PROCEDURE half5ine
 ODIM FORMULA,CALCULATE,POSITION:REAL
 OSHELL "DISPLAY 0C"
 OFORMULA=CPI+2)/15
 OCALCULATE=FORMULA
 OSHELL "TMODE -PAUSE"
 OFOR T=0 TO 100
 OCALCULATE=CALCULATE+FORMULA
 OPOSITION=INTCSINCCALCULATE)*10+16)
 OIF SGNCSINCCALCULATE))>0 THEN
 OPRINT TAHCPOSITION); "*"
 OENDI F
 ONEXT T
 OSHELL "TMODE PAUSE"
 REND

 11-151
 BASIC09 Reference
SHELL Forks another shell


Function: Executes OS-9 commands or programs from within a BASIC09 procedure. Using SHELL, you can access OS-9 functions, including multiprogramming, utilities, commands, terminal and input/output control, and so on.

 When you use the SHELL command, OS-9 creates a new process to handle the commands you provide. If you specify an operation, BASIC09 evaluates the expression and passes it to the shell for execution. If you do not specify an operation, BASIC09 temporarily halts, and the shell process displays prompts and accepts commands in the normal manner. In this case, press CTRL BREAK to return to BASIC09.

 When the shell process terminates, BASIC09 becomes active and resumes execution at the statement following the SHELL statement.

 Parameters:
string Any OS-9 command or function. String con
 stants must be enclosed in quotation marks.
 Concatenate string constants and string vari
 ables using a plus symbol (+ ).
 variable Any string variable containing an OS-9 com
 mand or function.

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Examples:
 SHELL "COPY FILE1 FILE2"

 SHELL "COPY FILE1 FILE2&"

 SHELL "COPY "+FILE$+" "+DIRNAME+"/"FILE$

 SHELL "LIST DOCUMENT"

 SHELL "KILL "+STR$CN)

 Sample Program:
You must use this procedure with the GET sample program. Using the two programs together enables you to copy all the files from one directory to another directory. The GET sample program reads the files in a directory and stores them in a file named Dirfile. This procedure reads the filenames from Dirfile and uses SHELL to copy them to the directory you specify.

 PROCEDURE copyutil
 ODIM PATH,T,COUNT:INTEGER; FILE,JOB,DIRNAME:STRING
 DOPEN #PATH , "d i r f i 1 e" :READ
 OINPUT "Name of new directory...",DIRNAME
 OSHELL "MAKDIR "+DIRNAME
 OSHELL "LOAD COPY"
 OWHILE NOTCEOFC#PATH)) DO
 OREAD *PATH,FILE
 OJOB-FILE+" "+DIRNAME+"/"+FI,LE
 DON ERROR GOTO 10
 OPRINT "COPY "; JOB
 OSHELL "COPY "+JOB
 1000N ERROR
 OENDWHILE
 OCLOSE #PATH
 REND
BASIC09 Reference
SIN Returns the sine of a number
Syntax: SIN(n um ber)
Function: Calculates the trigonometric sine of number. You can use the DEG or RAD commands to cause number to represent a value in either degrees or radians. Unless you specify DEG, the default is radians. SIN returns a real number.

 Parameters:


Examples:
PRINT SIN(4S)

 Sample Program:
This procedure calculates sine, cosine, and tangent values for a number you type.

 PROCEDURE ratiocalc pDEG ODIM ANGLE:REAL DINPUT "Enter the angle of two sides of a triangle...",ANGLE OPRINT OPRINT "Angle", "SINE", "COS I NEI' _IITANII
 OPRINT 11------------_-----------------------------

 -------------

 OPRINT ANGLE,SIN(ANGLE),COS(ANGLE).,TAN(ANGLE) OPRINT REND

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SIZE Returns the size of a data structure
Syntax: SIZE(variable)

Function: Returns the size in bytes of a variable, array, or data structure. SIZE is especially useful with random access files to determine the size of records to store in a file. You can also use SIZE to determine the size of variable storage for other purposes.


SIZE returns the size of assigned storage, not necessarily the size of a string. For example, if you dimension a variable for 15 characters, and assign a 10-character string to it, SIZE returns 15, not 10. SIZE returns the total size of arrays. That is, it returns the number of elements multiplied by the size of the elements.


