Replace idlcr8ascii.pro

idlcr8ascii.pro

-;Main Program Version: idlcr8ascii.pro v4.0b21, 20190514
+;Main Program Version: idlcr8ascii.pro v4.0b22, 20190806
 ;  Written by Ian Boyd for the AVDC - iboyd@astro.umass.edu
 ;
 ;Sub-versions:
@@ -76,6 +76,12 @@
 ;  v4.0b21 20190514  - Fix bug that occurred when GEOMS variable attribute information is missing from an 
 ;                    HDF4 file but written to the heap structure based on the contents of the file. Previously
 ;                    the variable attribute label was not written correctly.
+;  v4.0b22 20190806  - Provide support for reading netCDF4 files. Currently uses the HDF5 routines to do this
+;                    so need to account for features unique to netCDF4 such as; the inclusion of dimension
+;                    names; standard netCDF attribute names; empty attribute values that do not include a 
+;                    null termination character (which causes an error in the H5A_Read routine). New 
+;                    sub-routines include is_a_number_ascii, alpha_numeric_underscore, nc_dimension_chk,
+;                    file_format_a.  
 
 PRO idlcr8ascii_common
 ;Procedure to define the data COMMON block WIDGET_WIN_A, containing common variables
@@ -195,7 +201,7 @@ COMMON WIDGET_WIN_A
 
 ;procedure which provides an introduction message before starting the program.
 nhdr=46 & errtxt=STRARR(nhdr)
-vertxt=['idlcr8ascii-v4.0_Readme.pdf','v4.0b21 May 2019']
+vertxt=['idlcr8ascii-v4.0_Readme.pdf','v4.0b22 August 2019']
 errtxt[1]='Welcome to IDLcr8ASCII.  This program reads GEOMS compliant HDF4, HDF5 and netCDF files and'
 errtxt[2]='saves contents to either session memory, an output window (summary only) or to ASCII or formatted'
 errtxt[3]='files (also refer to '+vertxt[0]+').'
@@ -214,25 +220,25 @@ errtxt[17]='  /P or /POPUP - sends log input/output information to a Pop-up Dial
 errtxt[18]='  /L or /LOG - sends log input/output information to a file named idlcr8ascii.log'
 errtxt[19]='  /H4 - outputs contents of the input file as an HDF4 file'
 errtxt[20]='  /H5 - outputs contents of the input file as an HDF5 file'
-errtxt[21]='  /NC - outputs contents of the input file as a netCDF file'
-errtxt[23]='Example of command line input:  idlcr8ascii,DFSpec[,/F][,/D][,/C][,/P][,/L][,/H4][,/H5][,/NC]'
+errtxt[21]='  /NC3 - outputs contents of the input file as a netCDF3 file'
+errtxt[23]='Example of command line input:  idlcr8ascii,DFSpec[,/F][,/D][,/C][,/P][,/L][,/H4][,/H5][,/NC3]'
 errtxt[24]='  where ''DFSpec'' can either be a string array containing filenames or a scalar string containing a'
 errtxt[25]='  filespec or a single file name.'
 errtxt[26]='If running the full version of IDL, and input is a single HDF file, output can also be saved'
 errtxt[27]='  to session memory.  This can be done by calling idlcr8ascii with the following command line:'
-errtxt[28]='  idlcr8ascii,DFFile,GA,SDS[,/F][,/D][,/C][,/P][,/L][,/H4][,/H5][,/NC].'
+errtxt[28]='  idlcr8ascii,DFFile,GA,SDS[,/F][,/D][,/C][,/P][,/L][,/H4][,/H5][,/NC3].'
 errtxt[29]='DFFile can either be the name of an input file or '''' (in which case a DIALOG_BOX will open'
 errtxt[30]='  and prompt for the input filename).  ''GA'' is a returned string array containing the Global'
 errtxt[31]='  Attributes, and ''SDS'' is a returned structure using pointers containing the Variable'
 errtxt[32]='  Attribute Labels (sds.va_l), Variable Attribute Values (sds.va_v), and the Data (sds.data).
 errtxt[34]='Contacts -'
-errtxt[35]='  Ian Boyd, University of Massachusetts (iboyd@astro.umass.edu)'
-errtxt[36]='  Department of Astronomy, 619 Lederle GRC, University of Massachusetts'
-errtxt[37]='  710 North Pleasant St, Amherst, MA 01002, USA'
-errtxt[39]='  Ghassan Taha, AVDC Project Coordinator (ghassan.taha@nasa.gov)'
-errtxt[40]='  NASA Goddard Space Flight Center, Code 613.3'
-errtxt[41]='  Greenbelt, MD 20771, USA'
-errtxt[43]='AVDC Website: Tools and documentation available from http://avdc.gsfc.nasa.gov/Overview/index.html'
+errtxt[35]='  Ian Boyd, BC Scientific Consulting LLC (iboyd@astro.umass.edu)'
+errtxt[36]='  26 Campbells Rd'
+errtxt[37]='  Pine Hill, Dunedin 9010, New Zealand'
+errtxt[39]='  Ann Mari Fjaeraa, EVDC Project Manager (amf@nilu.no)'
+errtxt[40]='  Norwegian Institute for Air Research, Instituttveien 18'
+errtxt[41]='  Postbox 100, N-2027 KJELLER, NORWAY'
+errtxt[43]='EVDC Website: Tools and documentation available from http://evdc.esa.int/'
 errtxt[45]='To continue, please choose from the options below.'
 errtxt='        '+errtxt
 
