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 .

IEEE/The Open Group                                   2017                                      PSIGINFO(3POSIX)