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FITS File Open and Close Subroutines:
- 1
- Open an existing FITS file with readonly or readwrite access
FTOPEN(unit,filename,rwmode, > blocksize,status)
- 2
- Open an existing FITS file with readonly or readwrite access
and move to a following extension, if one was specified as
part of the filename. (e.g., 'filename.fits+2' or
'filename.fits[2]' will move to the 3rd HDU in the file).
Note that this routine differs from FTOPEN in that it does not
have the redundant blocksize argument.
FTNOPN(unit,filename,rwmode, > status)
- 3
- Reopen a FITS file that was previously opened with
FTOPEN, FTNOPN, or FTINIT. The newunit number
may then be treated as a separate file, and one may
simultaneously read or write to 2 (or more) different extensions in
the same file. The FTOPEN and FTNOPN routines (above) automatically
detects cases where a previously opened file is being opened again,
and then internally call FTREOPEN, so programs should rarely
need to explicitly call this routine.
FTREOPEN(unit, > newunit, status)
- 4
- Open and initialize a new empty FITS file
FTINIT(unit,filename,blocksize, > status)
- 5
- Create a new FITS file, using a template file to define its
initial size and structure. The template may be another FITS HDU
or an ASCII template file. If the input template file name
is blank, then this routine behaves the same as FTINIT.
The currently supported format of the ASCII template file is described
under the fits_parse_template routine (in the general Utilities
section), but this may change slightly later releases of
CFITSIO.
FTTPLT(unit, filename, tplfilename, > status)
- 6
- Flush internal buffers of data to the output FITS file
previously opened with ftopen or ftinit. The routine usually
never needs to be called, but doing so will ensure that
if the program subsequently aborts, then the FITS file will
have at least been closed properly.
FTFLUS(unit, > status)
- 7
- Close a FITS file previously opened with ftopen or ftinit
FTCLOS(unit, > status)
- 8
- Close and DELETE a FITS file previously opened with ftopen or ftinit.
This routine may be useful in cases where a FITS file is created, but
an error occurs which prevents the complete file from being written.
FTDELT(unit, > status)
- 9
- Get the value of an unused I/O unit number which may then be used
as input to FTOPEN or FTINIT. This routine searches for the first
unused unit number in the range from with 99 down to 50. This
routine just keeps an internal list of the allocated unit numbers
and does not physically check that the Fortran unit is available (to be
compatible with the SPP version of FITSIO). Thus users must not
independently allocate any unit numbers in the range 50 - 99
if this routine is also to be used in the same program. This
routine is provided for convenience only, and it is not required
that the unit numbers used by FITSIO be allocated by this routine.
FTGIOU( > iounit, status)
- 10
- Free (deallocate) an I/O unit number which was previously allocated
with FTGIOU. All previously allocated unit numbers may be
deallocated at once by calling FTFIOU with iounit = -1.
FTFIOU(iounit, > status)
- 11
- Parse the input filename and return the HDU number that would be
moved to if the file were opened with FTNOPN. The returned HDU
number begins with 1 for the primary array, so for example, if the
input filename = `myfile.fits[2]' then hdunum = 3 will be returned.
FITSIO does not open the file to check if the extension actually exists
if an extension number is specified. If an extension *name* is included
in the file name specification (e.g. `myfile.fits[EVENTS]' then this
routine will have to open the FITS file and look for the position of
the named extension, then close file again. This is not possible if
the file is being read from the stdin stream, and an error will be
returned in this case. If the filename does not specify an explicit
extension (e.g. 'myfile.fits') then hdunum = -99 will be returned,
which is functionally equivalent to hdunum = 1. This routine is mainly
used for backward compatibility in the ftools software package and is
not recommended for general use. It is generally better and more
efficient to first open the FITS file with FTNOPN, then use FTGHDN to
determine which HDU in the file has been opened, rather than calling
FTEXTN followed by a call to FTNOPN.
FTEXTN(filename, > nhdu, status)
- 12
- Return the name of the opened FITS file.
FTFLNM(unit, > filename, status)
- 13
- Return the I/O mode of the open FITS file (READONLY = 0, READWRITE = 1).
FTFLMD(unit, > iomode, status)
- 14
- Return the file type of the opened FITS file (e.g. 'file://', 'ftp://',
etc.).
FTURLT(unit, > urltype, status)
- 15
- Parse the input filename or URL into its component parts: the file
type (file://, ftp://, http://, etc), the base input file name, the
name of the output file that the input file is to be copied to prior
to opening, the HDU or extension specification, the filtering
specifier, the binning specifier, and the column specifier. Blank
strings will be returned for any components that are not present
in the input file name.
FTIURL(filename, > filetype, infile, outfile, extspec, filter,
binspec, colspec, status)
- 16
- Parse the input file name and return the root file name. The root
name includes the file type if specified, (e.g. 'ftp://' or 'http://')
and the full path name, to the extent that it is specified in the input
filename. It does not enclude the HDU name or number, or any filtering
specifications.
FTRTNM(filename, > rootname, status)
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