fxheader -- Produce a listing of a FITS file
fxheader input file_list
- input [file name template or device specification]
- The FITS data source. This is either a template describing a list of disk files.
- (long_header = no) [boolean]
- Print the full FITS header on the standard output?
- (count_lines = no) [boolean]
- Precede each line with a count.
- (short_header = yes) [boolean]
- Print only a short header? Lists files processed, their
dimensions, size of data type and scaling parameter on the standard output.
This task quickly lists one or a group of FITS files on disk. It reads only the header portion of each file, skipping the data. An optional parameter allows the user to list the full FITS header rather than a single line per file. For FITS files with extensions, you can specify the extension number to get a listing of one FITS unit. The keywords below represent the standard single line of information per processed file. You can change this by suplying a filename to the parameter format_file. Up to 80 characters per line are sent to the display terminal.
The following information will be listed in short headers by default. The first column is a name of an image header keyword or a special name the program will process to give you the requested column information.
EXT# Extension number EXTTYPE Input FITS diskname. EXTNAME EXTNAME value BITPIX Bits per pixels of the input data and the original datatype. (I,R,D,U,S) DIMENS Input FITS file dimensionality. BZERO Zero offset BSCALE Scale factor Notes: (I,R,D,U,S) refer to Integer, Real, Double, Unsigned and Short input data types, respectively. If the 'ieee' parameter is set, a minus (-) sign appears between the letter and the bits figure.DIMENS is the number of dimensions in the output FITS file; the format is "NxNxN" If the input file is a table, this keyword indicates the number of columns (Fields) and the number of rows in the table with the suffix F and R (e.g., 27Fx12R).
- (format_file = ) [file name]
- If you want to define your own output format--still limited to one line per
file--you can create an ASCII text file with some of the special
keywords, in addition to your own image header keyword that you want
to see in the display terminal or in the log file.
The format of the format file is as follow. One column with the keywords and a second with the field width and position of the values within the columns. The column format is similar to the Fortran print formatted statement.
The following special keywords are available:
EXT# -5.5 # (strign) Line counter (if 'long_header=no') EXTTYPE -10.10 # (string) The type of FITS unit BITPIX -5.5 # (string) Bit per pixels and (I,U,R,D,S). DIMENS -10.10 # (string) Output FITS file dimensionality. DATATYPE -8.8 # (string) Input file data type. BZERO -12.6g # (float) Scale offset value. BSCALE -12.6g # (float) Scale value. NBC -3.3 # (string) Number of cards available to insert # in header before expansion is mandatory.
In addition to these specials keywords, you can add your own that match the ones in the input FITS header.
1. Catalog a set of FITS extensions and FITS files.
fi> fxheader f1,gen.fit,bigf
2. Catalog a list of FITS files whose root is fits with long output and put a line count.
fi> fxheader fits* long+ count+
3. Catalog a FITS file with the extension number.
fi> fxheader yfile.fitswill list the 3rd extension (The primary FITS unit is ).
4. To use an alternate format file.
fi> fxheader mef.fits format=home$myformat.mipThere is also an alternative format file in fitsutil$format_off.mip that will list the header and pixel offset in byte units.
The NX and NY fields are 4 characters wide. A "*" character will be printed if the value in either field is greater than 9999. Use long headers in this case.