'===========================================================================
' Subject: SWAP NAMES OF TWO FILES            Date: 09-17-97 (16:32)       
'  Author: John A. Kiernan                    Code: ASIC                   
'  Origin: kiernan@uwo.ca                   Packet: ASIC.ABC
'===========================================================================
rem  SWAPNAME.ASI  Compilation: ASICC SWAPNAME
rem  Exchange the names of two files, with error trapping etc.
rem  Version 1.1 September 1997 (improved on-line help)

rem   Submitted to A.B.C. 15th September 1997

rem  Both files must be in the current directory. SWAPNAME.COM
rem  can be in any directory that is in the PATH statement.

DIM WrongCharacter$(4)
DATA "\",":","*","?"
 FOR n = 1 TO 4
   READ WrongCharacter$(n)
 NEXT n
BadEntry=0
TempFileName$="TEMPOR.ARY"

CommandLineTail$=COMMAND$
CommandLineTail$=LTRIM$(CommandLineTail$)
CommandLineTail$=RTRIM$(CommandLineTail$)
CommandLineTail$=UCASE$(CommandLineTail$)
     MoreInfo=INSTR(CommandLineTail$,"/?")
       IF MoreInfo>0 THEN
         GOSUB MoreInfo:
         GOTO TheEnd:
       ENDIF
WholeLength=LEN(CommandLineTail$)
FirstTerm=INSTR(CommandLineTail$," ")
FirstTerm=FirstTerm-1
  IF FirstTerm < 1 THEN
    GOSUB BadEntry:
  ENDIF
  IF BadEntry > 0 THEN TheEnd:
FirstTerm$=LEFT$((CommandLineTail$,FirstTerm)
SecondTerm=WholeLength-FirstTerm
SecondTerm$=RIGHT$(CommandLineTail$,SecondTerm)
SecondTerm$=LTRIM$(SecondTerm$)
SecondTerm=LEN(SecondTerm$)
  IF SecondTerm < 1 THEN
    GOSUB BadEntry:
  ENDIF
  IF BadEntry > 0 THEN TheEnd:
  ThirdTerm=INSTR(SecondTerm$," ")
    IF ThirdTerm > 0 THEN
      GOSUB BadEntry:
    ENDIF
    IF BadEntry > 0 THEN TheEnd:

  TestTerm$=FirstTerm$
  GOSUB CheckTerm:
    IF BadEntry > 0 THEN TheEnd:
  TestTerm$=SecondTerm$
  GOSUB CheckTerm:
    IF BadEntry > 0 THEN TheEnd:
  GOSUB CheckExist:
    IF BadEntry > 0 THEN TheEnd:

rem Renaming files

 NAME FirstTerm$ AS TempFileName$
   IF ERROR > 0 THEN
     GOSUB RenameError:
     GOTO TheEnd:
   ENDIF
 NAME SecondTerm$ AS FirstTerm$
   IF ERROR > 0 THEN
     GOSUB RenameError:
     GOTO TheEnd:
   ENDIF
 NAME TempFileName$ AS SecondTerm$
   IF ERROR > 0 THEN
     GOSUB RenameError:
     GOTO TheEnd:
   ENDIF

 COLOR 3,0
 PRINT ""
 PRINT "File names swapped."
 COLOR 7,0
TheEnd:
END

rem  Subroutines

BadEntry:
COLOR 11,0
PRINT ""
PRINT "   SWAPNAME.COM         ";
COLOR 3,0
PRINT "Version 1.1  by J. A. Kiernan (c) September 1997"
PRINT ""
COLOR 11,0
PRINT "   Exchange the names of two files."
PRINT ""
COLOR 15,0
PRINT "   Usage: ";
COLOR 14,0
PRINT "SWAPNAME File1 File2  ";
COLOR 7,0
PRINT "where File1 and File2 are"
PRINT "          The names of the two files. Both files must be in"
PRINT "          the current directory of the logged drive, and the"
PRINT "          names must not include wildcard (* or ?) characters."
PRINT ""
  IF MoreInfo=0 THEN
    COLOR 15,0
    PRINT "          Enter the command SWAPNAME /? for more information"
    COLOR 7,0
  ENDIF
rem ***PRINT ""
BadEntry=1
RETURN

CheckTerm:
    FOR n = 1 TO 4
       BadEntry=INSTR(TestTerm$,WrongCharacter$(n))
         IF BadEntry > 0 THEN WrongThingFound:
    NEXT n
    GOTO NoWrongThings:
 WrongThingFound:
    GOSUB BadEntry:
 NoWrongThings:
    RETURN

CheckExist:
   FileName$=FirstTerm$
   Fil$=FIND FIRST(FirstTerm$,0)
          IF ERROR > 0 THEN
            GOSUB NotThere:
            BadEntry=1
          ENDIF
   FileName$=SecondTerm$
   Fil$=FIND FIRST(SecondTerm$,0)
          IF ERROR > 0 THEN
            GOSUB NotThere:
            BadEntry=2
          ENDIF
     IF BadEntry > 0 THEN
       GOSUB BadEntry:
     ENDIF
   RETURN

NotThere:
  Gap$=SPACE$(35)
  COLOR 3,0
  PRINT Gap$;
  PRINT FileName$;
  PRINT " not found."
  COLOR 7,0
  RETURN

MoreInfo:
GOSUB BadEntry:
PRINT "     Only three DOS commands are needed to exchange the names of a"
PRINT "     pair of files. However, a single wrongly typed character or a"
PRINT "     failure to appreciate the fine points of DOS syntax can generate"
PRINT "     error messages that are not easily understood.  The SWAPNAME"
PRINT "     utility detects any errors that would make the exchange of file"
PRINT "     names impossible."
PRINT ""
RETURN

RenameError:
PRINT ""
COLOR 14,0
PRINT "An error occurred in renaming: ";
COLOR 11,0
 IF ERROR < 5 THEN
   PRINT "File not found"
 ENDIF
 IF ERROR > 4 THEN
   PRINT "Access denied"
 ENDIF
COLOR 15,0
PRINT "One of the files may have been copied to ";
PRINT TempFileName$
PRINT "Check the directory entries."
PRINT ""
COLOR 7,0
RETURN