1.Dd $Mdocdate: February 16 2015 $ 2.Dt BIO_S_NULL 3 3.Os 4.Sh NAME 5.Nm BIO_s_null 6.Nd null data sink 7.Sh SYNOPSIS 8.In openssl/bio.h 9.Ft BIO_METHOD * 10.Fo BIO_s_null 11.Fa void 12.Fc 13.Sh DESCRIPTION 14.Fn BIO_s_null 15returns the null sink BIO method. 16Data written to the null sink is discarded, reads return EOF. 17.Sh NOTES 18A null sink BIO behaves in a similar manner to the 19.Xr null 4 20device. 21.Pp 22A null bio can be placed on the end of a chain to discard any data 23passed through it. 24.Pp 25A null sink is useful if, for example, an application wishes 26to digest some data by writing through a digest bio 27but not send the digested data anywhere. 28Since a BIO chain must normally include a source/sink BIO, 29this can be achieved by adding a null sink BIO to the end of the chain. 30.Sh RETURN VALUES 31.Fn BIO_s_null 32returns the null sink BIO method. 33