NAME

       VistaIOOpenInputFile, VistaIOOpenOutputFile - open file with error checking

SYNOPSIS

       #include <vistaio.h>

       FILE *VistaIOOpenInputFile (VistaIOStringConst filename, VistaIOBoolean nofail);

       FILE *VistaIOOpenOutputFile (VistaIOStringConst filename, VistaIOBoolean nofail);

ARGUMENTS

       filename  Specifies he name of the file to be opened.

       nofail    Specifies  whether  the  routine  should  exit the program if the file cannot be
                 opened.

DESCRIPTION

       These routines open a file while checking for failure and recognizing the special filename
       ``-'' as denoting the standard input or output stream.

       If  filename  is  NULL  or  it  is  the  string ``-'', either stdin or stdout is returned.
       Otherwise, an attempt is made to open the named file for either  reading  or  writing,  as
       appropriate. If the attempt is successful, the resulting file pointer is returned.

       The nofail argument determines what happens if a file cannot be opened. If nofail is FALSE
       then a warning message is issued and NULL is returned. If nofail  is  TRUE  then  a  fatal
       error message is issued and the program is terminated.

RETURN VALUES

       Either  routing  returns  a pointer to the opened FILE if successful. Otherwise it returns
       NULL or doesn't return at all (depending on nofail).

SEE ALSO

       VistaIOIdentifyFiles(3), VistaIOReadObjects(3), VistaIOWriteObjects(3),

DIAGNOSTICS

       ``Unable to open input/output file filename.''

AUTHOR

       Art Pope <pope@cs.ubc.ca>

       Adaption to vistaio: Gert Wollny <gw.fossdev@gmail.com>