@@ -240,7 +246,7 @@ errtxt='        '+errtxt
 demomode=LMGR(/DEMO) & optsens=1
 IF intype EQ -3 THEN xtxt=' - Command Line Input Error' ELSE xtxt=''
 base=WIDGET_BASE(Title='idlcr8ascii '+vertxt[1]+xtxt,Tlb_Frame_Attr=1,/Column) ;,Tab_Mode=1)
-wtxt=WIDGET_TEXT(base,xsize=88,ysize=25,/Scroll)
+wtxt=WIDGET_TEXT(base,xsize=90,ysize=25,/Scroll)
 
 tip='Left Mouse Click or Tab to entry and hit <Spacebar>'
 base2=WIDGET_BASE(base,/Nonexclusive)
@@ -252,8 +258,8 @@ IF demomode THEN BEGIN
 ENDIF ELSE logtext=logtext+'(will create the file IF it doesn''t exist)'
 h4text='Convert input file(s) to HDF4'
 h5text='Convert input file(s) to HDF5'
-nctext='Convert input file(s) to netCDF'
-fctext1='For the following options, any existing files will be overwritten, IDLcr8HDF must be in the IDL Search Path,'
+nctext='Convert input file(s) to netCDF3'
+fctext1='For the following 3 options, any existing files will be overwritten, IDLcr8HDF must be in the IDL Search Path,'
 fctext2='and a valid Table Attribute Values (TAV) file must be in the same directory as the Input file(s).'
 b1=WIDGET_BUTTON(base2,value=cattxt,uvalue='C',frame=3)
 b2=WIDGET_BUTTON(base2,value=poptext,uvalue='P',frame=3)
@@ -382,6 +388,54 @@ END ;Procedure Stop_With_Error_A
 
 
 
+FUNCTION is_a_number_ascii, value
+  ON_IOERROR, ConversionError
+  IF STRTRIM(value,2) EQ '' THEN RETURN, 0B
+  n=DOUBLE(value)
+  RETURN, 1B
+  ConversionError:
+  RETURN, 0B
+END
+
+
+
+FUNCTION alpha_numeric_underscore, str_value
+;Function that returns the input string with non-alphanumeric characters replaced with '_'
+; ----------
+;Written by Ian Boyd for the EVDC - iboyd@astro.umass.edu
+;
+;  History:
+;    20190806: Introduced - Version 4.0b22
+;
+;  Input: str_value: string
+;
+;  Returns: string with non-alphanumeric values replaced with '_'
+;
+;  Called by: Read_HDF_SDS
+;
+ON_IOERROR, ConversionError
+numb=BINDGEN(10)+48B ;0-9
+ucb=BINDGEN(26)+65B  ;A-Z
+lcb=BINDGEN(26)+97B  ;a-z
+str_value=STRING(str_value)
+new_str_value=str_value
+n_char=STRLEN(str_value)
+FOR i=0L,n_char-1L DO BEGIN
+  byt_value=BYTE(STRMID(new_str_value,i,1))
+  testn=(byt_value GE numb[0]) AND (byt_value LE numb[9])
+  testu=(byt_value GE ucb[0]) AND (byt_value LE ucb[25])
+  testl=(byt_value GE lcb[0]) AND (byt_value LE lcb[25])
+  IF (~testn) AND (~testu) AND (~testl) THEN $
+    STRPUT,new_str_value,'_',i
+ENDFOR
+RETURN, new_str_value
+ConversionError:
+RETURN, 'io_error'
+
+END ;Function alpha_numeric_underscore
+
+
+
 PRO infotxt_output_a, in0, in1
 ;Procedure called to report information relevant to the reading of the HDF file.
 ;This information can be reported to a Pop-up logging window, IDLDE output log window, and/or
@@ -415,10 +469,10 @@ CASE 1 OF
       infotxt=STRARR(3)
       IF LONG(in1[0]) EQ 0L THEN BEGIN
         infotxt[0]='  INFORMATION: Global Attribute DATA_VARIABLES not found or has no values.'
-        infotxt[1]='    Dataset listing order matches the order that the dataset is read in the HDF file.'
+        infotxt[1]='    Dataset listing order matches the order that the dataset is read in the GEOMS file.'
       ENDIF ELSE BEGIN
         infotxt[0]='  INFORMATION: Number of Global Attribute DATA_VARIABLES values ('+in1[0]+')'
-        infotxt[1]='    does not match the number of datasets saved to the HDF file ('+in1[1]+')'
+        infotxt[1]='    does not match the number of datasets saved to the GEOMS file ('+in1[1]+')'
       ENDELSE
       infotxt[2]='    Number of datasets determined from '+in1[2]+' call'
     END
@@ -737,6 +791,142 @@ END ;Function Julian_Date
 
