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.
— retrieve and set the behavior of a trace stream (TRACING)
int posix_trace_attr_getinherited(const trace_attr_t *restrict attr,
int *restrict inheritancepolicy);
int posix_trace_attr_getlogfullpolicy(const trace_attr_t *restrict attr,
int *restrict logpolicy);
int posix_trace_attr_getstreamfullpolicy(const trace_attr_t *restrict
attr, int *restrict streampolicy);
int posix_trace_attr_setinherited(trace_attr_t *attr,
int posix_trace_attr_setlogfullpolicy(trace_attr_t *attr,
int posix_trace_attr_setstreamfullpolicy(trace_attr_t *attr,
The posix_trace_attr_getinherited() and posix_trace_attr_setinherited()
functions, respectively, shall get and set the inheritance policy
stored in the inheritance attribute for traced processes across the
fork() and spawn() operations. The inheritance attribute of the
attributes object pointed to by the attr argument shall be set to one
of the following values defined by manifest constants in the <trace.h>
After a fork() or spawn() operation, the child shall not be
traced, and tracing of the parent shall continue.
After a fork() or spawn() operation, if the parent is being
traced, its child shall be concurrently traced using the same
The default value for the inheritance attribute is
The posix_trace_attr_getlogfullpolicy() and posix_trace_attr_setlog‐
fullpolicy() functions, respectively, shall get and set the trace log
full policy stored in the log-full-policy attribute of the attributes
object pointed to by the attr argument.
The log-full-policy attribute shall be set to one of the following val‐
ues defined by manifest constants in the <trace.h> header:
The trace log shall loop until the associated trace stream is
stopped. This policy means that when the trace log gets full,
the file system shall reuse the resources allocated to the oldest
trace events that were recorded. In this way, the trace log will
always contain the most recent trace events flushed.
The trace stream shall be flushed to the trace log until the
trace log is full. This condition can be deduced from the
posix_log_full_status member status (see the posix_trace_sta‐
tus_info structure defined in <trace.h>). The last recorded
trace event shall be the POSIX_TRACE_STOP trace event.
The associated trace stream shall be flushed to the trace log
without log size limitation. If the application specifies
POSIX_TRACE_APPEND, the implementation shall ignore the log-max-
The default value for the log-full-policy attribute is
The posix_trace_attr_getstreamfullpolicy() and posix_trace_attr_set‐
streamfullpolicy() functions, respectively, shall get and set the trace
stream full policy stored in the stream-full-policy attribute of the
attributes object pointed to by the attr argument.
The stream-full-policy attribute shall be set to one of the following
values defined by manifest constants in the <trace.h> header:
The trace stream shall loop until explicitly stopped by the
posix_trace_stop() function. This policy means that when the
trace stream is full, the trace system shall reuse the resources
allocated to the oldest trace events recorded. In this way, the
trace stream will always contain the most recent trace events
The trace stream will run until the trace stream resources are
exhausted. Then the trace stream will stop. This condition can be
deduced from posix_stream_status and posix_stream_full_status
(see the posix_trace_status_info structure defined in <trace.h>).
When this trace stream is read, a POSIX_TRACE_STOP trace event
shall be reported after reporting the last recorded trace event.
The trace system shall reuse the resources allocated to any trace
events already reported—see the posix_trace_getnext_event(),
posix_trace_trygetnext_event(), and posix_trace_timedget‐
next_event() functions—or already flushed for an active trace
stream with log if the Trace Log option is supported; see the
posix_trace_flush() function. The trace system shall restart the
trace stream when it is empty and may restart it sooner. A
POSIX_TRACE_START trace event shall be reported before reporting
the next recorded trace event.
If the Trace Log option is supported, this policy is identical to
the POSIX_TRACE_UNTIL_FULL trace stream full policy except that
the trace stream shall be flushed regularly as if
posix_trace_flush() had been explicitly called. Defining this
policy for an active trace stream without log shall be invalid.
The default value for the stream-full-policy attribute shall be
POSIX_TRACE_LOOP for an active trace stream without log.
If the Trace Log option is supported, the default value for the stream-
full-policy attribute shall be POSIX_TRACE_FLUSH for an active trace
stream with log.
Upon successful completion, these functions shall return a value of
zero. Otherwise, they shall return the corresponding error number.
If successful, the posix_trace_attr_getinherited() function shall store
the inheritance attribute value in the object pointed to by inheritan‐
cepolicy. Otherwise, the content of this object is undefined.
If successful, the posix_trace_attr_getlogfullpolicy() function shall
store the log-full-policy attribute value in the object pointed to by
logpolicy. Otherwise, the content of this object is undefined.
If successful, the posix_trace_attr_getstreamfullpolicy() function
shall store the stream-full-policy attribute value in the object
pointed to by streampolicy. Otherwise, the content of this object is
These functions may fail if:
EINVAL The value specified by at least one of the arguments is invalid.
The following sections are informative.
The following functions:
may be removed in a future version.
SEE ALSOfork(), posix_trace_attr_destroy(), posix_trace_create(),
The Base Definitions volume of POSIX.1‐2008, <trace.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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.ker‐
IEEE/The Open Group 2013 POSIX_TRACE_ATTR_GETINHERITED(3P)