idlastro / FITS ASCII & Binary Table I/O: FTAB_HELP

[Source code]

NAME
FTAB_HELP
PURPOSE
Describe the columns of a FITS binary or ASCII table extension(s).
CALLING SEQUENCE
FTAB_HELP, filename, [ EXTEN_No = , TEXTOUT= ]
        or
FTAB_HELP, fcb, [EXTEN_No=, TEXTOUT= ]
INPUTS
filename - scalar string giving name of the FITS file.  
fcb - FITS control block returned by a previous call to FITS_OPEN
OPTIONAL KEYWORD INPUTS
EXTEN_NO - integer scalar or vector specifying which FITS extensions 
        to display.    Default is to display all FITS extension.
TEXTOUT - scalar number (0-7) or string (file name) determining
        output device (see TEXTOPEN).  Default is TEXTOUT=1, output 
        to the user's terminal    
EXAMPLE
Describe the columns in the second and fourth extensions of a FITS 
file spec.fits and write the results to a file 'spec24.lis'
IDL> ftab_help,'spec.fits',exten=[2,4],t='spec24.lis'
SYSTEM VARIABLES
Uses the non-standard system variables !TEXTOUT and !TEXTUNIT
hich must be defined (e.g. with ASTROLIB) before compilation
NOTES
The behavior of FTAB_HELP was changed in August 2005 to display
all extensions by default, rather than just the first extension
PROCEDURES USED
FITS_READ, FITS_CLOSE, FITS_OPEN, FTHELP, TBHELP, TEXTOPEN, TEXTCLOSE
HISTORY
version 1  W. Landsman    August 1997
Corrected documentation W. Landsman   September 1997
Don't call fits_close if fcb supplied W. Landsman May 2001 
Default now is to display all extensions, EXTEN keyword can now
 be a vector   W. Landsman Aug 2005