openssl/crypto/bio/bio_lcl.h

#include <openssl/bio.h>

#if BIO_FLAGS_UPLINK==0
/* Shortcut UPLINK calls on most platforms... */
# define UP_stdin        stdin
# define UP_stdout       stdout
# define UP_stderr       stderr
# define UP_fprintf      fprintf
# define UP_fgets        fgets
# define UP_fread        fread
# define UP_fwrite       fwrite
# undef  UP_fsetmod
# define UP_feof         feof
# define UP_fclose       fclose

# define UP_fopen        fopen
# define UP_fseek        fseek
# define UP_ftell        ftell
# define UP_fflush       fflush
# define UP_ferror       ferror
# define UP_fileno       fileno

# define UP_open         open
# define UP_read         read
# define UP_write        write
# define UP_lseek        lseek
# define UP_close        close
#endif