POSIX_TRACE_GET_ATTR(3P)

PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
posix_trace_get_attr, posix_trace_get_status — retrieve the trace attributes or trace status (TRACING)

SYNOPSIS

#include <trace.h>

int posix_trace_get_attr(trace_id_t trid, trace_attr_t *attr);
int posix_trace_get_status(trace_id_t trid,
    struct posix_trace_status_info *statusinfo);

DESCRIPTION
The posix_trace_get_attr() function shall copy the attributes of the active trace stream identified by trid into the object pointed to by the attr argument. If the Trace Log option is supported, trid may represent a pre-recorded trace log.

The posix_trace_get_status() function shall return, in the structure pointed to by the statusinfo argument, the current trace status for the trace stream identified by the trid argument. These status values returned in the structure pointed to by statusinfo shall have been appropriately read to ensure that the returned values are consistent. If the Trace Log option is supported and the trid argument refers to a pre-recorded trace stream, the status shall be the status of the completed trace stream.

Each time the posix_trace_get_status() function is used, the overrun status of the trace stream shall be reset to POSIX_TRACE_NO_OVERRUN immediately after the call completes. If the Trace Log option is supported, the posix_trace_get_status() function shall behave the same as when the option is not supported except for the following differences:

*   If the trid argument refers to a trace stream with log, each time the posix_trace_get_status() function is used, the log overrun status of the trace stream shall be reset to POSIX_TRACE_NO_OVERRUN and the flush_error status shall be reset to zero immediately after the call completes.

*   If the trid argument refers to a pre-recorded trace stream, the status returned shall be the status of the completed trace stream and the status values of the trace stream shall not be reset.

RETURN VALUE
Upon successful completion, these functions shall return a value of zero. Otherwise, they shall return the corresponding error number.

The posix_trace_get_attr() function stores the trace attributes in the object pointed to by attr, if successful.

The posix_trace_get_status() function stores the trace status in the object pointed to by statusinfo, if successful.

ERRORS
These functions shall fail if:

EINVAL
    The trace stream argument trid does not correspond to a valid active trace stream or a valid trace log.

The following sections are informative.

EXAMPLES
None.

APPLICATION USAGE
None.

RATIONALE
None.

FUTURE DIRECTIONS
The posix_trace_get_attr() and posix_trace_get_status() functions may be removed in a future version.

SEE ALSO
posix_trace_attr_destroy(), posix_trace_close(), posix_trace_create()

The Base Definitions volume of POSIX.1-2017, <trace.h>

COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .