1*2175Sjp161948=pod 2*2175Sjp161948 3*2175Sjp161948=head1 NAME 4*2175Sjp161948 5*2175Sjp161948BIO_s_file, BIO_new_file, BIO_new_fp, BIO_set_fp, BIO_get_fp, 6*2175Sjp161948BIO_read_filename, BIO_write_filename, BIO_append_filename, 7*2175Sjp161948BIO_rw_filename - FILE bio 8*2175Sjp161948 9*2175Sjp161948=head1 SYNOPSIS 10*2175Sjp161948 11*2175Sjp161948 #include <openssl/bio.h> 12*2175Sjp161948 13*2175Sjp161948 BIO_METHOD * BIO_s_file(void); 14*2175Sjp161948 BIO *BIO_new_file(const char *filename, const char *mode); 15*2175Sjp161948 BIO *BIO_new_fp(FILE *stream, int flags); 16*2175Sjp161948 17*2175Sjp161948 BIO_set_fp(BIO *b,FILE *fp, int flags); 18*2175Sjp161948 BIO_get_fp(BIO *b,FILE **fpp); 19*2175Sjp161948 20*2175Sjp161948 int BIO_read_filename(BIO *b, char *name) 21*2175Sjp161948 int BIO_write_filename(BIO *b, char *name) 22*2175Sjp161948 int BIO_append_filename(BIO *b, char *name) 23*2175Sjp161948 int BIO_rw_filename(BIO *b, char *name) 24*2175Sjp161948 25*2175Sjp161948=head1 DESCRIPTION 26*2175Sjp161948 27*2175Sjp161948BIO_s_file() returns the BIO file method. As its name implies it 28*2175Sjp161948is a wrapper round the stdio FILE structure and it is a 29*2175Sjp161948source/sink BIO. 30*2175Sjp161948 31*2175Sjp161948Calls to BIO_read() and BIO_write() read and write data to the 32*2175Sjp161948underlying stream. BIO_gets() and BIO_puts() are supported on file BIOs. 33*2175Sjp161948 34*2175Sjp161948BIO_flush() on a file BIO calls the fflush() function on the wrapped 35*2175Sjp161948stream. 36*2175Sjp161948 37*2175Sjp161948BIO_reset() attempts to change the file pointer to the start of file 38*2175Sjp161948using fseek(stream, 0, 0). 39*2175Sjp161948 40*2175Sjp161948BIO_seek() sets the file pointer to position B<ofs> from start of file 41*2175Sjp161948using fseek(stream, ofs, 0). 42*2175Sjp161948 43*2175Sjp161948BIO_eof() calls feof(). 44*2175Sjp161948 45*2175Sjp161948Setting the BIO_CLOSE flag calls fclose() on the stream when the BIO 46*2175Sjp161948is freed. 47*2175Sjp161948 48*2175Sjp161948BIO_new_file() creates a new file BIO with mode B<mode> the meaning 49*2175Sjp161948of B<mode> is the same as the stdio function fopen(). The BIO_CLOSE 50*2175Sjp161948flag is set on the returned BIO. 51*2175Sjp161948 52*2175Sjp161948BIO_new_fp() creates a file BIO wrapping B<stream>. Flags can be: 53*2175Sjp161948BIO_CLOSE, BIO_NOCLOSE (the close flag) BIO_FP_TEXT (sets the underlying 54*2175Sjp161948stream to text mode, default is binary: this only has any effect under 55*2175Sjp161948Win32). 56*2175Sjp161948 57*2175Sjp161948BIO_set_fp() set the fp of a file BIO to B<fp>. B<flags> has the same 58*2175Sjp161948meaning as in BIO_new_fp(), it is a macro. 59*2175Sjp161948 60*2175Sjp161948BIO_get_fp() retrieves the fp of a file BIO, it is a macro. 61*2175Sjp161948 62*2175Sjp161948BIO_seek() is a macro that sets the position pointer to B<offset> bytes 63*2175Sjp161948from the start of file. 64*2175Sjp161948 65*2175Sjp161948BIO_tell() returns the value of the position pointer. 66*2175Sjp161948 67*2175Sjp161948BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and 68*2175Sjp161948BIO_rw_filename() set the file BIO B<b> to use file B<name> for 69*2175Sjp161948reading, writing, append or read write respectively. 