png_set_write_fn 1249 contrib/libtests/pngimage.c    png_set_write_fn(dp->write_pp, &dp->written_file, write_function,
png_set_write_fn 1564 contrib/libtests/pngvalid.c       png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
png_set_write_fn  338 contrib/visupng/PngFile.c         png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
png_set_write_fn  821 example.c         png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
png_set_write_fn 1745 png.h          PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
png_set_write_fn  976 pngtest.c         png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
png_set_write_fn  549 pngwrite.c           png_set_write_fn(png_ptr, NULL, NULL, NULL);