;+
; NAME:
;	Medit
; PURPOSE:
;	Edit Mathematica program fragment created by StPlotFix.PRO to
;       correct syntax errors. Optionally, tack on the rest of the
;       Mathematica code needed to create a full program.
; CATEGORY:
;	
; CALLING SEQUENCE:
;	Medit, file, test=test, append=append
; INPUTS:
;	file:	Fully-qualified path name of the Mathematica program
;		fragment file created by StPlotFix.PRO.
; OPTIONAL INPUTS:
;	None.
; KEYWORD PARAMETERS:
;	/test:	Write the new file to file 'Medit.m' to allow comparison
;		with the original file.
;       /append: Append the rest of the Mathematica code necessary to
;               have a full Mathematica program. Ths option is used when
;               the procedure is invoked by StPlotFix.
; OUTPUTS:
;	None.
; OPTIONAL OUTPUTS:
;	None.
; COMMON BLOCKS:
;	None.
; SIDE EFFECTS:
;	The specified file is opened and read. After being edited
;	internally a new file of the same name is written over the
;	original file, unless the /test keyword is set.
; RESTRICTIONS:
;	The named file must exist and have the expected structure.
; PROCEDURE:
;	The file is read as a byte string. The erroneous byte patterns
;	are located using StrPos, and the correct byte patterns are
;	inserted. Optionally, the remaining Mathematica code from
;       'starfit.m' is read and appended to the byte array before it is
;       written out.
; EXAMPLE:
;	Medit,'c:\data\starpos\g0601060.m',/test
; SEE ALSO:
;	StarID.PRO, StPlotFix.PRO
; MODIFICATION HISTORY:
; 	Written by:	DPSteele, Jan. 30/97.
;-

PRO Medit, file, test=test, append=append

@isitdos

IF Keyword_Set(test) THEN Stop

; Read in the file.

OpenR, lun, file, /Get_LUN
fs=FStat(lun)
nb=Fs.SIZE
bytes=BytArr(nb)
ReadU,lun,bytes
Free_LUN,lun

; Define the erroneous and correct byte patterns.

patt1=[123B, 13B, 10B, 123B]
len1=4
patt2=[125B, 44B, 13B, 10B, 125B]
len2=5

rpatt1=[123B, 32B, 123B]
rpatt2=[125B, 32B, 125B]

; Locate and replace the offending bytes.

pos1=StrPos(String(bytes),String(patt1))
IF pos1 LT 0 THEN BEGIN
    Message,'patt1 not found; aborting',/INFORMATIONAL
    Return
    ENDIF ELSE bytes=[bytes(0:pos1-1),rpatt1,bytes(pos1+len1:*)]

pos2=StrPos(String(bytes),String(patt2))
IF pos2 LT 0 THEN BEGIN
    Message,'patt2 not found; aborting',/INFORMATIONAL
    Return
    ENDIF ELSE bytes=[bytes(0:pos2-1),rpatt2,bytes(pos2+len2:*)]

; Load and append the rest of the Mathematica code from 'starfit.m'

IF Keyword_Set(append) THEN BEGIN
    mfile=starroot+dd+'starfit.m'
    mfile=rFindFile(mfile,count=nmf)
    IF nmf EQ 0 THEN BEGIN
        Message,mfile(0)+' not found',/INFORMATIONAL
        Return
        ENDIF ELSE mfile=mfile(0)
    OpenR,mlun,mfile,/Get_LUN
    mfs=FStat(mlun)
    mnb=mfs.SIZE
    mbytes=BytArr(mnb)
    ReadU,mlun,mbytes
    Free_LUN,mlun

    bytes=[bytes,mbytes]
    ENDIF

; Write out the corrected file.

IF Keyword_Set(test) THEN file=starroot+dd+'Medit.m'
OpenW,lun,file,/Get_LUN
WriteU,lun,bytes
Free_LUN,lun

Return
END