Primary Syntax Elements

System Functions

System functions are numeric or string operations that process values and yield results within a program statement. PxPlus system functions consist of a three-character name, followed by arguments in parentheses:

Example:

and(A$,B$,err=0300)

Below is a list of some commonly used system functions, which can be applied to any Business Basic expression. For a list of all system functions, see System Functions.

ASC( )	Returns the internal numeric value of a given ASCII character.
CHG( )	Returns only the variables within the given argument that have changed since the last CHG( ).
CHR( )	Returns an ASCII character for a given numeric value.
DTE( )	Converts a date argument from Julian form to a formatted string.
FFN( )	Checks all open files for a reference to specified file name and returns the file number or -1 if the file is not open.
FIB( )	Returns the file information block descriptor for the file specified.
FID( )	Returns the file information descriptor for the file specified.
FIN( )	Returns detailed physical aspects of the file specified.
JUL( )	Converts a date argument from year, month, day values to Julian form; this defaults to the current date if no value is supplied.
NOT( )	Returns the inverted value of a string or numeric (i.e. with all ON bits turned OFF and vice versa).
NUL( )	Tests argument and returns either 1 (true) or 0 (false) code for null string.
NUM( )	Converts a string containing numeric characters into a corresponding real numeric value (e.g. num("1.34") yields 1.34).
PTH( )	Returns the absolute pathname for a given channel or logical file number.
STK( )	Returns the line number/program name executing at the level specified.
STR( )	Converts a numeric (or string) argument into a formatted string using an optional masking argument (e.g. str(5*6:"000") yields "030").
TCB( )	Returns value regarding task information, activation/licensing the operating system.

Examples

The PRINT directive (or ? shortcut) displays system function results:

print asc ("A")
65

print chr (65)
A

N=num("65");
print N+1
66

STR$="HELLO "+str(N);
print STR$
HELLO 65

? dte(0)
11/20/08

DATE$=dte(0:"%Dl %Ml %D/%Y");
print DATE$
Thursday November 20/2008

?jul(day)
14203
DATE$=dte(jul(day):"%Y/%M/%D");
print DATE$
2008/11/20

Code sample using NUL( ) and NOT( ):

0010 input "ENTER YOUR NAME: ",N$
0020 if nul(N$) then print "YOUR NAME IS REQUIRED!"; goto 0010
0040 input "ADDRESS: ",A$
0050 if not(nul(A$)) then goto DONE else print "ADDRESS PLEASE!"; goto 0040
0060 DONE: print "BYE"
run
ENTER YOUR NAME:
YOUR NAME IS REQUIRED!
ENTER YOUR NAME: Anthony
ADDRESS:
ADDRESS PLEASE!
ADDRESS: 45B West Wilmot Avenue
BYE

Code sample using CHG( ):

print chg("X,Y,A$,B$")
X=666
A$="HELLO WORLD"
print chg("X,Y,A$,B$")
run
X,A$

Code sample using FFN( ):

0010 let X=ffn(".") ! FFN returns channel number if the file is open
0020 if X=-1 then let X=hfn; open (X)"."! If -1 then file is not open
0030 read record (X,end=DONE)R$
0040 print R$; goto 0030
0050 DONE: print "ALL DONE, BYE-BYE!"
0060 end run
libeay32.dll
libharu.dll
license.txt
~snip~
pvxzlib1.dll
ssleay32.dll
windx
xerces-c_2_8.dll
ALL DONE, BYE-BYE!

Code sample using FIN( ):

GET_FILE_INFO:
     FILE$="."
     open (1)FILE$;
     X$=fin(1)
     TIME_STAMP$=X$(5,4),T=dec($00$+TIME_STAMP$),D=int(T/86400),T=T-D*86400
     SV_BY=prm('BY');
     set_param 'BY'=1970;
     TIME_STAMP$=" on "+dte(D,T/3600:"%Ws, %Ms %D %Yl at %hz:%mz:%sz");
     set_param 'BY'=SV_BY
     print FILE$+" last modified: "+TIME_STAMP$
     close (1)
     run
     last modified: on Thu, Oct 9 2008 at 08:36:36