Sortix nightly manual
This manual documents Sortix nightly, a development build that has not been officially released. You can instead view this document in the latest official manual.
|BIO_S_FILE(3)||Library Functions Manual||BIO_S_FILE(3)|
#include <openssl/bio.h>const BIO_METHOD *
BIO_s_file(void); BIO *
BIO_new_file(const char *filename, const char *mode); BIO *
BIO_new_fp(FILE *stream, int flags); long
BIO_set_fp(BIO *b, FILE *fp, int flags); long
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);
BIO_s_file() returns the BIO file method. As its name implies, it is a wrapper around the stdio FILE structure and it is a source/sink BIO. Calls to BIO_read(3) and BIO_write(3) read and write data to the underlying stream. BIO_gets(3) and BIO_puts(3) are supported on file BIOs. BIO_flush(3) on a file BIO calls the fflush(3) function on the wrapped stream. BIO_reset(3) attempts to change the file pointer to the start of file using
fseek(stream, 0, 0). BIO_seek(3) sets the file pointer to position ofs from the start of the file using
fseek(stream, ofs, 0). BIO_eof(3) calls feof(3). Setting the
BIO_CLOSEflag calls fclose(3) 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 for the stdio function fopen(3). The
BIO_CLOSEflag is set on the returned BIO.
BIO_new_fp() creates a file BIO wrapping stream. Flags can be:
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).
BIO_set_fp() sets the file pointer of a file BIO to fp. flags has the same meaning as in
BIO_set_fp() is a macro.
BIO_get_fp() retrieves the file pointer of a file BIO, it is a macro. BIO_seek(3) is a macro that sets the position pointer to offset bytes from the start of file. BIO_tell(3) returns the value of the position pointer.
BIO_rw_filename() set the file BIO b to use file name for reading, writing, append or read write respectively. When wrapping stdout, stdin, or stderr, the underlying stream should not normally be closed, so the
BIO_NOCLOSEflag should be set. Because the file BIO calls the underlying stdio functions, any quirks in stdio behaviour will be mirrored by the corresponding BIO. On Windows,
BIO_new_files() reserves for the filename argument to be UTF-8 encoded. In other words, if you have to make it work in a multi-lingual environment, encode file names in UTF-8.
BIO_s_file() returns the file BIO method.
BIO_new_fp() return a file BIO or
NULLif an error occurred.
BIO_get_fp() return 1 for success or 0 for failure (although the current implementation never returns 0). BIO_seek(3) returns the same value as the underlying fseek(3) function: 0 for success or -1 for failure. BIO_tell(3) returns the current file position.
BIO_rw_filename() return 1 for success or 0 for failure.
BIO *bio_out; bio_out = BIO_new_fp(stdout, BIO_NOCLOSE); BIO_printf(bio_out, "Hello World\n");
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");
BIO *out; out = BIO_new_file("filename.txt", "w"); if(!out) /* Error occurred */ BIO_printf(out, "Hello World\n"); BIO_free(out);
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);
BIO_append_filename() first appeared in SSLeay 0.6.0.
BIO_new_fp() first appeared in SSLeay 0.8.0. All these functions have been available since OpenBSD 2.4.
BIO_rw_filename() first appeared in SSLeay 0.9.1 and has been available since OpenBSD 2.6. BIO_reset(3) and BIO_seek(3) are implemented using fseek(3) on the underlying stream. The return value for fseek(3) 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.
|December 19, 2018||Debian|