Open a Space Telescope formatted (STSDAS) header file.
Saves the parameters required subsequent SX routines in
the common block Stcommn. Optionally save the header in
the string array Header, and the history in the string array
History. Open the data file associated with this
header on the same unit.
SXOPEN, Unit, Fname [, Header [,History] [,Access]]
Unit = IDL unit used for IO. Must be from 1 to 9.
Fname = File name of header file. Default extension
is .hhh for header files and .hhd for data
files. If an extension is supplied it must have the
form .xxh where xx are any alphanumeric characters. The
data file must have extension .xxd
No version number is allowed. Most recent versions
of the files are used.
Optional Input Parameter
Access = 'R' to open for read, 'W' to open for write.
Stcommn = Common block containing ST parameter blocks.
Optional Output Parameters
Header = 80 char by N string array containing the
names, values and comments from the FITS header.
Use the function SXPAR to obtain individual
History = String array containing the value of the
STCOMMN - Contains RESULT(20,10) where RESULT(i,LUN) =
0 - 121147 for consistency check, 1 - Unit for consistency,
2 - bitpix, 3 - naxis, 4 - groups (0 or 1), 5 - pcount,
6 - gcount, 7 - psize, 8 - data type as idl type code,
9 - bytes / record, 10 to 10+N-1 - dimension N,
17 = record length of file in bytes.
18 - # of groups written, 19 = gcount.
The data and header files are accessed.
Works only for disc files. The data file must have
must have the extension ".xxd" and the header file must
have the extension ".xxh" where x is any alphanumeric character
The header file is opened and each line is read.
Important parameters are stored in the output
parameter. If the last two parameters are specified
the parameter names and values are stored. The common
block STCOMMN is filled with the type of data, dimensions,
etc. for use by SXREAD.
If access is for write, each element of the header
array, which must be supplied, is written to the
header file. The common block is filled with
relevant parameters for SXWRITE. A keyword of "END"
ends the header.
Written, DMS, May, 1983.
D. Lindler Feb. 1990
Modified to allow var. record length header files.
D. Lindler April 1990 Conversion to new VMS IDL
Added /BLOCK when opening new .hhd file
Converted to IDL V5.0 W. Landsman September 1997
Recognize unsigned datatype for V5.1 or greater W. Landsman Jan 2000
Assume since V5.5 W. Landsman Sep 2006