; Clip input lines on specified locations and write result to standard output. INCLUDE "/include/init.i" ; OPT D+ ; Local Equs MaxLineSize EQU 512 ; Variable storage STRUCT ArgArray,(4+1)*4 LONG StdIn LONG StdOut LONG ByteFetch LONG ReadBytesLeft LONG Count1 LONG Count2 LONG Delta1 LONG Delta2 LONG ID1StrPtr LONG ID2StrPtr LONG ID1Exclusive LONG ID2Exclusive SIZE ; Regs Delta EQUR D4 Count EQUR D5 LineBufPtr EQUR D6 LineBufLeft EQUR D7 LineEndPtr EQUR A2 IDStrPtr EQUR A3 ErrorStrPtr EQUR A4 ; Startup STACK 4000 INIT ; Let ARP interpret the commandline MOVE.L ComLineBase(GP),A0 MOVE.L ComLineSize(GP),D0 LEA HelpMsg(PC),A1 LEA ArgArray(GP),A2 LEA Template(PC),A3 MOVE.L A1,(A2) CALL GADS MOVE.L (A2),ErrorStrPtr TST.L D0 BEQ ErrorExit BMI ErrorExit ; Interpret the count values MOVE.L ArgArray+0*4(GP),A0 BSR GetSignedNum BEQ ErrorExit MOVE.L D0,Count1(GP) MOVE.L D1,Delta1(GP) MOVE.L ArgArray+2*4(GP),A0 BSR GetSignedNum BEQ ErrorExit MOVE.L D0,Count2(GP) MOVE.L D1,Delta2(GP) ; Interpret the ID strings LEA EmptyString(PC),A1 MOVE.L ArgArray+1*4(GP),D0 BNE.S ID1StringSpecified MOVE.L A1,D0 ID1StringSpecified: MOVE.L D0,A0 CMP.B #'x',(A0) BNE.S NoID1Exclusion ADDQ.L #1,A0 ADDQ.L #1,ID1Exclusive(GP) NoID1Exclusion: MOVE.L A0,ID1StrPtr(GP) MOVE.L ArgArray+3*4(GP),D0 BNE.S ID2StringSpecified MOVE.L A1,D0 ID2StringSpecified: MOVE.L D0,A0 CMP.B #'x',(A0) BNE.S NoID2Exclusion ADDQ.L #1,A0 ADDQ.L #1,ID2Exclusive(GP) NoID2Exclusion: MOVE.L A0,ID2StrPtr(GP) ; Open the standard input & output CALL Input MOVE.L D0,StdIn(GP) CALL Output MOVE.L D0,StdOut(GP) ; Allocate the read-line buffer LEA OutOfMem(PC),ErrorStrPtr MOVE.L #MaxLineSize+4+MaxLineSize,D0 ; 2 part buf with 0 term space. MOVEQ #0,D1 CALL ArpAllocMem MOVE.L D0,LineBufPtr BEQ ErrorExit ; ** This is an intelligent ReadLine routine. ; Reinitialize the line buffer. (First part of dual buffer space) DoForEachLine: LEA ReadError(PC),ErrorStrPtr MOVE.L LineBufPtr,LineEndPtr MOVE.L #MaxLineSize,LineBufLeft ; Extract lines from the readbuffer into the line buffer. BRA.S ExtractEntry CopyLineBytes: MOVE.L ByteFetch(GP),A0 ADDQ.L #1,ByteFetch(GP) SUBQ.L #1,ReadBytesLeft(GP) MOVE.B (A0),D0 CMP.B #10,D0 BEQ.S GotLine MOVE.B D0,(LineEndPtr)+ SUBQ.L #1,LineBufLeft BEQ.S GotLine ExtractEntry: TST.L ReadBytesLeft(GP) ; Stack vars 0 init BNE CopyLineBytes ; Refill the read buffer. MOVE.L StdIn(GP),D1 MOVE.L LineBufPtr,D2 MOVE.L #MaxLineSize,D3 ADD.L D3,D2 ADDQ.L #4,D2 CALL Read TST.L D0 BMI ErrorExit BNE.S NotYetDone CMP.L LineBufPtr,LineEndPtr BEQ.S Exit NotYetDone: MOVE.L D2,ByteFetch(GP) MOVE.L D0,ReadBytesLeft(GP) BNE CopyLineBytes ; Adjust end of line pointer and weed out empty lines GotLine: SUBQ.L #1,LineEndPtr CMP.L LineBufPtr,LineEndPtr BLO DoForEachLine ; Find the initial clip postition MOVE.L LineBufPtr,A0 MOVE.L Delta1(GP),Delta BPL.S InitialPosSet MOVE.L LineEndPtr,A0 InitialPosSet: MOVE.L Count1(GP),Count MOVE.L ID1StrPtr(GP),IDStrPtr