NAME

fstruct -- Output the names, sizes, etc of extensions in input file

USAGE

        fstruct infile

DESCRIPTION

This task outputs to either the screen or to an output file the name, type, and size of the requested extension, as well as the values of the pcount and gcount keywords. Optionally, select information about the columns contained in the extension can be output. The information can be requested for an individual extension, or for the whole input file. The information is also written into hidden parameters in the parameter file. If more than one extension's information is requested, the last the values for the last extension are saved. Whether the file is a FITS format file or not is returned in the ISFITS parameter, and whether the requested extension exists or not is returned by the TYPE parameter.

PARAMETERS

INFILE [filename]

The filename and extension of the file for which information is requested. If no extension is specified, or if [*] is requested, information on all extensions is displayed.

(OUTFILE=STDOUT) [filename]

The filename of an the output file. If STDOUT is specified, the output is directed to the screen. If preceeded by !, an existing file of the same name will be overwritten.

(colinfo=yes) [boolean]

If true, information (name, format, dimesions, units, minimum and maximum values) about each column will be written to the OUTFILE location.

(isfits) [boolean]

This parameter is returned true if the file is a FITS file.

(totalhdu) [integer]

The Total number of HDUs in the FITS file.

(hdunum) [integer]

The HDU number of the current HDU (Primary array = 0).

(type) [string]

The type (PRIMARY/BINTABLE/TABLE/IMAGE) of the requested extension. If the extension specified does not exist, a "" will be returned.

(extname) [string]

The extension name of the requested extension.

(bitpix) [integer]

The value of the BITPIX keyword.

(naxis) [integer]

The value of the NAXIS keyword.

(naxis1) [integer]

The size of the first dimension (images) or the number of bytes in each row (tables). Set equal to 1 if the keyword does not exist.

(naxis2) [integer]

The size of the second dimension (images) or the number of rows (tables). Set equal to 1 if the keyword does not exist.

(naxis3) [integer]

The size of the third dimension for images, ignored for tables. Set equal to 1 if the keyword does not exist.

(naxis4) [integer]

The size of the fourth dimension for images, ignored for tables. Set equal to 1 if the keyword does not exist.

(tfields) [integer]

For table extension, the number of columns is returned.

(pcount) [integer]

The value of the PCOUNT keyword is returned.

(gcount) [integer]

The value of the GCOUNT keyword is returned.

(clobber=no) [boolean]

If true, an existing file with the same name as the requested output file will be overwritten.

EXAMPLES

1. Display information on all the extension in asbn.fits

             ft> fstruct asbn.fits

BUGS

SEE ALSO

ftlist. fv, the interactive FITS file editor, can also be used to view the structure of a FITS file.

CATEGORY