NAME:
  rdstrarr
 PURPOSE:   (one line only)
  Read a file into a string array
 DESCRIPTION:
 CATEGORY:
  File I/O
 CALLING SEQUENCE:
  rdstrarr,file,str
 INPUTS:
  file - Name of file to read.
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  str - String array with contents of file.  Each line in the file is
             an entry in the array.  If the input file does not exist this
             will be returned with a value of !null.
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Southwest Research Institute, 2020/12/17