 
 
+PRO nc_dimension_chk, ftype, sd_id, di, n_sds, dgi, n_sdsg
+;Procedure to check for netCDF dimension datasets. These will be quietly ignored during the
+;read process 
+; ----------
+;Written by Ian Boyd for the EVDC - iboyd@astro.umass.edu
+;
+;  History:
+;    20190806: Introduced - Version 4.0b22
+;
+;  Inputs: ftype - format type, HDF5 or netCDF
+;          sd_id - GEOMS file identifier number
+;          di    - index values for datasets
+;          n_sds - number of datasets determined by H5G_GET_NMEMBERS call
+;
+;  Outputs: dgi    - index values for GEOMS datasets (not generated by netCDF libraries)
+;           n_sdsg - number of GEOMS datasets
+;
+;  Called by: Read_HDF_SDS
+;
+dimen_names=['constant','independent_','_strlen']
+n_dn=N_ELEMENTS(dimen_names)
+ds_names=STRARR(n_sds) & gdi=INTARR(n_sds)-1
+FOR i=0,n_sds-1 DO BEGIN
+  IF ftype EQ 'H5' THEN sds_name=H5G_GET_MEMBER_NAME(sd_id,'/',di[i]) $
+  ELSE BEGIN ;netCDF file  
+    varstruct=NCDF_VARINQ(sd_id,i)
+    sds_name=varstruct.name
+  ENDELSE  
+  ds_names[i]=STRTRIM(STRLOWCASE(sds_name),2)
+ENDFOR
+
+FOR i=0,n_sds-1 DO BEGIN
+  dnicnt=0 & j=0
+  WHILE (dnicnt EQ 0) AND (j LE n_dn-1) DO $
+    IF STRPOS(ds_names[i],dimen_names[j]) NE -1 THEN dnicnt++ ELSE j++
+  IF dnicnt NE 0 THEN BEGIN
+    ;Check that names are actually netCDF dimension names o/w will treat as a dataset name
+    CASE j OF
+      0: IF ds_names[i] NE dimen_names[j] THEN dnicnt=0 ;i.e. not a netCDF dimension name
+      1: BEGIN
+           ;check that first part of the name is INDEPENDENT_ and the second part is a number
+           IF STRMID(ds_names[i],0,STRLEN(dimen_names[j])) NE dimen_names[j] $
+             THEN dnicnt=0 $
+           ELSE BEGIN
+             res=STRSPLIT(ds_names[i],'_',/EXTRACT,COUNT=cres)
+             res=[res,''] ;to ensure at least 2 extracted values in ds_names[i] 
+             if ~IS_A_NUMBER_ASCII(res[1]) THEN dnicnt=0 ; i.e. not a netCDF dimension name
+           ENDELSE        
+         END
+      2: BEGIN
+          ;check that first part of the name is a named dataset
+          res=STRSPLIT(ds_names[i],'_',/EXTRACT)
+          ni=WHERE(res[0] EQ ds_names,ncnt)
+          IF ncnt EQ 0 THEN dnicnt=0 ;i.e. not a netCDF dimension name
+         END
+    ENDCASE
+  ENDIF
+  IF dnicnt EQ 0 THEN gdi[i]=i ;i.e. this is a valid dataset name and not a netCDF dimension name
+ENDFOR
+
+dgi=WHERE(gdi NE -1,n_sdsg) ;dgi and n_sdsg are returned by the procedure
+
+END ;Procedure nc_dimension_chk
+
+
+
+FUNCTION file_format_a, infile
+;Function to identify the format of the input file - tests for HDF4, HDF5/netCDF4 and netCDF3.
+;netCDF4 files will be identified as HDF5 and read in using the HDF5 library
+; ----------
+;Written by Ian Boyd for the EVDC - iboyd@astro.umass.edu
+;
+;  History:
+;    20190806: Introduced - Version 4.0b22
+;
+;  Inputs: infile - Input GEOMS compliant file
+;
+;  Outputs: string identifying the type of file (H4, H5, NC) or XX for unidentified file
+;
+;  Called by: IDLCR8ASCII
+;
+;Markers
+;HDF4: 14   3  19   (1   0  16   0   1  95  98   0  30)
+;HDF5: 137  72  68  70 (13  10  26  10   0   0   0   0)
+;nc3:  67  68  70   (1   0   0   0   0   0   0   0  10)
+;nc4:  137  72  68  70 (13  10  26  10  (2   8   8   0))
+
+h4id=[14B, 3B, 19B]
+h5id=[137B, 72B, 68B, 70B]
+nc3id=[67B, 68B, 70B]
+
+;First test using start of file byte markers
+fid=BYTARR(4)
+openr,fu,infile,/GET_LUN
+readu,fu,fid
+FREE_LUN,fu
+
+idfound='XX'
+CASE 1 OF
+  ARRAY_EQUAL(fid[0:2],h4id): idfound='H4'
+  ARRAY_EQUAL(fid,h5id): idfound='H5'
