .P "\fBdet\fR(mat-id)" returns the determinant of the given matrix. Note that even though the determinant may be non-zero, it may still be invalid to take the inverse. .P "\fBexp\fR(x)" natural exponentiation of x. .P "\fBhcs\fR(x)" returns the hyperbolic cosine of x. .P "\fBhsn\fR(x)" returns the hyperbolic sine of x. .P "\fBhtn\fR(x)" returns the hyperbolic tangent of x. .P "\fBint\fR(x)" returns the integer part of x. .P "\fBlen\fR(s)" returns the number of characters in s. .P "\fBlgt\fR(x)" returns the logarithm of x to the base 10. .P "\fBlog\fR(x)" returns the natural logarithm of x. .P "\fBltw\fR(x)" returns the logarithm of x to the base 2. .P "\fBmax\fR(x,y)" returns the maximum of x and y. .P "\fBmin\fR(x,y)" returns the minimum of x and y. .P "\fBnum\fR(s)" returns the numeric value of the string s. .P "\fBrad\fR(x)" returns the number of radians in x degrees. .P "\fBrnd\fR" returns a random number between 0 and 1 exclusive. .P "\fBrnd\fR(x)" sets the random-number seed to x, and then returns a random number between 0 and 1 exclusive. .P "\fBsec\fR(x)" returns the secant of x radians. .P "\fBsgn\fR(x)" returns the sign of x: -1 if x < 0, 0 if x = 0, +1 if x > 0. .P "\fBsin\fR(x)" returns the sine of x radians. .P "\fBsqr\fR(x)" returns the square root of x. .P "\fBstr\fR(s, x, y)" returns the substring of s that begins with character number x (starting from 1), and proceeds for y characters. .P "\fBstr\fR(s, x)" returns the substring of s that begins with character number x (starting from 1) to the end of s. .P "\fBtan\fR(x)" returns the tangent of x radians. .P "\fBtim\fR" returns the time of day in seconds from midnight. .SH FILES .ta 15n +10n +10n +10n /tmp/Basnnnnn Basic temporary files during \fIedit\fR or \fIvi\fR. .SH SEE ALSO .I "IBM VS BASIC Language" (GC28-8303-2). .SH BUGS Some people do not like the fact that .I basic reformats their programs. .sp .B "print using" is not implemented yet. .sp File input/output is not implemented yet. .sp .5 Blanks are significant, and are used to delimit names. .B "rem ark" and .B "remark" are not the same things. .B remark does not begin a .B rem statement.
brent (04/21/83)
Yes, the British Columbia guys (Bill Webb) do have a BASIC for Unix. I
believe that he has ported it to another Vax on campus running 4.1BSD
(we don't have it on this machine) You can get in touch with Bill by
mailing to "...!{microsoft,uw-beaver}!ubc-vision!webb" (This was posted
'cause I don't think he reads the news)
Dave Brent
University of British Columbia
Laboratory for Computational Visionbrent (04/21/83)
Um, parsec!kolstad's article was posted "Sun, 24-Apr-83 00:36:56 EST" and yet we received it "Tue Apr 19 02:40:10 1983"!! And people want to increase the efficiency of UUCP?!? :-)