TIFFWriteDirectory(3tiff)

NAME

       TIFFWriteDirectory,   TIFFRewriteDirectory,  TIFFCheckpointDirectory  -
       write the current directory in an open TIFF file

SYNOPSIS

       #include <tiffio.h>

       int TIFFWriteDirectory(TIFF *tif)
       int TIFFRewriteDirectory(TIFF *tif)
       int TIFFCheckpointDirectory(TIFF *tif)

DESCRIPTION

       TIFFWriteDirectory will write the contents of the current directory  to
       the  file  and setup to create a new subfile in the same file. Applica-
       tions only need to call TIFFWriteDirectory when writing  multiple  sub-
       files  to  a  single  TIFF  file.   TIFFWriteDirectory is automatically
       called by TIFFClose and TIFFFlush to write a modified directory if  the
       file is open for writing.

       The TIFFRewriteDirectory function operates similarly to TIFFWriteDirec-
       tory, but can be called with directories  previously  read  or  written
       that already have an established location in the file.  It will rewrite
       the directory, but instead  of  place  it  at  it's  old  location  (as
       TIFFWriteDirectory  would)  it  will place them at the end of the file,
       correcting the pointer from the preceeding directory or file header  to
       point  to  it's  new location.  This is particularly important in cases
       where the size of the directory and pointed to data has  grown,  so  it
       won't fit in the space available at the old location.

       The TIFFCheckpointDirectory writes the current state of the tiff direc-
       tory into the file to make what is  currently  in  the  file  readable.
       Unlike TIFFWriteDirectory, TIFFCheckpointDirectory does not free up the
       directory data structures  in  memory,  so  they  can  be  updated  (as
       strips/tiles  are  written)  and written again.  Reading such a partial
       file you will at worst get a tiff read error for the  first  strip/tile
       encountered that is incomplete, but you will at least get all the valid
       data in the file before that.  When the  file  is  complete,  just  use
       TIFFWriteDirectory as usual to finish it off cleanly.

RETURN VALUES

       1  is  returned when the contents are successfully written to the file.
       Otherwise, 0 is returned if an error was encountered when  writing  the
       directory contents.

DIAGNOSTICS

       All error messages are directed to the TIFFError(3TIFF) routine.

       Error  post-encoding  before  directory write.  Before writing the con-
       tents of the current directory, any pending data are flushed. This mes-
       sage indicates that an error occurred while doing this.

       Error  flushing  data  before directory write.  Before writing the con-
       tents of the current directory, any pending data are flushed. This mes-
       sage indicates that an error occurred while doing this.

       Cannot  write  directory,  out of space.  There was not enough space to
       allocate a temporary area for the directory that was to be written.

       Error writing directory count.  A write error occurred when writing the
       count of fields in the directory.

       Error  writing directory contents.  A write error occurred when writing
       the directory fields.

       Error writing directory link.  A write error occurred when writing  the
       link to the next directory.

       Error writing data for field "%s".  A write error occurred when writing
       indirect data for the specified field.

       Error writing TIFF header.  A  write  error  occurred  when  re-writing
       header at the front of the file.

       Error  fetching  directory  count.  A read error occurred when fetching
       the directory count field for a previous  directory.   This  can  occur
       when setting up a link to the directory that is being written.

       Error fetching directory link.  A read error occurred when fetching the
       directory link field for a previous directory.   This  can  occur  when
       setting up a link to the directory that is being written.

SEE ALSO

       TIFFOpen(3TIFF), TIFFError(3TIFF), TIFFReadDirectory(3TIFF), TIFFSetDi-
       rectory(3TIFF), libtiff(3TIFF)

       Libtiff library home page: http://www.remotesensing.org/libtiff/

libtiff                       September 26, 2001     TIFFWriteDirectory(3TIFF)