+  ARRAY_EQUAL(fid[0:2],nc3id): idfound='NC'
+  ELSE:
+ENDCASE
+
+;Second test, if required, using IDL commands
+IF idfound EQ 'XX' THEN BEGIN
+  IF HDF_ISHDF(infile) EQ 1 THEN idfound='H4' $
+  ELSE IF FLOAT(!Version.Release) GE 5.6 THEN BEGIN
+    IF H5F_IS_HDF5(infile) EQ 1 THEN idfound='H5' ;netCDF4 or HDF5
+  ENDIF
+  IF idfound EQ 'XX' THEN BEGIN
+    ;final test for netCDF3
+    validname=1
+    CATCH, ncdferror ;To catch the error when attempting to open the file as a netCDF
+    ;Error Handler
+    IF ncdferror NE 0 THEN BEGIN ;not a netCDF file
+      validname=0
+      CATCH, /CANCEL
+    ENDIF
+    IF validname EQ 1 THEN BEGIN
+      fileid=NCDF_OPEN(infile)
+      ;If get to here then file is netCDF
+      CATCH, /CANCEL
+      NCDF_CLOSE,fileid
+      idfound='NC'
+    ENDIF
+  ENDIF
+ENDIF
+
+RETURN, idfound
+
+END ;File_Format_A
+
+
+
 PRO test_dim_order, va_name, va_value, va_type, sds_dim, rev_vd_vs
 ;Procedure to test the dimension ordering of any multi-dimensional datasets in the input DF file, and
 ;return correct ordering code (dimension ordering for idlcr8ascii uses IDL/Fortran convention)
@@ -752,7 +942,6 @@ PRO test_dim_order, va_name, va_value, va_type, sds_dim, rev_vd_vs
 ;    20141110: Fix bug that caused multi-dimensional array ordering to not be correctly identified
 ;              if the first dataset to be checked in the file had the same number of elements in
 ;              the array (e.g. was a set of Averaging Kernels) - Version 4.0b9
-
 ;
 ;  Inputs: va_name - An abbreviated version of the Variable Name; either 'VD' (VAR_DEPEND) or 'VS'
 ;                    (VAR_SIZE)
@@ -893,6 +1082,11 @@ PRO read_hdf_sds, ifile, ga, sds, catinfo
 ;    20190514  Fix bug that occurred when GEOMS variable attribute information is missing from an
 ;              HDF4 file but written to the heap structure based on the contents of the file. Previously
 ;              the variable attribute label was not written correctly - Version 4.0b21
+;    20190806  Provide support for reading netCDF4 files. Currently uses the HDF5 routines to do this
+;              so need to account for features unique to netCDF4 such as; the inclusion of dimension
+;              names; standard netCDF attribute names; empty attribute values that do not include a
+;              null termination character (which causes an error in the H5A_Read routine)
+;              - Version 4.0b22
 ;
 ;  Inputs: ifile - a string containing the name of the input file to be read in.
 ;          catinfo - a string array identifying the type of input file ('H4','H5','NC')
@@ -1264,10 +1458,18 @@ IF catinfo[0,0] EQ 'H4' THEN BEGIN
   !QUIET=0 ;Allow system error and information messages
   ;The HDF_SD_END function closes the SD interface to an HDF file.
   HDF_SD_END,sd_id
-ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
+ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 or netCDF4 format file
   stdfm=1 ;Boolean indicating standard AVDC/EVDC/NDACC H5 format or not
   dv_order=1 ;Boolean indicating whether Metadata Variable listing order matches DATA_VARIABLES values
   n_vn=0L ;Initialize the number of Variable Names in the standard format h5 file
+  
+  ;labels to quietly ignore if the file is netCDF4
+  nc4_ignore=['reference_list','dimension_list','class','name','_netcdf4dimid']
+  
+  ;Do bulk read so errors generated by netCDF4 inconsistencies can be identified without
+  ;crashing the program e.g. null string attribute values 
+  h5p=H5_PARSE(ifile) 
+  
   hdf_file_id=H5F_OPEN(ifile)
   sd_id=H5G_OPEN(hdf_file_id,'/')
 
