NAME

dfits -- display FITS file headers

USAGE

dfits fits_file file_list

PARAMETERS

fits_file

The FITS data source. This is either a template describing a list of disk files or a tape file specification of the form mt*[n], where mt indicates a mag tape device, * represents a density, and [n] is the tape file number. If the tape file number n is specified then only that file is converted. If the general tape device name is given, i.e. mta, mtb800, etc, then the files specified by the file_list parameter will be read from the tape.

file_list

The files to be read from a tape are specified by the file_list string. The string can consist of any sequence of file numbers separated by at least one of comma, or dash. A dash specifies a range of files. For example the string

"1,2,3-5,8-6"

will convert the files 1 through 8.

long_header = no

If this switch is set the full FITS header is printed on the standard output, and if it is reset the header is printed with the formats specified in the format file.

format_file = "ctio$src/dfits/format"

The format file to be used when the long_header switch is reset. This file is a list of keywords and formats, one per line, separated by commas. DFITS will print only the keywords listed, in the same order on the file, using the format specified for each one. No default format file is provided, so it must be created by the user. Keywords are not case sensitive. There is a special keyword named "FILENAME" that may be used to specify how to print the FITS file name. The formats are string of the form "W.DC", where "W" specifies the filed width, "D" the characters to print or precision, and "C" the format code or data type (string, integer, floating point number). All, "W", "D" and/or "C", may be omitted (including the dot). The default format is string. The following are the conventions for the "W" (field width) specification:

W = n      right justify in field of "n" characters, blank fill
  = -n     left justify in field of "n" characters, blank fill
  = 0n     zero fill at left (only if right justified)
absent, 0  use as much space as needed (D field sets width)

The format codes "C" are as follows:

d	decimal integer
e	exponential format ("D" specifies the precision)
f	fixed format ("D" specifies the number of decimal places)
g	general format ("D" specifies the precission)
h	hms format (hh:mm:ss.ss, "D" = number of decimal places)
m	(mm:ss.ss or hh:mm.mm)
o	octal integer
s	string ("D" specifies max characters to print)
x	hexadecimal integer

DESCRIPTION

FITS headers are read from the specified source; either disk or magnetic tape. At present non-standard FITS files (SIMPLE = F) and files containing group data are skipped and a warning message is issued. The FITS header may optionaly be printed on the standard output as either a full listing or a formatted listing. The first one prints all the header keywords for each FITS file in a multiline format. Each group of lines is associated with one FITS file. The formatted output is a multicolumn output, where each line is associated with a different FITS file. Each column contains the value for a particular header keyword. There is a title line at the beginning of the listing to label the columns. The width, contents, and title for each column are specified by the user in the format file. A null string is printed if a keyword is specified in the format file by the user, but not found in the FITS files. The default format file "ctio$src/dfits/format" provides almost the same output format than rfits with short_header=yes .

EXAMPLES

Display the headers of a set of FITS files on tape using formatted header output. The format file is the current default.

	cl> dfits mtb1600 1-999

Display the headers of a set of FITS file on disk, using long header format.

	cl> dfits fits* l+

Display the headers of a set of FITS files on tape, using formatted header output, specified in the file new_format.

	cl> dfits mtb1600 1-999  fo=new_format

Format file to print up to eigth characters of the filename, left justified, in field of ten characters, as a string. Up to three digits of the number of axis, right justified in a field of five characters, as a decimal integer. The origigin using as much space as needed, as a string (default). The universal time, right justified, using as much space as needed, as a real number in hour-minutes-seconds format. Up to thirty characters of the title, left justified in a field of as much space as needed. Remember that keywords are not case sensitive.

	FILENAME, -10.8
	NaXis, 5.3d
	origin
	AIRmass, 7.5f
	UT, h
	Comment, -.30

BUGS

1.- If the program runs out of memory to handle keywords, formats or header cards, it will discard silently the extra items.

2.- If two header cards have the same keyword or if there are multiline header cards, only the first card or line is printed.

SEE ALSO

dataio.rfits, dataio.wfits