;------------------------------------------------------------------------------
; NAME: HEADPDS
;
; PURPOSE: To read a PDS label into an array variable
;
; CALLING SEQUENCE: Result = HEADPDS (filename [,/SILENT,/FILE,/FORMAT])
;
; INPUTS:
; Filename: Scalar string containing the name of the PDS file to read
; OUTPUTS:
; Result: PDS label array constructed from designated record
;
; OPTIONAL INPUT:
; SILENT: suppresses any messages from the procedure
; FILE: to be indicated if the file does not contain the label
; [for purposes other than reading a label]
; FORMAT: to be indicated if the file is ^STRUCTURE file
;
; EXAMPLES:
; To read a PDS file TEST.PDS into a PDS header array, lbl:
; IDL> lbl = HEADPDS("TEST.PDS",/SILENT)
; To read a PDS file that may not contain a header:
; IDL> lbl = HEADPDS("TEST2.TXT",/FILE)
; To read a PDS format file FORMAT.FMT from the ^STRUCTURE:
; IDL> fmt = HEADPDS("FORMAT.FMT", /FORMAT)
;
; PROCEDURES USED:
; Functions: POINTPDS, PDSPAR, CLEAN, ADDEOBJ
;
; MODIFICATION HISTORY:
; Written by: P. Khetarpal [Jan 24, 2003]
; Last modified: S. Martinez [Feb 01, 2009]
;
; For a complete list of modifications, see changelog.txt file.
;------------------------------------------------------------------------------
function get_struct_name, label, objindex
; initialize variables:
objectname = "-1"
; obtain the line of objindex and split into two using '=':
line = label[objindex]
segs = strsplit(line, '=', /extract)
; clean the second element of separated line
objectname = clean(segs[0],/space)
return, strmid(objectname,1)
end
function headpds, input_filename, SILENT = silent, FILE = file, FORMAT = format
; Modified: A.Cardesin 19 May 2005
; input_filename was changed during procedure
filename=input_filename
; error protection:
on_error, 2
on_ioerror, signal
; check for number of parameters in function call, must be >= 1:
if (n_params() lt 1) then begin
print, "Error: Syntax - result = HEADPDS ( filename " + $
"[,/SILENT,/FILE,/FORMAT] )"
return, "-1"
endif
; check for input of optional keywords:
silent = keyword_set(silent)
file = keyword_set(file)
format = keyword_set(format)
; check whether the file exists and can be opened:
openr, unit, filename, error = err, /get_lun
if (err lt 0) then begin
print, "Error: file " + filename + " could not be opened - "
print, " File either corrupted or invalid file name."
;;A.Cardesin Modified 8 Jun 2005
;;close and free logical unit before return
CATCH,error_status
IF (error_status NE 0) THEN BEGIN
CATCH,/CANCEL
return,"-1"
ENDIF
close,unit & free_lun, unit
return, "-1"
endif
; check for correct PDS label file:
if (~file && ~format) then begin
temp = bytarr(160)
readu, unit, temp
if ((strpos(string(temp), "PDS_VERSION_ID") lt 0) && $
(strpos(string(temp), "SFDU_LABEL") lt 0) && $
(strpos(string(temp), "XV_COMPATIBILITY") lt 0)) then begin
print, "Error: label must contain viable PDS_VERSION_ID keyword"
;;A.Cardesin Modified 8 Jun 2005
;;close and free logical unit before return
close,unit & free_lun, unit
return, "-1"
endif
endif
; initialize label variables:
lbl = "" ; holds the label string array
flag = 0 ; set to -1 when END keyword is encountered
objarr = "-1" ; holds the name of the OBJECTs in stack
objcount = 0 ; the number of objects to be processed
linecountflag = 0 ; the current number of lines, acts as a flag
; for storing values into lbl variable
; inform user of status:
if (~silent) then begin
print, "Now reading header: ", filename