@@ -1302,7 +1504,14 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
     FOR i=0L,n_ga-1L DO BEGIN
       ga_id=H5A_OPEN_IDX(sd_id,i)
       ga_name=H5A_GET_NAME(ga_id) & ga_name=STRTRIM(ga_name,2)
+            
+      ;test for valid attribute value - can be invalid if it is netCDF4 and equal to ''
+      gni=WHERE(TAG_NAMES(h5p) EQ ga_name)
+      attest=h5p.(gni[0])
+      IF attest._data EQ '<read error>' THEN ga_data='' $
+      ELSE BEGIN
         ga_data=H5A_READ(ga_id) & ga_data=STRTRIM(ga_data,2)
+      ENDELSE
       ;Check for _GLOSDS suffix and strip (added for compatibility with H4toH5 utility)
       IF STRMID(STRUPCASE(ga_name),STRLEN(ga_name)-7) EQ '_GLOSDS' THEN $
         ga_name=STRMID(ga_name,0,STRPOS(ga_name,'_',/Reverse_Search))
@@ -1318,6 +1527,8 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
   ENDIF
 
   IF n_sds NE 0L THEN BEGIN
+    NC_DIMENSION_CHK,'H5',sd_id,di,n_sds,dgi,n_sdsg ;check for netCDF dimension names (will quietly ignore)
+    di=dgi & n_sds=n_sdsg
     IF n_vn NE n_sds THEN $
       INFOTXT_OUTPUT_A,[0],[STRTRIM(n_vn,2),STRTRIM(n_sds,2),'H5G_GET_NMEMBERS']
       ;DATA_VARIABLES values not read successfully, or number of datasets given under DATA_VARIABLES
@@ -1330,6 +1541,9 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
     FOR i=0,n_sds-1 DO BEGIN
       sds_name=H5G_GET_MEMBER_NAME(sd_id,'/',di[i])
       ds_id=H5D_OPEN(sd_id,sds_name)
+      ;need to swap non-alphanumeric characters to '_' to match names from h5_parse for attribute values test
+      h5p_name=ALPHA_NUMERIC_UNDERSCORE(STRUPCASE(sds_name))
+ 
       IF sds_name EQ '' THEN sds_name='N/A'
       datasize=H5D_READ(ds_id)
       sds_dim=SIZE(datasize,/DIMENSIONS) & n_sds_dim=N_ELEMENTS(sds_dim)
@@ -1343,10 +1557,20 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
         vnf=0 & lcnt=0 & vnv=''
         ci=STRARR(4) ;array containing catalog attributes
         ;Read in Dataset Attributes
+        jj=0 ;use this index in the event of invalid attribute names (e.g. dimension_list from netCDF4 file)
         FOR j=0L,sds_natts-1L DO BEGIN
           da_id=H5A_OPEN_IDX(ds_id,j)
           da_name=H5A_GET_NAME(da_id) & da_name=STRTRIM(da_name,2)
-          va_value=H5A_READ(da_id)
+          
+          nc4i=WHERE(STRLOWCASE(da_name) EQ nc4_ignore,nc4icnt)
+          IF nc4icnt EQ 0 THEN BEGIN
+            ;test for valid attribute value - can be invalid if it is netCDF4 and equal to ''
+            gni=WHERE(TAG_NAMES(h5p) EQ h5p_name) ;Tag index from h5_parse read
+            attest=h5p.(gni[0])
+            gni=WHERE(TAG_NAMES(attest) EQ da_name)
+            attestx=attest.(gni[0])
+            IF STRTRIM(attestx._data,2) EQ '<read error>' THEN va_value='' $
+            ELSE va_value=H5A_READ(da_id)
             IF SIZE(va_value,/TYPE) EQ 7 THEN va_type='STRING' ELSE va_type='NON_STRING'
             schk=WHERE(STRUPCASE(da_name) EQ slabel,schkcnt)
             IF ((sds_type EQ 7) AND (schkcnt EQ 0)) OR ((sds_type NE 7) AND (va_type EQ 'STRING')) THEN $
@@ -1380,9 +1604,11 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
                 END
               ELSE:
             ENDCASE
+            jj++
+          ENDIF ;ELSE IF nc4i[0] EQ 4 THEN catinfo[0,0]='H5N' ;netCDF4 file - not implemented yet
           H5A_CLOSE,da_id
         ENDFOR
-        ci[3]=STRTRIM(sds_natts,2)
+        ci[3]=STRTRIM(jj,2)
         IF ci[0] EQ '' THEN ci[0]=sds_name
       ENDIF ELSE BEGIN ;No Attributes, so can only write dataset name to Metadata
         ci=[STRUPCASE(sds_name),'','','1'] & vnv=sds_name
@@ -1426,6 +1652,9 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
     notranspose=1 ;0/1 will change to 0 if the dataset needs to be transposed
     sds_name=H5G_GET_MEMBER_NAME(sd_id,'/',di[i])
     ds_id=H5D_OPEN(sd_id,sds_name)
+    ;need to swap non-alphanumeric characters to '_' to match names from h5_parse for attribute values test
+    h5p_name=ALPHA_NUMERIC_UNDERSCORE(STRUPCASE(sds_name))
+
     IF sds_name EQ '' THEN sds_name='N/A'
     datasize=H5D_READ(ds_id)
     sds_type=SIZE(datasize,/TYPE)
@@ -1434,10 +1663,20 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
 
