% @(#)read_file.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:51
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1992 European Southern Observatory
%.IDENT      read_file.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, READ/FILE
%.PURPOSE    On-line help file for the command: READ/FILE
%.VERSION    1.0  02-JUN-1992 : Creation, KB
%----------------------------------------------------------------
\se
SECTION./FILE
\es\co
READ/FILE                                            23-SEP-1992  KB
\oc\su
READ/FILE file_id cbuf_key [maxrd]
        reads one line of an ASCII file
\us\pu
Purpose:
          Read one line of an ASCII file which was opened before via 
	  the OPEN/FILE command.
\up\sy
Syntax:
          READ/FILE file_id cbuf_key [maxrd]
\ys\pa
          file_id = file id which was returned by a previous OPEN/FILE command
\ap\pa
          cbuf_key = name of char. keyword which is getting the contents of
              the file read operation
\ap\pa
          maxrd = max. no. of chars. to read; 
\\
              defaulted to size of `cbuf_key'
\ap\sa
See also:
          OPEN/FILE, CLOSE/FILE, WRITE/FILE
\as\no
Note:
          The actual no. of characters read from the file is stored as the
          2nd element of the integer keyword specified in the related
          OPEN/FILE command. If the end-of-file is reached, -1 will be
          stored there.
\\
          The `cbuf_key' keyword will be filled always from the beginning
          and padded with blanks until `maxrd'.
	  
	  The first time you use READ/FILE, only the first line will be read.
	  If you use READ/FILE a second time, the second line will be read.
	  By using the command n times, you'll be able to get access to the
	  nth line of the ascii file.    
\on\exs
Examples:
\ex
          READ/FILE 8 outputc 20
            Read ASCII file with file_id 8, char. keyword OUTPUTC will contain
            max. 20 chars. read from file. The 2nd element of the integer
            keyword specified in the related OPEN/FILE command will hold
            the actual no. of characters read; if at EOF, that no. will be -1.
\xe\ex
          READ/FILE {fctr(1)} outputc 20
            As above but use file_id which was stored in keyword fctr(1)
            (as indicated in the OPEN/FILE command) before.
\xe\sxe