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Manual Pages  — AU_IO


au_fetch_tok, au_print_tok, au_print_flags_tok, au_read_rec – perform I/O involving an audit record



Basic Security Module User Library (libbsm, -lbsm)


#include <bsm/libbsm.h>

au_fetch_tok(tokenstr_t *tok, u_char *buf, int len);

au_print_tok(FILE *outfp, tokenstr_t *tok, char *del, char raw, char sfrm);

au_print_flags_tok(FILE *outfp, tokenstr_t *tok, char *del, int oflags);

au_read_rec(FILE *fp, u_char **buf);


These interfaces support input and output (I/O) involving audit records, internalizing an audit record from a byte stream, converting a token to either a raw or default string, and reading a single record from a file.

The au_fetch_tok() function reads a token from the passed buffer buf of length len bytes, and returns a pointer to the token via tok.

The au_print_tok() function prints a string form of the token tok to the file output stream outfp, either in default mode, or raw mode if raw is set non-zero. The delimiter del is used when printing. The au_print_flags_tok() function is a replacement for au_print_tok(). The oflags controls how the output should be formatted and is specified by or'ing the following flags:

AU_OFLAG_NONE Use the default form.
AU_OFLAG_NORESOLVE Leave user and group IDs in their numeric form.
AU_OFLAG_RAW Use the raw, numeric form.
AU_OFLAG_SHORT Use the short form.
AU_OFLAG_XML Use the XML form.

The flags options AU_OFLAG_SHORT and AU_OFLAG_RAW are exclusive and should not be used together.

The au_read_rec() function reads an audit record from the file stream fp, and returns an allocated memory buffer containing the record via *buf, which must be freed by the caller using free(3).

A typical use of these routines might open a file with fopen(3), then read records from the file sequentially by calling au_read_rec(). Each record would be broken down into components tokens through sequential calls to au_fetch_tok() on the buffer, and then invoking au_print_flags_tok() to print each token to an output stream such as stdout. On completion of the processing of each record, a call to free(3) would be used to free the record buffer. Finally, the source stream would be closed by a call to fclose(3).


On success, au_fetch_tok() returns 0 while au_read_rec() returns the number of bytes read. Both functions return -1 on failure with errno set appropriately.


free(3), libbsm(3)


The OpenBSM implementation was created by McAfee Research, the security division of McAfee Inc., under contract to Apple Computer, Inc., in 2004. It was subsequently adopted by the TrustedBSD Project as the foundation for the OpenBSM distribution.

The au_print_flags_tok() function was added by Stacey Son as a replacement for the au_print_tok() so new output formatting flags can be easily added without changing the API. The au_print_tok() is obsolete but remains in the API to support legacy code.


This software was created by Robert Watson, Wayne Salamon, and Suresh Krishnaswamy for McAfee Research, the security research division of McAfee, Inc., under contract to Apple Computer, Inc.

The Basic Security Module (BSM) interface to audit records and audit event stream format were defined by Sun Microsystems.


The errno variable may not always be properly set in the event of an error.

AU_IO (3) May 30, 2018

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