     IF sds_natts NE 0L THEN BEGIN
       ;Read in Dataset Attributes
+      jj=0 ;use this index in the event of invalid attribute names (e.g. dimension_list fro netCDF4 file)
       FOR j=0L,sds_natts-1L DO BEGIN
         da_id=H5A_OPEN_IDX(ds_id,j)
         da_name=H5A_GET_NAME(da_id) & da_name=STRTRIM(da_name,2)
-        va_value=H5A_READ(da_id)
+        nc4i=WHERE(STRLOWCASE(da_name) EQ nc4_ignore,nc4icnt)
+        IF nc4icnt EQ 0 THEN BEGIN
+          ;test for valid attribute value - can be invalid if it is netCDF4 and equal to ''
+          gni=WHERE(TAG_NAMES(h5p) EQ h5p_name) ;Tag index from h5_parse read
+          attest=h5p.(gni[0])
+          gni=WHERE(TAG_NAMES(attest) EQ da_name)
+          attestx=attest.(gni[0])
+          IF STRTRIM(attestx._data,2) EQ '<read error>' THEN va_value='' $
+          ELSE va_value=H5A_READ(da_id)
+
           IF SIZE(va_value,/TYPE) EQ 7 THEN va_type='STRING' ELSE va_type='NON_STRING'
           schk=WHERE(STRUPCASE(da_name) EQ slabel,schkcnt)
           IF ((sds_type EQ 7) AND (schkcnt EQ 0)) OR ((sds_type NE 7) AND (va_type EQ 'STRING')) THEN $
@@ -1464,8 +1703,10 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
                 IF k EQ 0 THEN va_value=vs_v[k] ELSE va_value=va_value+';'+vs_v[k]
             ENDIF
           ENDIF
-        sds[oi[i],j].va_l=PTR_NEW(da_name)
-        sds[oi[i],j].va_v=PTR_NEW(va_value)
+          sds[oi[i],jj].va_l=PTR_NEW(da_name)
+          sds[oi[i],jj].va_v=PTR_NEW(va_value)
+          jj++
+        ENDIF
       ENDFOR
     ENDIF ELSE BEGIN ;No Attributes, so can only write dataset name to structure
       val='VAR_NAME'
@@ -1481,12 +1722,13 @@ ENDIF ELSE IF catinfo[0,0] EQ 'H5' THEN BEGIN ;HDF5 format file
 
   H5G_CLOSE,sd_id
   H5F_CLOSE,hdf_file_id
-ENDIF ELSE BEGIN ;netCDF file
+ENDIF ELSE BEGIN ;netCDF3 file
   ncdf_desc=['long_name']
   ncdf_std=['units','valid_range','_fillvalue']
+  ncdf_dimen=['constant','independent']
 
   dv_order=1 ;Boolean indicating whether Metadata Variable listing order matches DATA_VARIABLES values
-  n_vn=0L ;Initialize the number of Variable Names in the standard format h5 file
+  n_vn=0L ;Initialize the number of Variable Names in the standard format netCDF file
 
   fileid=NCDF_OPEN(ifile)
   ;Get number of global atts and variables
@@ -1523,6 +1765,10 @@ ENDIF ELSE BEGIN ;netCDF file
     ENDFOR
   ENDIF ELSE mv_dim=['']
 
