Manual Pages for UNIX Operating System command usage for man BIO_s_file

OpenSSL                                      BIO_s_file(3openssl)



NNNNAAAAMMMMEEEE
     BIO_s_file, BIO_new_file, BIO_new_fp, BIO_set_fp,
     BIO_get_fp, BIO_read_filename, BIO_write_filename,
     BIO_append_filename, BIO_rw_filename - FILE bio

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
      #include 

      BIO_METHOD *   BIO_s_file(void);
      BIO *BIO_new_file(const char *filename, const char *mode);
      BIO *BIO_new_fp(FILE *stream, int flags);

      BIO_set_fp(BIO *b,FILE *fp, int flags);
      BIO_get_fp(BIO *b,FILE **fpp);

      int BIO_read_filename(BIO *b, char *name)
      int BIO_write_filename(BIO *b, char *name)
      int BIO_append_filename(BIO *b, char *name)
      int BIO_rw_filename(BIO *b, char *name)


DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     BIO_s_file() returns the BIO file method. As its name
     implies it is a wrapper round the stdio FILE structure and
     it is a source/sink BIO.

     Calls to BIO_read() and BIO_write() read and write data to
     the underlying stream. BIO_gets() and BIO_puts() are
     supported on file BIOs.

     BIO_flush() on a file BIO calls the fflush() function on the
     wrapped stream.

     BIO_reset() attempts to change the file pointer to the start
     of file using fseek(stream, 0, 0).

     BIO_seek() sets the file pointer to position ooooffffssss from start
     of file using fseek(stream, ofs, 0).

     BIO_eof() calls feof().

     Setting the BIO_CLOSE flag calls fclose() on the stream when
     the BIO is freed.

     BIO_new_file() creates a new file BIO with mode mmmmooooddddeeee the
     meaning of mmmmooooddddeeee is the same as the stdio function fopen().
     The BIO_CLOSE flag is set on the returned BIO.

     BIO_new_fp() creates a file BIO wrapping ssssttttrrrreeeeaaaammmm. Flags can
     be:  BIO_CLOSE, BIO_NOCLOSE (the close flag) BIO_FP_TEXT
     (sets the underlying stream to text mode, default is binary:
     this only has any effect under Win32).



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OpenSSL                                      BIO_s_file(3openssl)



     BIO_set_fp() set the fp of a file BIO to ffffpppp. ffffllllaaaaggggssss has the
     same meaning as in BIO_new_fp(), it is a macro.

     BIO_get_fp() retrieves the fp of a file BIO, it is a macro.

     BIO_seek() is a macro that sets the position pointer to
     ooooffffffffsssseeeetttt bytes from the start of file.

     BIO_tell() returns the value of the position pointer.

     BIO_read_filename(), BIO_write_filename(),
     BIO_append_filename() and BIO_rw_filename() set the file BIO
     bbbb to use file nnnnaaaammmmeeee for reading, writing, append or read
     write respectively.

NNNNOOOOTTTTEEEESSSS
     When wrapping stdout, stdin or stderr the underlying stream
     should not normally be closed so the BIO_NOCLOSE flag should
     be set.

     Because the file BIO calls the underlying stdio functions
     any quirks in stdio behaviour will be mirrored by the
     corresponding BIO.

EEEEXXXXAAAAMMMMPPPPLLLLEEEESSSS
     File BIO "hello world":

      BIO *bio_out;
      bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
      BIO_printf(bio_out, "Hello World\n");

     Alternative technique:

      BIO *bio_out;
      bio_out = BIO_new(BIO_s_file());
      if(bio_out == NULL) /* Error ... */
      if(!BIO_set_fp(bio_out, stdout, BIO_NOCLOSE)) /* Error ... */
      BIO_printf(bio_out, "Hello World\n");

     Write to a file:

      BIO *out;
      out = BIO_new_file("filename.txt", "w");
      if(!out) /* Error occurred */
      BIO_printf(out, "Hello World\n");
      BIO_free(out);

     Alternative technique:







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OpenSSL                                      BIO_s_file(3openssl)



      BIO *out;
      out = BIO_new(BIO_s_file());
      if(out == NULL) /* Error ... */
      if(!BIO_write_filename(out, "filename.txt")) /* Error ... */
      BIO_printf(out, "Hello World\n");
      BIO_free(out);


RRRREEEETTTTUUUURRRRNNNN VVVVAAAALLLLUUUUEEEESSSS
     BIO_s_file() returns the file BIO method.

     BIO_new_file() and BIO_new_fp() return a file BIO or NULL if
     an error occurred.

     BIO_set_fp() and BIO_get_fp() return 1 for success or 0 for
     failure (although the current implementation never return
     0).

     BIO_seek() returns the same value as the underlying fseek()
     function:  0 for success or -1 for failure.

     BIO_tell() returns the current file position.

     BIO_read_filename(), BIO_write_filename(),
     BIO_append_filename() and BIO_rw_filename() return 1 for
     success or 0 for failure.

BBBBUUUUGGGGSSSS
     BIO_reset() and BIO_seek() are implemented using fseek() on
     the underlying stream. The return value for fseek() is 0 for
     success or -1 if an error occurred this differs from other
     types of BIO which will typically return 1 for success and a
     non positive value if an error occurred.

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     BIO_seek(3), BIO_tell(3), BIO_reset(3), BIO_flush(3),
     BIO_read(3), BIO_write(3), BIO_puts(3), BIO_gets(3),
     BIO_printf(3), BIO_set_close(3), BIO_get_close(3)

















18/Sep/2000            Last change: 0.9.8o                      3