BIO_S_FILE(3)		     OpenSSL		    BIO_S_FILE(3)

NAME
     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

SYNOPSIS
      #include <openssl/bio.h>

      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)

DESCRIPTION
     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 sup-
     ported 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 ofs 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 mode the
     meaning of mode 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 stream. 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).

MirOS BSD #10-current	   2005-02-05				1

BIO_S_FILE(3)		     OpenSSL		    BIO_S_FILE(3)

     BIO_set_fp() set the fp of a file BIO to fp. flags 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
     offset 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
     b to use file name for reading, writing, append or read
     write respectively.

NOTES
     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.

EXAMPLES
     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:

MirOS BSD #10-current	   2005-02-05				2

BIO_S_FILE(3)		     OpenSSL		    BIO_S_FILE(3)

      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);

RETURN VALUES
     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.

BUGS
     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.

SEE ALSO
     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)

MirOS BSD #10-current	   2005-02-05				3

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