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docs/auparse_feed.3
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Steve Grubb
auparse: report feed consumption errors
27 июн 2026, 21:09
27 июн 2026, 21:092bb8900
.TH "AUPARSE_FEED" "3" "Sept 2023" "Red Hat" "Linux Audit API"
.SH NAME
auparse_feed \- feed data into parser
.SH "SYNOPSIS"
.B #include <auparse.h>
.sp
.nf
.BI "int auparse_feed(auparse_state_t *" au, const char *" data, size_t" data_len);"
.fi

.TP
.I au
The audit parse state
.TP
.I data
a buffer of data to feed into the parser, it is
.I data_len
bytes long. The data is copied in the parser, upon return the caller may free or reuse the data buffer.
.TP
.I data_len
number of bytes in
.I data

.SH "DESCRIPTION"

.I auparse_feed
supplies new data for the parser to consume.
.I auparse_init()
must have been called with a source type of AUSOURCE_FEED and a NULL pointer.
.I auparse_add_callback()
must be called before feeding data so that complete events have a consumer.
.br
.sp
The parser consumes as much data
as it can invoking a user supplied callback specified with
.I auparse_add_callback
with a cb_event_type of
.I AUPARSE_CB_EVENT_READY
each time the parser recognizes a complete event in the data stream. Data not fully parsed will persist and be
prepended to the next feed data. After all data has been feed to the parser
.I auparse_flush_feed
should be called to signal the end of input data and flush any pending parse data through the parsing system.
Malformed feed records are rejected and are not passed to the callback.
If malformed records are found, parsing continues for the rest of the
available feed data before
.I auparse_feed
returns an error.

.SH "RETURN VALUE"

Returns \-1 if an error occurs; otherwise, 0 for success.
When \-1 is returned,
.I errno
is set to indicate the error. The value of
.I errno
is meaningful only after an error return; callers should not assume it is
cleared after a successful call.
Applications that may run with libauparse from before audit-4.1.5 should set
.I errno
to 0 before calling
.I auparse_feed.
If
.I auparse_feed
returns \-1 and
.I errno
is still 0, the runtime library is using the older error behavior and did not
set
.I errno.
Clearing
.I errno
first avoids treating a pre-existing value as if it were set by
.I auparse_feed.

.SH "ERRORS"

.TP
.B EINVAL
The parser state is invalid, the parser was not initialized with
.B AUSOURCE_FEED,
the input arguments are invalid, or no callback has been registered.

.TP
.B ENOMEM
Memory allocation failed while buffering or parsing feed data.

.TP
.B EBADMSG
A malformed feed record was found. The malformed record was rejected and was
not passed to the callback. Parsing continues for the rest of the available
feed data before this error is returned.

.TP
.B EIO
An internal parser failure occurred without a more specific error code.

.SH "EXAMPLE"
.nf
void
auparse_callback(auparse_state_t *au, auparse_cb_event_t cb_event_type,
                 void *user_data)
{
    int *event_cnt = (int *)user_data;

    if (cb_event_type == AUPARSE_CB_EVENT_READY) {
        if (auparse_first_record(au) <= 0) return;
        printf("event: %d\\n", *event_cnt);
        printf("records:%d\\n", auparse_get_num_records(au));
        do {
            printf("fields:%d\\n", auparse_get_num_fields(au));
            printf("type=%d ", auparse_get_type(au));
            const au_event_t *e = auparse_get_timestamp(au);
            if (e == NULL) return;
            printf("event time: %lu.%u:%lu\\n",
                    (long unsigned)e\->sec, e\->milli, e\->serial);
            auparse_first_field(au);
            do {
                printf("%s=%s (%s)\\n", auparse_get_field_name(au),
                       auparse_get_field_str(au),
                       auparse_interpret_field(au));
            } while (auparse_next_field(au) > 0);
            printf("\\n");

        } while(auparse_next_record(au) > 0);
        (*event_cnt)++;
    }
}

main(int argc, char **argv)
{
    char *filename = argv[1];
    FILE *fp;
    char buf[256];
    size_t len;
    int *event_cnt = malloc(sizeof(int));

    au = auparse_init(AUSOURCE_FEED, 0);
    auparse_set_eoe_timeout(2);

    *event_cnt = 1;
    auparse_add_callback(au, auparse_callback, event_cnt, free);

    if ((fp = fopen(filename, "r")) == NULL) {
        fprintf(stderr, "could not open '%s', %s\\n", filename, strerror(errno));
        return 1;
    }

    while ((len = fread(buf, 1, sizeof(buf), fp))) {
        auparse_feed(au, buf, len);
    }
    auparse_flush_feed(au);
    auparse_destroy(au);
}
.fi

.SH "SEE ALSO"

.BR auparse_add_callback (3),
.BR auparse_flush_feed (3),
.BR auparse_feed_age_events (3),
.BR auparse_feed_has_data (3),
.BR auparse_metrics (3)


.SH AUTHOR
John Dennis