endif
; set up file unit pointer:
point_lun, unit, 0
; start reading the file and read until one had reached the "END"
; keyword in the file and until it is not the end of the file:
while (~flag && ~(eof(unit))) do begin
; read one line from file:
; Note- readf removes all \r\n characters from end of ln during read:
ln = ""
readf, unit, ln
; if not reading a "FILE" type then look for OBJECT and END_OBJECT
; keywords and set values appropriately, also pad the lines to 80
; bytes:
if (~file) then begin
struct = addeobj(ln, objarr, objcount) ; external routine
if (struct.flag eq -1) then begin
;;A.Cardesin Modified 8 Jun 2005
;;close and free logical unit before return
close,unit & free_lun, unit
return, "-1"
endif
ln = struct.ln
objarr = struct.array
objcount = struct.count
endif else begin
ln += string([13B, 10B])
endelse
; if lbl array has not been constructed, then assign lbl to ln
; else concatenate ln to lbl array and increment linecount:
if (~linecountflag) then begin
lbl = ln
linecountflag += 1
endif else begin
lbl = [lbl, ln]
endelse
; now check for "END" keyword in ln:
ln2 = ln
ln2 = clean(ln2, /space) ; external routine
if (ln2 eq "END") then flag = 1
endwhile
; close the file unit and free the unit number:
close, unit
free_lun, unit
; ; process ^STRUCTURE object in label if any:
; struct = pdspar(lbl, "^STRUCTURE", COUNT=strcount, INDEX=strindex)
; if (strcount ne 0) then begin
; endobj = pdspar(lbl, "END_OBJECT", COUNT=eobjcount, INDEX=eobjindex)
;
; ; obtain the position where the contents of STRUCTURE file are
; ; to go in the lbl array, viz., before the last END_OBJECT keyword:
; structpos = where (eobjindex gt strindex[0])
; lblpos = eobjindex[structpos[0]]
; lastelem = n_elements(lbl) - 1
;
; ; obtain the pointer attributes for STRUCTURE, and read the file:
; pointer = pointpds (lbl, filename, "STRUCTURE") ; external routine
; if (pointer.flag eq -1) then begin
; print, "Error: structure pointer file missing"
; return, "-1"
; endif
;
; datafile = pointer.datafile
; fmtlabel = headpds (datafile, /format)
;
; ; insert fmtlabel into lbl array:
; lbl = [lbl[0:lblpos - 1], fmtlabel, lbl[lblpos:lastelem]]
; endif
; process ^STRUCTURE object in label if any:
struct = pdspar(lbl, "^STRUCTURE", COUNT=strcount, INDEX=strindex) ;; ^STRUCTURE
for i=0,strcount-1 do begin ;;santa
endobj = pdspar(lbl, "END_OBJECT", COUNT=eobjcount, INDEX=eobjindex)
; obtain the position where the contents of STRUCTURE file are
; to go in the lbl array, viz., before the last END_OBJECT keyword:
structpos = where (eobjindex gt strindex[i])
lblpos = eobjindex[structpos[0]]
lastelem = n_elements(lbl) - 1
; obtain the pointer attributes for STRUCTURE, and read the file:
objname = get_struct_name(lbl, strindex[i])
pointer = pointpds(lbl[strindex[i]-1:lastelem], filename, objname) ; external routine
if (pointer.flag eq -1) then begin
print, "Error: structure pointer file missing"
return, "-1"
endif
datafile = pointer.datafile
fmtlabel = headpds (datafile, /format)
; insert fmtlabel into lbl array:
lblpos = strindex[i] + 1
lbl = [lbl[0:lblpos - 1], fmtlabel, lbl[lblpos:lastelem]]
;strcount-- ;; 2008 May 20, smartinez: removed
struct = pdspar(lbl, "STRUCTURE", COUNT=strcount, INDEX=strindex)
endfor
return, lbl
; error processing:
signal:
on_ioerror, null
print, 'Error: unable to read file ' + filename
;;A.Cardesin Modified 8 Jun 2005
;;close and free logical unit before return
close,unit & free_lun, unit
return, -1
end