BSR.S FindClipPosition BNE DoForEachLine MOVE.L A0,D3 ; Find the secondary clip postition. MOVE.L Delta2(GP),Delta MOVE.L Count2(GP),Count MOVE.L ID2StrPtr(GP),IDStrPtr BSR.S FindClipPosition BNE DoForEachLine ; Adjust for direction, adjust for exclusion and compute the length. MOVE.L ID1Exclusive(GP),D0 MOVE.L ID2Exclusive(GP),D1 CMP.L A0,D3 BHI.S InvertedDirection EXG D0,D1 EXG A0,D3 InvertedDirection: ADD.L D1,A0 SUB.L D0,D3 SUB.L A0,D3 BMI DoForEachLine ADDQ.L #2,D3 ; Terminate with a LF and write the line clip. LEA WriteError(PC),ErrorStrPtr MOVE.B #10,-1(A0,D3.L) MOVE.L StdOut(GP),D1 MOVE.L A0,D2 CALL Write CMP.L D0,D3 BNE.S ErrorExit WriteDone: ; Check if user hit ^C SkipWrite: SUB.L A1,A1 CALL CheckAbort MOVE.L A1,ErrorStrPtr TST.L D0 BNE.S ErrorExit BRA DoForEachLine ; Done, cleanup Exit: CLR.W ReturnCode(GP) SUB.L ErrorStrPtr,ErrorStrPtr ErrorExit: ; Display error string, if any, and exit MOVE.L ErrorStrPtr,D0 BEQ.S NoErrorMsg MOVE.L D0,A1 CALL Puts NoErrorMsg: RTS ; Subroutines ; This subroutine tried to find the CNTth position in the current line (relative ; to the initial position) which matches the ID string. ; I : A0 = Initial search position ; O : A0 = Clip position ; : Z=1 if search succeeded. ; : LineBufPtr,LineEndPtr,Delta,Count,IDStrPtr should be initialized FindClipPosition: ; Set the boundary to check with in D0 (Given position movement direction) MOVE.L LineBufPtr,D0 TST.L Delta BMI.S FetchedRelevantBoundary MOVE.L LineEndPtr,D0 FetchedRelevantBoundary: ; Check if all matches found or boundary reached. If not move current position. TST.L Count CheckNextByte: BEQ.S GotClipPosition NoByteMatch: CMP.L D0,A0 BEQ.S AtLineBoundary ADD.L Delta,A0 ; Check byte on the current position matched the ID string. TST.B (IDStrPtr) BEQ.S ByteMatched MOVE.L IDStrPtr,A1 MOVE.B (A0),D1 TryToMatchNextByte: CMP.B (A1)+,D1 BEQ.S ByteMatched TST.B (A1) BEQ NoByteMatch BRA TryToMatchNextByte ByteMatched: SUBQ.L #1,Count BRA CheckNextByte ; Done. Take care of the Z-flag. AtLineBoundary: TST.B (IDStrPtr) GotClipPosition: RTS ; This sub decodes an ASCII buffer containing a signed number to a positive ; number and a sign boolean. It also sets ErrorStrPtr to "Invalid count" ; I : A0 = Ptr ASCII buffer ; O : D0.L = Integer >= 0 ; : D1.L = +1 if positive, -1 if negative ; : Z = 1 if error GetSignedNum: LEA InvalidCnt(PC),ErrorStrPtr MOVEQ #-1,D1 CMP.B #'-',(A0)+ BEQ.S ConvertToLong MOVEQ #+1,D1 CMP.B #'+',-(A0) BNE.S ConvertToLong ADDQ.L #1,A0 ConvertToLong: MOVE.L D1,-(SP) CALL Atol MOVEM.L (SP)+,D1 RTS ; The string section Template: DC.B 'CNT1/a,ID1/k,CNT2/a,ID2/k',0 HelpMsg: DC.B 'Clip - Pipe through clipped lines.',10 DC.B 'Usage: Clip [ID1 [x]"charlist"] [ID2 [x]"charlist"]',0 OutOfMem: DC.B 'Out of memory!',0 InvalidCnt: DC.B 'Invalid count',0 ReadError: DC.B 'Error while reading',0 WriteError: DC.B 'Error while writing',0 EmptyString: DC.B 0 CNOP 0,2 END