READFMT

       Quickly read a fixed format ASCII data file into IDL variables.

       Lines of data not meeting the specified format (e.g. comments) are
       ignored.
       To read a free format ASCII data file use the procedures
       READCOL or RDFLOAT.     To print (formatted or free) columns of data
       use the procedure FORPRINT.

       READFMT, name, fmt, v1,[ v2, v3, v4, ..., v25 ,
                          /SILENT, /DEBUG, SKIPLINE= , NUMLINE =]

       NAME - Name of ASCII data file.  An extension of .DAT is assumed,
               if not supplied.
       FMT - scalar string containing a valid FORTRAN read format.
               Must include a field length specification.   Cannot include
               internal parenthesis.  A format field must be included for
               each output vector.   Multiple format fields are allowed, but
               the repetition factor must be less than 100, (.i.e. 19X is
               allowed but 117X is illegal)
       Examples of valid FMT values are
               FMT = 'A7,3X,2I4'  or FMT = '1H ,5I7,2A7'
       Examples of INVALID FMT values are
               FMT = 'A7,B3'           ;'B' is not a valid FORTRAN format
               FMT = 'A7,2(I3,F5.1)'   ;Internal parenthesis not allowed
               FMT = 'A7,F,I'          ;Field length not included

       V1,V2,V3,V4... - IDL vectors to contain columns of data.
               Up to 25 output vectors may be read.  The type of the output
               vectors are specified by FMT.

       /SILENT - If this keyword is set and non-zero, then certain terminal
               output is suppressed while reading the file
       /DEBUG - Set this keyword to display additional information while
               reading the file.
       SKIPLINE - Scalar specifying number of lines to skip at the top of
               file before reading. Default is to start at first line
       NUMLINE - Scalar specifying number of lines in the file to read.
               Default is to read the entire file

       Each row in a fixed-format file POSITION.DAT contains a 5 character
       star name  and 6 columns of data giving an RA and Dec in sexigesimal
       format.   A possible format for such data might be
       IDL> FMT = 'A5,2I3,F5.1,2x,3I3'
       and the file could be quickly read with
       IDL> READFMT,'POSITION', fmt, name, hr, min, sec, deg, dmin, dsec
       NAME will be a string vector,SEC will be a floating point vector, and
       the other vectors will be of integer type.

       This procedure is designed for generality and not for speed.
       If a large ASCII file is to be read repeatedly, it may be worth
       writing a specialized reader.

       When reading a field with an integer format I, the output vector is
               byte  - if n = 1
               integer*2 - if 1 < n < 5
               integer*4  - in all other cases
       Octal ('O') and hexadecimal ('Z') formats are read into longwords

       GETTOK(), NUMLINES(), REMCHAR, ZPARCHECK

       Written         W. Landsman                 November, 1988
       Added SKIPLINE and NUMLINE keywords         March 92
       Allow up to 25 columns to be read           June 92
       Call NUMLINES() function                    Feb 1996
       Converted to IDL V5.0   W. Landsman   September 1997
       Recognize 'O' and 'Z' formats  W. Landsman   September 1997

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