1=pod 2 3=head1 NAME 4 5BIO_s_file, BIO_new_file, BIO_new_fp, BIO_set_fp, BIO_get_fp, 6BIO_read_filename, BIO_write_filename, BIO_append_filename, 7BIO_rw_filename - FILE bio 8 9=head1 SYNOPSIS 10 11 #include <openssl/bio.h> 12 13 BIO_METHOD * BIO_s_file(void); 14 BIO *BIO_new_file(const char *filename, const char *mode); 15 BIO *BIO_new_fp(FILE *stream, int flags); 16 17 BIO_set_fp(BIO *b,FILE *fp, int flags); 18 BIO_get_fp(BIO *b,FILE **fpp); 19 20 int BIO_read_filename(BIO *b, char *name) 21 int BIO_write_filename(BIO *b, char *name) 22 int BIO_append_filename(BIO *b, char *name) 23 int BIO_rw_filename(BIO *b, char *name) 24 25=head1 DESCRIPTION 26 27BIO_s_file() returns the BIO file method. As its name implies it 28is a wrapper round the stdio FILE structure and it is a 29source/sink BIO. 30 31Calls to BIO_read() and BIO_write() read and write data to the 32underlying stream. BIO_gets() and BIO_puts() are supported on file BIOs. 33 34BIO_flush() on a file BIO calls the fflush() function on the wrapped 35stream. 36 37BIO_reset() attempts to change the file pointer to the start of file 38using fseek(stream, 0, 0). 39 40BIO_seek() sets the file pointer to position B<ofs> from start of file 41using fseek(stream, ofs, 0). 42 43BIO_eof() calls feof(). 44 45Setting the BIO_CLOSE flag calls fclose() on the stream when the BIO 46is freed. 47 48BIO_new_file() creates a new file BIO with mode B<mode> the meaning 49of B<mode> is the same as the stdio function fopen(). The BIO_CLOSE 50flag is set on the returned BIO. 51 52BIO_new_fp() creates a file BIO wrapping B<stream>. Flags can be: 53BIO_CLOSE, BIO_NOCLOSE (the close flag) BIO_FP_TEXT (sets the underlying 54stream to text mode, default is binary: this only has any effect under 55Win32). 56 57BIO_set_fp() set the fp of a file BIO to B<fp>. B<flags> has the same 58meaning as in BIO_new_fp(), it is a macro. 59 60BIO_get_fp() retrieves the fp of a file BIO, it is a macro. 61 62BIO_seek() is a macro that sets the position pointer to B<offset> bytes 63from the start of file. 64 65BIO_tell() returns the value of the position pointer. 66 67BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and 68BIO_rw_filename() set the file BIO B<b> to use file B<name> for 69reading, writing, append or read write respectively. 70 71=head1 NOTES 72 73When wrapping stdout, stdin or stderr the underlying stream should not 74normally be closed so the BIO_NOCLOSE flag should be set. 75 76Because the file BIO calls the underlying stdio functions any quirks 77in stdio behaviour will be mirrored by the corresponding BIO. 78 79=head1 EXAMPLES 80 81File BIO "hello world": 82 83 BIO *bio_out; 84 bio_out = BIO_new_fp(stdout, BIO_NOCLOSE); 85 BIO_printf(bio_out, "Hello World\n"); 86 87Alternative technique: 88 89 BIO *bio_out; 90 bio_out = BIO_new(BIO_s_file()); 91 if(bio_out == NULL) /* Error ... */ 92 if(!BIO_set_fp(bio_out, stdout, BIO_NOCLOSE)) /* Error ... */ 93 BIO_printf(bio_out, "Hello World\n"); 94 95Write to a file: 96 97 BIO *out; 98 out = BIO_new_file("filename.txt", "w"); 99 if(!out) /* Error occurred */ 100 BIO_printf(out, "Hello World\n"); 101 BIO_free(out); 102 103Alternative technique: 104 105 BIO *out; 106 out = BIO_new(BIO_s_file()); 107 if(out == NULL) /* Error ... */ 108 if(!BIO_write_filename(out, "filename.txt")) /* Error ... */ 109 BIO_printf(out, "Hello World\n"); 110 BIO_free(out); 111 112=head1 RETURN VALUES 113 114BIO_s_file() returns the file BIO method. 115 116BIO_new_file() and BIO_new_fp() return a file BIO or NULL if an error 117occurred. 118 119BIO_set_fp() and BIO_get_fp() return 1 for success or 0 for failure 120(although the current implementation never return 0). 121 122BIO_seek() returns the same value as the underlying fseek() function: 1230 for success or -1 for failure. 124 125BIO_tell() returns the current file position. 126 127BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and 128BIO_rw_filename() return 1 for success or 0 for failure. 129 130=head1 BUGS 131 132BIO_reset() and BIO_seek() are implemented using fseek() on the underlying 133stream. The return value for fseek() is 0 for success or -1 if an error 134occurred this differs from other types of BIO which will typically return 1351 for success and a non positive value if an error occurred. 136 137=head1 SEE ALSO 138 139L<BIO_seek(3)|BIO_seek(3)>, L<BIO_tell(3)|BIO_tell(3)>, 140L<BIO_reset(3)|BIO_reset(3)>, L<BIO_flush(3)|BIO_flush(3)>, 141L<BIO_read(3)|BIO_read(3)>, 142L<BIO_write(3)|BIO_write(3)>, L<BIO_puts(3)|BIO_puts(3)>, 143L<BIO_gets(3)|BIO_gets(3)>, L<BIO_printf(3)|BIO_printf(3)>, 144L<BIO_set_close(3)|BIO_set_close(3)>, L<BIO_get_close(3)|BIO_get_close(3)> 145