Parameters:
 variable The variable, array, or data structure for
 which you want to find the size.
 Examples:
RECORDLENGTH = SIZE(A$)

 PRINT "YOUR NAME IS STORED IN A "; SIZE(NAME$); " CHARACTER STRING."

 Sample Program:

This procedure creates a simple inventory, stored in a file named Inventory. It uses SIZE to calculate the size of each element to be stored in the file, and to move the pointer to the beginning of each record's storage space.



BASIC09 Reference
PROCEDURE inventory
 pTYPE INV-ITEM=NAME:STRING125J; LIST,COST:REAL;
 QTY: INTEGER
 OD I M I NV-ARRAY( 1 0 0) : I NV-I TEM
 OD I M WORK-REC : I NV-ITEM
 ODIM PATH:BYTE
 DON ERROR GOTO 10
 ODELETE "inventory"
 1000N ERROR
 OCREATE #PATH,"inventory"
 OWORK-REC. NAME="
 OWORK-REC. L I ST= 0
 OWORK-REC. COST= 0
 OWORK-REC. QTY=0
 OFOR N=1 TO 100
 OPUT `PATH,WORK-REC
 ONEXT N
 OLOOP
 DINPUT "Record number? ",recnum
 OIF recnum<1 OR recnum>100 THEN
 OPRINT
 OPR I NT "End of Session"
 OPRINT
 OCLOSE #PATH
 REND
 DENDIF
 OINPUT "Item name? ",WORK-REC.NAME
 DINPUT "List price? ",WORK-REC.LIST
 OINPUT "Cost price? ",WORK-REC.COST
 OINPUT "Quantity? ",WORK-REC.QTY
 OSEEK #PATH,(recnum-1)*SIZE(WORK-REC)
 OPUT #PATH,WORK-REC
 OENDLOOP
 REND

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                BASIC09 Command Reference l 11


      SQ Returns the value of a number raised to the power of 2


      Syntax: SQ(number)


Function: Calculates the value of a number raised to the power of 2.

 Parameters:
 number The number you want raised to the power of 2.

 Examples:

 PRINT SQC188)

 PRINT PI·SQ(R)

 Sample Program:

 This procedure uses SQ in a formula that positions asterisks on the screen in a sine wave pattern.

 PROCEDURE 5inedown
 DIM FORMULA,CALCULATE,POSITION:REAL
 pSHELL "DISPLAY 0C"
 FORMULA=CPI+2)/1 S
 CALCULATE=FORMULA
 SHELL "TMODE -PAUSE"
 pFOR T=0 TO 200
 pCALCULATE=CALCULATE+SQCFORMULA)
 POSITION=INTCSINCCALCULATE)*12+16) OPRINT TAHCPOSITION); "*"
 NEXT T
 SHELL "TMODE PAUSE"
 REND

 11-1s7
 BASIC09 Reference
SQR/SQRT Returns the square root of a
              number


Syntax: SQR(number)
        SQRT(n um ber)


Function: Calculates the square root of a number. SQR and SQRT serve the same function.

 Parameters:
          number The number for which you want the square root.


Examples:
PRINT SQR(188)

 PRINT PI*SQRT(R)

 Sample Program:
This procedure uses SQRT in a formula to position asterisks on the screen in a sine wave pattern.

 PROCEDURE sqrdown
 ODIM FORMULA,CALCULATE,POSITION:REAL
 OSHELL "DISPLAY 0C"
 DFORMULA-P I / 1 5
 OCALCULATE-FORMULA
 OSHELL "TMODE -PAUSE"
 OFOR T=0 TO 200
 OCALCULATE-CALCULATE+SQRT(FORMULA).
 pPOSITION-INT(SIN(CALCULATE)*12+16)
 OPRINT TAH(POSITION); "*"
 ONEXT T
 pSHELL "TMODE PAUSE"
 pEND

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        BASIC09 Command Reference / 11


        STEP Establishes the size of increments in a FOR loop


Syntax:
 FOR variable = init val TO end val [STEP value] [procedure statements] NEXT variable

Function: STEP provides an increment value in a FOR/NEXT loop. If you do not specify a STEP value, the loop steps in increments of 1.


