TIFFERROR(3tiff) LibTIFF TIFFERROR(3tiff)

NAME

TIFFError - library error handling interface

SYNOPSIS

#include <tiffio.h>
#include <stdarg.h>

void TIFFError(const char *module, const char *fmt, ...)

void TIFFErrorExt(thandle_t fd, const char *module, const char *fmt,
...)

void TIFFErrorExtR(TIFF *tif, const char *module, const char *fmt,
...)

typedef void (*TIFFErrorHandler)(const char *module, const char *fmt,
va_list ap)

typedef void (*TIFFErrorHandlerExt)(thandle_t fd, const char *module,
const char *fmt, va_list ap)

typedef int (*TIFFErrorHandlerExtR)(TIFF *tif, void *user_data, const
char *module, const char *fmt, va_list ap)

TIFFErrorHandler TIFFSetErrorHandler(TIFFErrorHandler handler)

TIFFErrorHandlerExt TIFFSetErrorHandlerExt(TIFFErrorHandlerExt
handler)

DESCRIPTION

TIFFError() invokes the library-wide error handler function to
(normally) write an error message to stderr. The fmt parameter is a
printf() format string, and any number arguments can be supplied. The
module parameter is interpreted as a string that, if non-zero, should
be printed before the message; it typically is used to identify the
software module in which an error is detected.

Applications that desire to capture control in the event of an error
should use TIFFSetErrorHandler() to override the default error
handler. A NULL (0) error handler function may be installed to
suppress error messages.

Two more application-specific error handler callbacks are available,
each with different call parameters and passing parameters to the
handler. Each handler is also linked with an error message function,
i.e. TIFFErrorExt() and TIFFErrorExtR() if the application intends
to call the handler with those extended parameters.

TIFFErrorExt() provides a file handle as parameter. Within libtiff
TIFFErrorExt() is called passing tif->tif_clientdata as fd, which
represents the TIFF file handle (file descriptor). The
application-specific and library-wide handler for TIFFErrorExt() is
setup with TIFFSetErrorHandlerExt().

TIFFErrorExtR() (introduced with libtiff 4.5) is called with its TIFF
handle and thus provides access to a per-TIFF handle (re-entrant)
error handler. That means for different TIFF handles, different error
handlers can be setup. This application-specific handler can be setup
when a TIFF file is opened with one of the following functions:
TIFFOpenExt(), TIFFOpenWExt(), TIFFFdOpenExt() or
TIFFClientOpenExt(). Furthermore, a custom defined data structure
user_data for the error handler can be given along.

Please refer to TIFFOpenOptions for how to setup the
application-specific handler introduced with libtiff 4.5.

NOTE

Both functions TIFFError() and TIFFErrorExt() each attempt to call
both handler functions if they are defined. First TIFFErrorHandler()
is called and then TIFFErrorHandlerExt(). However, TIFFError()
passes a "0" as a file handle to TIFFErrorHandlerExt().

TIFFErrorExtR() tries first to call the per-TIFF handle defined error
handler. If TIFFErrorHandlerExtR() is not defined or returns 0,
TIFFErrorHandler() and then TIFFErrorHandlerExt() are called. From
libtiff 4.5 onwards TIFFErrorExtR() is used within the libtiff
library where the TIFF handle is available. Otherwise,
TIFFErrorExt() is used!

RETURN VALUES

TIFFSetErrorHandler() and TIFFSetErrorHandlerExt() returns a
reference to the previous error handler function.

TIFFErrorHandlerExtR() returns an integer as "stop" to control the
call of further error handler functions within TIFFErrorExtR():

+o 0: both functions TIFFErrorHandler() and TIFFErrorHandlerExt()
are called.

+o non-zero: no further error message function is called.

SEE ALSO

TIFFWarning (3tiff), TIFFOpen (3tiff), TIFFOpenOptions, libtiff
(3tiff), printf (3)

AUTHOR

LibTIFF contributors

COPYRIGHT

1988-2025, LibTIFF contributors

4.7 March 7, 2026 TIFFERROR(3tiff)