PSIGINFO
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
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
psiginfo, psignal
--- write signal information to standard error
SYNOPSIS
#include <signal.h>
void psiginfo(const siginfo_t *pinfo, const char *message);
void psignal(int signum, const char *message);
DESCRIPTION
The
psiginfo()
and
psignal()
functions shall write a language-dependent message associated with a
signal number to the standard error stream as follows:
- *
-
First, if
message
is not a null pointer and is not the empty string, the string pointed
to by the
message
argument shall be written, followed by a
<colon>
and a
<space>.
- *
-
Then the signal description string associated with
signum
or with the signal indicated by
pinfo
shall be written, followed by a
<newline>.
For
psiginfo(),
the application shall ensure that the argument
pinfo
references a valid
siginfo_t
structure. For
psignal(),
if
signum
is not a valid signal number, the behavior is implementation-defined.
The
psiginfo()
and
psignal()
functions shall not change the orientation of the standard error stream.
The
psiginfo()
and
psignal()
functions shall mark for update the last data modification and last file
status change timestamps of the file associated with the standard error
stream at some time between their successful completion and
exit(),
abort(),
or the completion of
fflush()
or
fclose()
on
stderr.
The
psiginfo()
and
psignal()
functions shall not change the setting of
errno
if successful.
On error, the
psiginfo()
and
psignal()
functions shall set the error indicator for the stream to which
stderr
points, and shall set
errno
to indicate the error.
Since no value is returned, an application wishing to check for error
situations should set
errno
to 0, then call
psiginfo()
or
psignal(),
then check
errno.
RETURN VALUE
These functions shall not return a value.
ERRORS
Refer to
fputc().
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
As an alternative to setting
errno
to zero before the call and checking if it is non-zero afterwards,
applications can use
ferror()
to detect whether
psiginfo()
or
psignal()
encountered an error.
An application wishing to use this method to check for error situations
should call
clearerr(stderr)
before calling
psiginfo()
or
psignal(),
then if
ferror(stderr)
returns non-zero, the value of
errno
indicates which error occurred.
RATIONALE
System V historically has
psignal()
and
psiginfo()
in
<siginfo.h>.
However, the
<siginfo.h>
header is not specified in the Base Definitions volume of POSIX.1-2017, and the type
siginfo_t
is defined in
<signal.h>.
FUTURE DIRECTIONS
None.
SEE ALSO
fputc(),
perror(),
strsignal()
The Base Definitions volume of POSIX.1-2017,
<signal.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 .