BASIC09 executes the lines following the FOR statement until it encounters a NEXT statement. Then it either increases or decreases the initial value by 1 (the default) or by the value given by STEP. If you give the loop an initial value that is greater than the final value, and specify a negative value for STEP, the loop decreases from the initial value to the end

value.
 Parameters:
 variable Any legal numeric variable name.
 init val Any numeric constant or variable.
 end val Any numeric constant or variable.
 value Any numeric constant or variable.
 procedure Procedure lines you want to be executed
 statements within the loop.

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 BASIC09 Reference
Examples:
FOR COUNTER = 1 to 100 STEP .S PRINT COUNTER NEXT COUNTER

 FOR X = 1 0 TO 1 STEP -1
 PRINT X
 NEXT X

 FOR TEST = A TO B STEP RATE PRINT TEST NEXT TEST

 Sample Program:
This procedure reverses the order of characters in a word or phrase you type. It uses STEP to decrement a counter that points to each character in the string in reverse order.

 PROCEDURE reverse pDIM PHRASE:STRING; T,BEGIN:INTEGER pPRINT "Type a word or phrase you want to reverse:"; OPRINT OINPUT PHRASE OBEGIN=LENCPHRASE) OPRINT "This is how your phrase looks backwards:" OFOR T=BEGIN TO 1 STEP -1 OPRINT MID$CPHRASE,T,1); ONEXT T OPRINT REND

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 BASIC09 Command Reference l 11
STOP Terminates a procedure
Syntax: STOP ["string"]
Function: Causes a procedure to cease execution, print the message "STOP Encountered", and return control to BASIC09's command mode. You can also specify additional text to display when BASIC09 encounters STOP.

 Use stop when you want a procedure to terminate without entering the DEBUG mode.

 Parameters:
string Text to display when STOP executes.

 Examples:
STOP "Program terminated b

 fore completion."

 IF RESPONSE = "Y" THEN STOP "Program terminated at your request." ENDIF
 BASIC09 Reference
STR$ Converts numeric data to string data Syntax: STR$(numbex)
Function: Converts a numeric type to a string type. This lets you display the number as a string or use string operators on a number. The conversion replaces the numeric values with the ASCII characters of the number. STR$ is the inverse of the VAL function.

 Parameters:
 number Any numeric-type data.

 Examples:
PRINT STRt(1010)

 DIM I:INTEGER
 I=44
 PRINT STRtCI)

 DIM H:HYTE
 H=001
 PRINT STRt(H)

 DIM R:REAL
 R=1234.56
 PRINT STRi(R)

 Sample Program:

 This procedure calculates an exponential value, then adds the necessary number of zeroes to convert it to standard notation. It uses STR$ to convert the number you type to a string type value so that it can use string functions to add the zeroes.

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 BASIC09 Command Reference / 11
PROCEDURE bignum ODIM C,PLACES,H,SIGN:STRING; EX,COUNT,NEWCOUNT, DECIMAL: INTEGER ODIM NEW,ZERO,NEWEST:STRINGL100J OCOUNT=-1 OZERO="000000000000000000000000000000000000" ONEW="" NEWEST="" OINPUT "What number do you want to raise to the power of 14?...", NUM DA=NUM"14 OH=STR$(A) OEX=SUHSTR("E",H) OSIGN=MID$(H,EX+1 ,1 ) OPLACES=RIGHT$(H,LEN(H)-EX-1) OFOR T=1 TO LEN(H) OC=MID$(H,T, 1 ) OIF C="." THEN ODECIMAL=0 OGOTO 1 0 REND I F ODECIMAL=DECIMAL+1 OIF C="E" THEN 100 ONEW=NEW+C 10ONEXT T 100ONEWCOUNT=VALCPLACES)-DECIMAL ONEW=NEW+LEFT$(ZERO,NEWCOUNT+1) OFOR T=LEN(NEW) TO 1 STEP -1 OCOUNT=COUNT+1 ONEWEST=MID$(NEW,T,1)+NEWEST OIF MOD(COUNT,3)=2 AND T),1 THEN ONEWEST=","+NEWEST REND I F ONEXT T OPRINT NUM; " to the power of 14 = "; a OPRINT "_ "; NEWEST REND

 11-163
 BASIC09 Reference
            SUBSTR Searches for specified characters in a string


Syntax: SUBSTR(targetstringsearchstring)

Function: Searches for the first occurrence of targetstring within searchstring and returns the numeric value of its location. SUBSTR counts the first character in searchstring as character Number 1. Therefore, if you searched for the string "worth" in the string "Fortworth", SUBSTR returns a value of 5.


