A2osX/SYS/KERNEL.S.STRING.txt

PR#3
PREFIX /A2OSX.BUILD
LOMEM $A00
INC 1
AUTO 6
*/--------------------------------------
* # StrLen.YA
* Returns Length of C-String
* ## In: 
*  Y,A = Ptr to CSTR
* ## Out: 
*  Y,A = String length
*\--------------------------------------
K.StrLen.YA		>STYA ZPPtr1

				ldy #0
				ldx #0
				
.1				lda (ZPPtr1),y
				beq .8
				iny
				bne .1
				inx
				inc ZPPtr1+1
				bra .1
				
.8				txa
				rts
*/--------------------------------------
* # StrCat
* Append SRC to DST
* ## In: 
*  PUSHW = Ptr to SRC (CSTR)
*  PUSHW = Ptr to DST (CSTR)
* ## Out: 
*  DST = DST+SRC
*\--------------------------------------
K.StrCat		jsr PullPtr1Ptr2
				
.1				lda (ZPPtr1)
				beq K.StrCpy.I
				
				inc ZPPtr1
				bne .1
				inc ZPPtr1+1
				bra .1
*/--------------------------------------
* # StrCpy
* Copy string
* ## In: 
*  PUSHW = Ptr to SRC (CSTR)
*  PUSHW = Ptr to DST (CSTR)
* ## Out: 
*  DST = SRC
*\--------------------------------------
K.StrCpy		jsr PullPtr1Ptr2
				
K.StrCpy.I		ldy #0
				
.1				lda (ZPPtr2),y
				sta (ZPPtr1),y
				beq .8
				iny
				bne .1
				inc ZPPtr2+1
				inc ZPPtr1+1
				bra .1
				
.8				rts
*/--------------------------------------
* # StrMatch
* Compare a String against pattern
* ## In: 
*   PUSHW = PTR to Pattern (e.g. '*test?.txt')
*   PUSHW = PTR to Src String 
* ## Out: 
*   CC : match
*   CS : no match
*\--------------------------------------
K.StrMatch		jsr PullPtr1Ptr2

				lda (ZPPtr2)			Get pattern 1st byte
                beq .8                  Match always if empty
				
				ldy #0

				bra .21
				
.1				inc ZPPtr2				Make PTR2 advance to next char 
                bne .2 
				inc ZPPtr2+1 

.2				lda (ZPPtr2)       		get pattern char 
				beq .41
				
.21				cmp #'*' 
				beq .5
                                        
.3				lda (ZPPtr1)			we must match ? or regular char, check if at end of string 
                beq .9                  no char left, exit with error 
                                        
				lda (ZPPtr2)       		get back pattern char 
				cmp #'?' 
				beq .4                  no need to compare, any char will match 
				cmp (ZPPtr1),y     		Regular Char, compare with string at Y 
				bne .9                  no match, exit 

				iny                     advance to next char to compare 
                                                				
.4				dex 					char matched, check if end of pattern 
				bne .1					continue if remaining char in pattern 

.41				lda (ZPPtr1),y 			end of pattern, but end of string ? 
				
				beq .8					yes, string matched entirely 
				bra .9					no, remaining char in string, no match 

.5				inc ZPPtr2				Make PTR2 advance to next char 
				bne .6 
				inc ZPPtr2+1
				lda (ZPPtr2)			we have '*', last char of pattern ? 
				beq .8					yes, match everything, including empty string 
                                        
.6				lda (ZPPtr2)       		get next char of pattern 
				cmp #'*'				another '*' ? 
				beq .5					yes, '**' = '*', go next char 
				cmp #'?'				'*?' ??? we must match a least one char 
				beq .3 
                                        
.7				lda (ZPPtr1),y			we need at least one remaining char in string, check if at end of string 
				beq .9					no chance to match ? or regular char 
                                        
				iny 
				lda (ZPPtr2)       		get again char in pattern 
				cmp (ZPPtr1),y 			compare with char in string 
                bne .7  	            not equal to next non wildcard in pattern 

				bra .4                  go check remaining char in pattern... 
                                        
.8				clc 
                rts 
                                        
.9              sec 
                rts 
*/--------------------------------------
* # StrUprYA/StrLwrYA
* Convert string to UPPERCASE/lowercase
* ## In:
*   Y,A = PTR to String (CSTR)
* ## Out:
*   Uppercased/lowercased String in Buffer
*\--------------------------------------
K.StrUprYA		ldx #0
				.HS 2C					bit abs
K.StrLwrYA		ldx #2
				>STYA ZPPtr1
				
				pha						save Y,A to restore them at exit
				phy
				
				ldy #0
				
.1				lda (ZPPtr1),y
				beq .8
				
				cmp K.PStrUprLwr,x
				bcc .2
				cmp K.PStrUprLwr+1,x
				bcs .2
				eor #$20
				sta (ZPPtr1),y
.2				iny
				bne .1
				inc ZPPtr1+1
				bra .1
				
.8				ply
				pla
				rts
*--------------------------------------
K.PStrUprLwr	.AS "azAZ"
*--------------------------------------
MAN
SAVE /A2OSX.SRC/SYS/KERNEL.S.STRING
LOAD /A2OSX.SRC/SYS/KERNEL.S
ASM