#!/usr/local/rexx/rxx
/*
 *  write - a program to replace a specified line in a file
 *
 *  Syntax:   call write <file-name>, <line-number>, <string>
 *
 *            <file-name> is the name of the file to be updated
 *            <line-number> is the number of the line to be replaced
 *            <string> is the new data to be placed on that line
 *
 *
 *  If you wish to invoke write as a function, it should be modified
 *  to perform appropriate testing of return codes from linein() and
 *  lineout() and to return an appropriate value based on the results
 *  of these tests.
 *
 *
 *  Modification History:
 *
 *  25 Jul 94  twg  Initial implementation
 *
 *
 */

parse arg fname, line_num, string
do i = 1 to lines(fname)                       /* for every line in file */
   x = linein(fname)                                      /* read a line */
   if i \= line_num then queue x /* if not line to be replaced, queue it */
      else queue string                   /* or queue replacement string */
   end
call lineout fname                                         /* close file */
parse pull y                                           /* get first line */
call lineout fname, y, 1                            /* reinitialize file */
do queued()                                               /* do the rest */
   parse pull y
   call lineout fname, y
   end
call lineout fname                                         /* close file */
return