FT_AT2() Find position of the nth occurrence of a substring FT_BITCLR() Clear (reset) selected bit in a byte FT_BITSET() Set selected bit in a byte FT_BYTEAND() Perform bit-wise AND on two ASCII characters (bytes) FT_BYTENEG() Perform bit-wise negation on an ASCII character FT_BYTENOT() Perform bit-wise NOT on an ASCII character (byte) FT_BYTEOR() Perform bit-wise OR on two ASCII characters (bytes) FT_BYTEXOR() Perform bit-wise XOR on two ASCII characters (bytes) FT_FINDITH() Find the "ith" occurrence of a substring within a string FT_ISBIT() Test the status of an individual bit FT_ISBITON() Determine the state of individual bits in a number FT_METAPH() Convert a character string to MetaPhone format FT_NOOCCUR() Find the number of times one string occurs in another FT_PCHR() Convert printer control codes FT_PROPER() Convert a string to proper-name case
Tag Archives: FT_BITSET()
FT_ISBITON
FT_ISBITON()
Determine the state of individual bits in a number
Syntax
FT_ISBITON( <nNumber>, <nBit> ) -> lResult
Arguments
<nNumber> is an integer for which a bit state needs to be checked.
<nBit> is a number from 0 to 15 that indicates which bit to test.
Returns
.T. if the specified bit was on., .F. if off.
Description
This function is useful when dealing with binary integers. It will
come in very handy if you use the FT_INT86() function, because the
CPU flags are returned as a series of bits. Using this function, you
can determine the state of each CPU flag.
Examples
if FT_ISBITON( nCPUFlags, 0 )
Qout( "The carry flag was set." )
endif
if FT_ISBITON( nCPUFlags, 7 )
Qout( "The sign flag was set." )
endif
Source: ISBITON.PRG
Author: Ted Means
FT_ISBIT
FT_ISBIT()
Test the status of an individual bit
Syntax
FT_ISBIT( <cByte>, <nBitPos> ) -> lResult
Arguments
<cByte> is a character from CHR(0) to CHR(255)
<nBitPos> is a number from 0 to 7 conforming to standard right-to-left
bit-numbering convention and representing the position of the
bit within the byte.
Returns
.T. if designated bit is set (1), .F. if not set (0), NIL if
invalid parameters.
Description
Tests for status of any selected bit in the byte passed as a parameter.
Byte must be presented in CHR() form, as a literal constant, or as the
one-byte character result of an expression.
This function is presented to illustrate that bit-wise operations
are possible with Clipper code. For greater speed, write .C or
.ASM versions and use the Clipper Extend system.
Examples
This code tests whether bit 3 is set in the byte represented by
CHR(107):
lBitflag := FT_ISBIT(CHR(107), 3)
? lBitflag // result: .T.
This code tests whether bit 5 is set in the byte represented by ASCII
65 (letter 'A')
? FT_ISBIT('A', 5) // result: .F.
For a demonstration of Clipper bit manipulations, compile and
link the program BITTEST.PRG in the Nanforum Toolkit source code.
Source: ISBIT.PRG
Author: Forest Belt, Computer Diagnostic Services, Inc.
See Also: FT_BITSET() FT_BITCLR()
FT_BITSET
FT_BITSET()
Set selected bit in a byte
Syntax
FT_BITSET( <cByte>, <nBitPos> ) -> cByte
Arguments
<cByte> is a character from CHR(0) to CHR(255).
<nBitPos> is a number from 0 to 7 conforming to standard right-to-left
bit numbering convention and representing the position of the bit
within the byte.
Returns
Returns new byte, with designated bit set. If parameters are faulty,
returns NIL.
Description
In effect, ORs argument byte with a byte that has only the target bit
set. If bit is already set, it remains set.
Note: Calls FT_ISBIT() which is also in this Library.
This function is presented to illustrate that bit-wise operations
are possible with Clipper code. For greater speed, write .C or
.ASM versions and use the Clipper Extend system.
Examples
This code would set bit 4 in a byte represented by CHR(107):
cNewbyte := FT_BITSET( CHR(107), 4 )
? ASC( cNewbyte ) // result: 123
? cNewbyte // result: '{'
This code would set bit 5 in the byte represented by the letter 'A'.
? FT_BITSET( 'A', 5 ) // result: 'a'
// bit 5 set
For a demonstration of Clipper bit manipulations, compile and
link the program BITTEST.PRG in the Nanforum Toolkit source code.
Source: BITSET.PRG
Author: Forest Belt, Computer Diagnostic Services, Inc.
See Also: FT_BITCLR() FT_ISBIT()
FT_BITCLR
FT_BITCLR()
Clear (reset) selected bit in a byte
Syntax
FT_BITCLR( <cByte>, <nBitPos> ) -> cByte
Arguments
<cByte> is a character from CHR(0) to CHR(255).
<nBitPos> is a number from 0 to 7 conforming to standard
right-to-left bit numbering convention and representing the
position of the bit within the byte.
Returns
Returns new byte, with designated bit cleared (reset).
If parameters are faulty, returns NIL.
Description
In effect, ANDs argument byte with a byte that has all bits set except
the target bit. If bit is already clear (0), it remains clear.
Note: Calls FT_ISBIT() which is also in this Library.
This function is presented to illustrate that bit-wise operations
are possible with Clipper code. For greater speed, write .C or
.ASM versions and use the Clipper Extend system.
Examples
This code would clear bit 4 in a byte represented by CHR(115):
cNewByte := FT_BITCLR( CHR(115), 4 )
? ASC( cNewbyte ) // result: 99
? cNewByte // result: 'c'
This code would clear bit 5 in the byte represented by letter 'A':
FT_BITCLR( 'A', 5 ) // result: 'A', since
// bit 5 already clear
For a demonstration of Clipper bit manipulations, compile and
link the program BITTEST.PRG in the Nanforum Toolkit source code.
Source: BITCLR.PRG
Author: Forest Belt, Computer Diagnostic Services, Inc.
See Also: FT_BITSET() FT_ISBIT()