If SUBSTR cannot find targetstring, it returns a value of 0.

 Parameters:
targetstring The group of characters you want to locate.

          searchstring The string in which you want to find targetstring.


Examples:
PRINT SUBSTR("THREE","ONETWOTHREEFOURFIVESIX")

 X=SUBSTR(" ",FULLNAME$)

 Sample Program:

This procedure selects the last name from a string containing both a first name and a last name. It uses SUBSTR to find the space between the two names in order to determine where the last name begins.


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              BASIC09 Command Reference l 11


PROCEDURE la5tname
 pDIM NAMES:STRING; LASTNAME:STRINGL101
 pPRINT "Here are the last names:"
 pFOR T=1 TO 1 0
 DREAD NAMES
 OPOINTER=SUHSTRC" ",NAMES)
 OPOINTER=LENCNAMES)-POINTER
 pLASTNAME=RIGHT$tNAMES,POINTER)
 OPRINT LASTNAME
 ONEXT T
 ODATA "Joe Blonski","Mike Marvel","Hal
 Skeemish","Fred Laungly"
 ODATA "Jane Misty","Wendy Paston","Martha
 Up5hong","Jacqueline Rivers"
 ODATA "Su5y Reetmore","Wilson Creding"
 REND

 11-165
 BASIC09 Reference
SYSCALL Executes an OS-9 System Call
Syntax: SYSCALL callcode registers

Function: Lets you execute any OS-9 system call from BASIC09. Use this command to directly manipulate your system or data or to directly access devices.


Be careful! Used improperly, SYSCALL can cause undesirable results you might unintentionally format a disk or destroy disk or memory data. Before using SYSCALL, you should be familiar with assembly language programming and should understand the system call information in the OS-9 Technical Reference manual. The OS-9 Technical Reference manual provides information about all OS-9 system calls.


To pass required register values to the SYSCALL command, create a complex data structure that contains values for all registers. Fbr example:


    TYPE REGISTERS=CC,A,B,DP:HYTE; X,Y,U:INTEGER DIM REGS:REGISTERS DIM CALLCODE:BYTE


The complex data type REGISTERS contains values for all registers. Unless you specifically assign values to variables (for instance, REGS.CC, REGS.A, and REGS.B in the previous example), they contain random values. See the TYPE command for further information.


Parameters:
callcode is the request code of the system call you wish
 to use. All system call codes are referenced in
 the OS-9 Technical Reference manual.
 registers is a list of the register entry values required
 for the system call you are using.

 Examples: see "Sample Programs."
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        BASIC 09 Command Reference / 11


Sample Programs:

The following programs set up a data type (REGISTERS) for the register variables. Before executing SYSCALL, the procedures store the required register entry values in the complex data structure REGS. The procedures also establish CALLCODE as a variable to hold the request code of the system call you want to use.


The Writecall procedure uses the string variable TEST to store text that it writes to the screen through Path 0 (the standard output path) using System Call $8A, I$Write. Before the procedure calls I$Write, it stores the appropriate path number (0) in Register A. The ADDR command calculates the address of the variable TEST, and the LEN command determines the length of the variable. The procedure stores these two values in Registers X and Y.


The Readcall uses System Call $8B, I$ReadLn to perform a function that is the opposite of Writecall. Readcall establishes TEST as a string variable into which it writes the characters you type. Because the length of TEST is restricted to ten characters (DIM TEST: STRING[ 1 0 1 ), the terminal bell sounds if you attempt to type more than 10 characters. Pressing [ENTER] terminates the call and the procedure prints the contents of TEST the characters you typed.