70*2175Sjp161948 71*2175Sjp161948=head1 NOTES 72*2175Sjp161948 73*2175Sjp161948When wrapping stdout, stdin or stderr the underlying stream should not 74*2175Sjp161948normally be closed so the BIO_NOCLOSE flag should be set. 75*2175Sjp161948 76*2175Sjp161948Because the file BIO calls the underlying stdio functions any quirks 77*2175Sjp161948in stdio behaviour will be mirrored by the corresponding BIO. 78*2175Sjp161948 79*2175Sjp161948=head1 EXAMPLES 80*2175Sjp161948 81*2175Sjp161948File BIO "hello world": 82*2175Sjp161948 83*2175Sjp161948 BIO *bio_out; 84*2175Sjp161948 bio_out = BIO_new_fp(stdout, BIO_NOCLOSE); 85*2175Sjp161948 BIO_printf(bio_out, "Hello World\n"); 86*2175Sjp161948 87*2175Sjp161948Alternative technique: 88*2175Sjp161948 89*2175Sjp161948 BIO *bio_out; 90*2175Sjp161948 bio_out = BIO_new(BIO_s_file()); 91*2175Sjp161948 if(bio_out == NULL) /* Error ... */ 92*2175Sjp161948 if(!BIO_set_fp(bio_out, stdout, BIO_NOCLOSE)) /* Error ... */ 93*2175Sjp161948 BIO_printf(bio_out, "Hello World\n"); 94*2175Sjp161948 95*2175Sjp161948Write to a file: 96*2175Sjp161948 97*2175Sjp161948 BIO *out; 98*2175Sjp161948 out = BIO_new_file("filename.txt", "w"); 99*2175Sjp161948 if(!out) /* Error occurred */ 100*2175Sjp161948 BIO_printf(out, "Hello World\n"); 101*2175Sjp161948 BIO_free(out); 102*2175Sjp161948 103*2175Sjp161948Alternative technique: 104*2175Sjp161948 105*2175Sjp161948 BIO *out; 106*2175Sjp161948 out = BIO_new(BIO_s_file()); 107*2175Sjp161948 if(out == NULL) /* Error ... */ 108*2175Sjp161948 if(!BIO_write_filename(out, "filename.txt")) /* Error ... */ 109*2175Sjp161948 BIO_printf(out, "Hello World\n"); 110*2175Sjp161948 BIO_free(out); 111*2175Sjp161948 112*2175Sjp161948=head1 RETURN VALUES 113*2175Sjp161948 114*2175Sjp161948BIO_s_file() returns the file BIO method. 115*2175Sjp161948 116*2175Sjp161948BIO_new_file() and BIO_new_fp() return a file BIO or NULL if an error 117*2175Sjp161948occurred. 118*2175Sjp161948 119*2175Sjp161948BIO_set_fp() and BIO_get_fp() return 1 for success or 0 for failure 120*2175Sjp161948(although the current implementation never return 0). 121*2175Sjp161948 122*2175Sjp161948BIO_seek() returns the same value as the underlying fseek() function: 123*2175Sjp1619480 for success or -1 for failure. 124*2175Sjp161948 125*2175Sjp161948BIO_tell() returns the current file position. 126*2175Sjp161948 127*2175Sjp161948BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and 128*2175Sjp161948BIO_rw_filename() return 1 for success or 0 for failure. 129*2175Sjp161948 130*2175Sjp161948=head1 BUGS 131*2175Sjp161948 132*2175Sjp161948BIO_reset() and BIO_seek() are implemented using fseek() on the underlying 133*2175Sjp161948stream. The return value for fseek() is 0 for success or -1 if an error 134*2175Sjp161948occurred this differs from other types of BIO which will typically return 135*2175Sjp1619481 for success and a non positive value if an error occurred. 136*2175Sjp161948 137*2175Sjp161948=head1 SEE ALSO 138*2175Sjp161948 139*2175Sjp161948L<BIO_seek(3)|BIO_seek(3)>, L<BIO_tell(3)|BIO_tell(3)>, 140*2175Sjp161948L<BIO_reset(3)|BIO_reset(3)>, L<BIO_flush(3)|BIO_flush(3)>, 141*2175Sjp161948L<BIO_read(3)|BIO_read(3)>, 142*2175Sjp161948L<BIO_write(3)|BIO_write(3)>, L<BIO_puts(3)|BIO_puts(3)>, 143*2175Sjp161948L<BIO_gets(3)|BIO_gets(3)>, L<BIO_printf(3)|BIO_printf(3)>, 144*2175Sjp161948L<BIO_set_close(3)|BIO_set_close(3)>, L<BIO_get_close(3)|BIO_get_close(3)> 145