+  di=INDGEN(n_sds)
+  NC_DIMENSION_CHK,'NC',fileid,di,n_sds,dgi,n_sdsg
+  di=dgi & n_sds=n_sdsg ;di contains index values of valid sds datasets
+
   IF n_vn NE n_sds THEN $
     INFOTXT_OUTPUT_A,[0],[STRTRIM(n_vn,2),STRTRIM(n_sds,2),'NCDF_INQUIRE']
     ;DATA_VARIABLES values not read successfully, or number of datasets given under DATA_VARIABLES
@@ -1533,7 +1779,7 @@ ENDIF ELSE BEGIN ;netCDF file
   catinfo=STRARR(n_sds,4) ;output info for catalog output
 
   FOR j=0,n_sds-1 DO BEGIN
-    varstruct=NCDF_VARINQ(fileid,j)
+    varstruct=NCDF_VARINQ(fileid,di[j])
     sds_natts=varstruct.natts
     IF sds_natts GT max_atts THEN max_atts=sds_natts
     sds_name=varstruct.name
@@ -1554,8 +1800,8 @@ ENDIF ELSE BEGIN ;netCDF file
       std_fnd=INTARR(n_aad)
       ;Read in Dataset Attributes
       FOR k=0,sds_natts-1 DO BEGIN
-        varattsname=NCDF_ATTNAME(fileid,j,k)
-        NCDF_ATTGET,fileid,j,varattsname,va_value
+        varattsname=NCDF_ATTNAME(fileid,di[j],k)
+        NCDF_ATTGET,fileid,di[j],varattsname,va_value
         va_name=STRUPCASE(varattsname)
         vavtype=SIZE(va_value,/TYPE)
 
@@ -1636,7 +1882,7 @@ ENDIF ELSE BEGIN ;netCDF file
   ;Put datasets and attributes into sds structure
   FOR j=0,n_sds-1 DO BEGIN
     notranspose=1 ;0/1 will change to 0 if the dataset needs to be transposed
-    varstruct=NCDF_VARINQ(fileid,j)
+    varstruct=NCDF_VARINQ(fileid,di[j])
     sds_name=varstruct.name
     IF sds_name EQ '' THEN sds_name='N/A'
     sds_natts=varstruct.natts
@@ -1644,13 +1890,13 @@ ENDIF ELSE BEGIN ;netCDF file
     sds_ndim=varstruct.ndims
 
     ;Extract data from a netCDF dataset and get size information
-    NCDF_VARGET,fileid,j,sds_data
+    NCDF_VARGET,fileid,di[j],sds_data
 
     IF sds_natts NE 0L THEN BEGIN
       ;Read in Dataset Attributes
       FOR k=0L,sds_natts-1L DO BEGIN
-        varattsname=NCDF_ATTNAME(fileid,j,k)
-        NCDF_ATTGET,fileid,j,varattsname,va_value
+        varattsname=NCDF_ATTNAME(fileid,di[j],k)
+        NCDF_ATTGET,fileid,di[j],varattsname,va_value
         va_name=STRUPCASE(varattsname)
         vavtype=SIZE(va_value,/TYPE)
 
@@ -1982,7 +2228,7 @@ PRO idlcr8ascii, ifile, ga, sds, reterr, $
 ;
 ;Program documentation, idlcr8ascii-v4.0_Readme.pdf, available on http://avdc.gsfc.nasa.gov.
 ;
-;Program sub-version 4.0b21 (20190514)
+;Program sub-version 4.0b22 (20190608)
 ; ----------
 ;Written by Ian Boyd for the AVDC - iboyd@astro.umass.edu
 ;
@@ -2024,6 +2270,8 @@ PRO idlcr8ascii, ifile, ga, sds, reterr, $
 ;              due to the program crashing when incorrectly identifying an HDF5 file as netCDF when
 ;              using IDL8.3 (OK for IDL6.4) - Version 4.0b10
 ;    20160213: Add CATCH, /CANCEL after idlcr8hdf call - Version 4.0b13
+;    20190806: Call routine FILE_FORMAT_A to determine the correct format of the input file(s)
+;              - Version 4.0b22
 ;
 ;  Inputs: ifile - a string array or filespec containing the name of the HDF file(s) to be read in
 ;
@@ -2041,7 +2289,7 @@ PRO idlcr8ascii, ifile, ga, sds, reterr, $
 ;                  idlcr8ascii.log
 ;            H4 - outputs contents of the input file as an HDF4 file
 ;            H5 - outputs contents of the input file as an HDF4 file
-;            NC - outputs contents of the input file as a netCDF file
+;            NC - outputs contents of the input file as a netCDF3 file
 ;
 ;  Outputs: ga - If included as a parameter in the command line, a string array containing the global
 ;                attribute labels and values extracted from a single HDF file.
@@ -2059,6 +2307,7 @@ PRO idlcr8ascii, ifile, ga, sds, reterr, $
 ;  Called by: Main Routine
 ;
 ;  Subroutines Called: INTRO_A (if program called without command line parameters)
+;                      FILE_FORMAT_A (to determine the format of the file(s))
 ;                      READ_HDF_SDS
 ;                      JDF_2_DATETIME
 ;                      OUTPUT_HDF_DATA (if output is not just to session memory only)
@@ -2078,10 +2327,10 @@ COMMON WIDGET_WIN_A
 