11-167
 BASIC09 Reference
PROCEDURE WriteCall
 OTYPE REGISTERS=CC,A,B,DP:BYTE; X,Y,U:INTEGER
 ODIM REGS:REGISTERS
 ODIM PATH,CALLCODE:BYTE
 ODIM TEST:STRINGL50l
 OTEST="This is a test of I$Write,,Sy5tem call
 $8A..."
 OREGS.A=0
 OREGS.X=ADDRCTEST)
 OREGS.Y=LENCTEST)
 OCALLCODE=$8A
 ORUN SYSCALLCCALLCODE,REGS)
 OPRINT
 REND

 PROCEDURE Readcall
 OTYPE REGISTERS=CC,A,B,DP:BYTE; X,Y,U:INTEGER
 ODIM REGS:REGISTERS
 ODIM PATH,CALLCODE:BYTE
 ODIM TEST:STRINGf10l
 OREGS.A=0
 OREGS.X=ADDRCTEST)
 DREGS . Y=1 0
 OCALLCODE=$8B
 ORUN SYSCALLCCALLCODE,REGS)
 OPRINT
 OPRINT TEST
 REND

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 BASIC09 Command Reference l 11
      TAB Causes PRINT to jump to the specified column


      Syntax: TAB(number)


Function: Causes PRINT to display the next PRINT item to display in the column specified by number. If the cursor is already past the desired tab position, BASIC09 ignores TAB.


Use POS to determine the current cursor position when displaying characters on the screen.


Screen display columns are numbered from 1, the leftmost column, to a maximum of 255. The size of BASIC09 output buffer varies according to the stack size.


You can also use TAB with PRINT USING statements.

 ,^ Parameters:
        number The column at which you want PRINT to begin.


Examples:
PRINT TAB(20);TITLE$

 PRINT TAH(X);ITEMNUMBER;ITEM$

 Sample Program:

This procedure uses asterisks to simulate a sine wave on the screen. It uses TAB to position each asterisk in the proper location.


11469
 BASIC09 Reference
PROCEDURE 5inewave
 pDIM FORMULA,CALCULATE,POSITION:REAL
 OSHELL "DISPLAY 0C"
 OFORMULA=CPI+2)/1 S
 OCALCULATE=FORMULA
 OSHELL "TMODE -PAUSE"
 OFOR T=0 TO 200
 OCALCULATE=CALCULATE+SQCFORMULA)
 OPOSITION=INTCSINCCALCULATE)*12+16)
 OPRINT TAHCPOSITION); "*"
 ONEXT T
 OSHELL "TMODE PAUSE"
 REND

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 BASIC09 Command Reference l 11
TAN Returns the tangent of a value
Syntax: TAN(n um ber)
Function: Calculates the trigonometric tangent of number. Using DEG or RAD, you can specify the measure of the angle (number) in either degrees or radians. Radians are the default units.

 Parameters:
number The angle for which you want to find the
 tangent.

 Examples:
PRINT TANC45)

 Sample Program:
This procedure calculates sine, cosine, and tangent values for a number you type.

 PROCEDURE ratiocalc
 ODEG
 DIM ANGLE:REAL pINPUT "Enter the angle of two sides of a triangle...",ANGLE pPRINT pPRINT "Angle", "SINE","COSINE","TAN"

 SPRINT ANGLE,SINCANGLE),COSCANGLE),TANCANGLE)
 pPR I NT
 pEND
 BASIC09 Reference
TRIM$ Removes spaces from the end of a string

 Syntax: T RIM$(,string)

Function: Removes any trailing spaces from the end of the specified string. This function is particularly useful for trimming records you recover from a random access file.


Parameters:

          string The string or string variable from which you wish to remove trailing spaces.


Examples:

 PRINT TRIM$(A$)

 GET A$,B$,C$
 PRINT TRIM$(A$),TRIM$(B$),TRIM$(C$)

 Sample Program:

This program takes names you type and puts them in a random access disk file. Because random access files use the same amount of storage for each item, short names are pfd with extra spaces. When reading the names back from the file, the procedure uses TRIM$ to remove these extra spaces.


