Mercurial > hg > Members > kono > nitros9-code
view level2/modules/kernel/fprsnam.asm @ 1345:1da8ab9ba433
Added consistent comments to each system call
| author | boisy |
|---|---|
| date | Wed, 17 Sep 2003 17:26:37 +0000 |
| parents | ca83286ded5b |
| children | 1451bc7ef0b9 |
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************************************************** * System Call: F$PrsNam * * Function: Parse a path name * * Modification to allow '-' in filenames by WG * * Input: X = Address of pathlist * * Output: X = Updated past optional "/" character * Y = Address of last character of pathlist + 1 * B = Length of pathlist * * Error: CC = C bit set; B = error code * FPrsNam ldx <D.Proc proc desc leay <P$DATImg,x Y=DAT image ptr ldx R$X,u X=name string bsr L0741 get it and length std R$D,u return length in D bcs L073E ..err stx R$X,u and X at name begin abx plus len L073E stx R$Y,u return Y=end of name ptr rts end. * Parse name L0741 pshs y save DAT image pointer lbsr AdjBlk0 go find map block... pshs x,y save X offset within block and Y block pointer bsr GoGetAXY go get byte at X in block Y... cmpa #'. is the first character a period? bne IsSlash no, do proper first character checking lbsr L0AC8 do a LDAXY, without changing X or Y bsr ChkFirst is the next character non-period? lda #'. restore the period character the LDAXY destroyed bcc Do.Loop if NON-period character, skip 1st char checks IsSlash cmpa #'/ is it a slash? bne NotSlash no, go keep X offset and block Y... bsr GetChar go get character... NotSlash bsr ChkFirst go check if valid first character... bcs NotValid not valid, go get next name start offset in X... Do.Loop clrb initialize character counter LastLoop incb add one character tsta last character in name string? bmi LastChar yes, go return valid... bsr GoGetAXY go get next character... bsr ChkValid go check if valid character... bcc LastLoop valid, go check if last character... LastChar andcc #^Carry bra RtnValid GetChar stx 2,s save current offset over old offset sty 4,s save current block pointer over old block pointer GoGetAXY lbra LDAXY go get byte at X in block Y in A, & return NextLoop bsr GetChar go get character... NotValid cmpa #', comma? beq NextLoop yes, go get next character... cmpa #C$SPAC space? beq NextLoop yes, go get next character... comb error, set Carry ldb #E$BNam 'Bad Name' error RtnValid puls x,y recover offset & pointer bra L0720 go do a similar exit routine ChkFirst pshs a save character anda #$7F drop msbit bra ChkRst skip dash for first character check ChkValid pshs a save character anda #$7F drop msbit cmpa #'. period? beq ValidChr yes, go return valid character... ChkRest cmpa #'- is it a dash? beq ValidChr yes, it's valid ChkRst cmpa #'z greater than "z"? bhi InvalidC yes, go return invalid character... cmpa #'a greater than or equal to "a"? bhs ValidChr yes, go return valid character... cmpa #'_ underscore? beq ValidChr yes, go return valid character... cmpa #'Z greater than "Z"? bhi InvalidC yes, go return invalid character... cmpa #'A greater than or equal to "A"? bhs ValidChr yes, go return valid character... cmpa #'9 greater than "9"? bhi InvalidC yes, go return invalid character... cmpa #'0 greater than or equal to "0"? bhs ValidChr yes, go return valid character... cmpa #'$ dollar symbol? beq ValidChr yes, go return valid character... InvalidC coma invalid character, set carry ValidChr puls a,pc