 ;Possible error messages for this procedure
 proname='IDLCR8ASCII procedure: '
-IF FLOAT(!Version.Release) GE 5.6 THEN errtxt='No valid HDF4, HDF5, or netCDF file selected.' $
+IF FLOAT(!Version.Release) GE 5.6 THEN errtxt='No valid HDF4, HDF5, or netCDF3 file selected.' $
 ELSE BEGIN
-  errtxt='No valid HDF4 or netCDF file selected '
-  errtxt=errtxt+'(Note: Input file can only be HDF4 or netCDF for IDL'+!Version.Release+').'
+  errtxt='No valid HDF4 or netCDF3 file selected '
+  errtxt=errtxt+'(Note: Input file can only be HDF4 or netCDF3 for IDL'+!Version.Release+').'
 ENDELSE
 lu=-1
 
@@ -2165,10 +2414,10 @@ ENDIF ELSE ifile=['']
 gi=WHERE(ifile NE '',nfile)
 IF nfile EQ 0L THEN BEGIN
   IF o3[2] EQ 'M' THEN $ ;pick one file only
-    ifile=DIALOG_PICKFILE(Filter=['*.hdf','*.h5'],/Must_Exist, $
+    ifile=DIALOG_PICKFILE(Filter=['*.hdf','*.h5','*.nc;*nc4'],/Must_Exist, $
           Title='Select HDF4, HDF5, or netCDF GEOMS Compatible Format File') $
   ELSE $ ;multiple selection permissable
-    ifile=DIALOG_PICKFILE(Filter=['*.hdf','*.h5','*.nc'],/Must_Exist, $
+    ifile=DIALOG_PICKFILE(Filter=['*.hdf','*.h5','*.nc;*.nc4'],/Must_Exist, $
           /Multiple_Files,Title='Select HDF4, HDF5, or netCDF GEOMS Compatible Format File(s)')
 ENDIF
 ;now check to see that files were actually selected, if not STOP!
@@ -2234,50 +2483,20 @@ FOR ndf=0L,nfile-1L DO BEGIN
     ENDELSE
   ENDFOR
 
+  ftype='XX'
   IF FILE_TEST(ifile[ndf]) EQ 1 THEN BEGIN
-    ;Test for netCDF
-    validname=1
-    CATCH, ncdferror ;To catch the error when attempting to open the file as a netCDF
-    ;Error Handler
-    IF ncdferror NE 0 THEN BEGIN ;not a netCDF file
-      validname=0
-      CATCH, /CANCEL
-    ENDIF
-    IF (validname EQ 1) AND (STRMID(STRUPCASE(ifile[ndf]),STRLEN(ifile[ndf])-3,3) EQ '.NC') THEN BEGIN
-      ;Need to add extra condition because H5 files were being accepted then crashing the program.
-      ;Try to open the file. If successful, file is valid.
-      fileid=NCDF_OPEN(ifile[ndf])
-      ;If get to here then file is netCDF
-      CATCH, /CANCEL
-      NCDF_CLOSE,fileid
-      catinfo[0,0]='NC'
-    ENDIF ELSE BEGIN ;Not netCDF so test for HDF4 or HDF5
-      IF HDF_ISHDF(ifile[ndf]) EQ 1 THEN catinfo[0,0]='H4' $ HDF4
-      ELSE IF FLOAT(!Version.Release) GE 5.6 THEN BEGIN ;Test for HDF5
-        IF H5F_IS_HDF5(ifile[ndf]) EQ 1 THEN catinfo[0,0]='H5' $
-        ELSE BEGIN
-          STOP_WITH_ERROR_A,o3[3]+proname,errtxt,lu
-          IF STRLEN(rerr) GT 2 THEN BEGIN
-            IF N_PARAMS() EQ 2 THEN ga=rerr ELSE reterr=rerr