PROCEDURE namestor

ODIM NAMES,TEMP1,NAME(100):STRINGL261; FIRST,LAST: STRINGf15l; INITIAL:STRINGL1J

DDIM PATH,T:INTEGER
 ONAMES=""
 DON ERROR GOTO 10

FIDELETE "nameli5t" 100ON ERROR

OCREATE #PATH,"nameli5t":UPDATE OFOR T=1 TO 1 00

[INA ME (T)
 ONEXT T
 OT = 0

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 BASIC09 Command Reference l 11
pL00P
 DINPUT "First Name: ",FIRST
 DEXITIF FIRST="" THEN
 OCLOSE #PATH
 OGOTO 1 0 0
 OENDEXIT
 OINPUT "Initial: ",INITIAL
 OINPUT "Last: ",LAST
 OT=T+ 1
 ONAMECT)=FIRST+" "+INITIAL+" "+LAST
 OPUT #PATH,NAMECT)
 OSEEK #PATH,T*26
 OENDLOOP
 1000OPEN #PATH,"namelist":READ
 OPRINT \ PRINT
 OPRINT "Lastname","Firstname","Initial
 OREM Print underline C40 characters)
 OPRINT " -
 OPRINT
 OSEEK #PATH,O
 OT = 0
 OWHILE NOTCEOFC#PATH)) DO
 OGET #PATH,NAMES
 OT=T+ 1
 ONAMES=TRIM$CNAMES)
 OX=SUHSTRC" ",NAMES)
 OFIRST=LEFT$CNAMES,X-1)
 OTEMP1=RIGHT$CNAMES,LENCNAMES)-X+1)
 OINITIAL=MID$CTEMP1 ,2,1 )
 OLAST=RIGHT$CTEMP1,LENCTEMP1)-3)
 OPRINT LAST,FIRST,INITIAL
 OSEEK #PATH,T*26
 DENDWHILE
 OCLOSE #PATH
 REND

 11-173
 BASIC09 Reference
TRON/TROFF Turns on/off trace function
Syntax: TRON
        TROFF


Function: Turns on or off the BASIC09 trace mode. When trace is turned on (TRON), BASIC09 decompiles and displays each statement in a procedure before execution. BASIC09 also displays the result of each expression after evaluation. This function lets you follow program flow and is helpful in debugging and analyzing the execution of a procedure. After the procedure is debugged, remove the TRON statement.


If you want to view only a portion of a procedure's execution, surround that portion with TRON and TROFF. Tracing begins immediately after the TRON statement and ends at the TROFF statement. The rest of the program executes normally.


Parameters: None

 Examples:
H$="00000000000000000000"+H$ N=1 +LEN(H$ FOR I=4 TO 1 STEP -1 TRON N=N-4 A(I)=VAL(MID$(H$,N,4)) TROFF NEXT I

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          BASIC09 Command Reference / 11


        TRUE Returns a Boolean TRUE value tax: variable = TRUE


      Function: TRUE is a Boolean function that always returns True. You can use TRUE and FALSE to assign values to Boolean variables.


      Parameters:

      variable The Boolean storage unit you want to set to

      True.

      Examples:


        DIM TEST:HOOLEAN TEST=TRUE


      Sample Program:


      This procedure asks five questions. If your answer is correct, it stores the Boolean value TRUE in a Boolean type variable. If your answer is incorrect, .it stores the Boolean value FALSE in the variable.


        PROCEDURE quiz pDIM REPLY,VALUE:BOOLEAN; ANSWER:STRINGf1l; QUESTION:STRINGL80J pFOR T=1 TO 5 DREAD QUESTION,VALUE pPRINT QUESTION OPR I NT "CT) = TRUEE100000pCF) = FALSE" OPRINT "Select T or F:OO"; OGET x1,ANSWER OIF ANSWER="T" THEN OREPLY=TRUE

,~` DELSE
        OREPLY=FALSE

        REND I F

        OIF REPLY=VALUE THEN

        OPRINT \ PRINT "That's Correct ...Good Show!"

        DELSE


                                    11-175

BASIC09 .Reference
pPRINT "Sorry, you're wrong ...Hetter Luck next time." DENDI F OPRINT \ PRINT \ PRINT ONEXT T ODATA "In computer talk, CPU stands for Central Packaging Unit.", FALSE ODATA "The actual value of 64K is 65536 bytes.",TRUE ODATA "The bits in a byte are normally numbered 0 through 7.",TRUE ODATA "HASIC09 has four data types.",FALSE ODATA "The LAND function is a Boolean type operator.",FALSE REND

 11-176