PSIGINFO(3)                POSIX Programmer's Manual               PSIGINFO(3)



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

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 .



IEEE/The Open Group                  2017                          PSIGINFO(3)
