manpagez: man (manual) pages & more
man psignal(3)
Home | html | info | man
psignal(3)               BSD Library Functions Manual               psignal(3)


NAME

     psignal, strsignal, sys_siglist, sys_signame -- system signal messages


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <signal.h>

     void
     psignal(unsigned sig, const char *s);

     extern const char * const sys_siglist[];
     extern const char * const sys_signame[];

     #include <string.h>

     char *
     strsignal(int sig);


DESCRIPTION

     The psignal() and strsignal() functions locate the descriptive message
     string for a signal number.

     The strsignal() function accepts a signal number argument sig and returns
     a pointer to the corresponding message string.

     The psignal() function accepts a signal number argument sig and writes it
     to the standard error.  If the argument s is non-NULL and does not point
     to the null character, s is written to the standard error file descriptor
     prior to the message string, immediately followed by a colon and a space.
     If the signal number is not recognized (sigaction(2)), the string
     ``Unknown signal'' is produced.

     The message strings can be accessed directly through the external array
     sys_siglist, indexed by recognized signal numbers.  The external array
     sys_signame is used similarly and contains short, lower-case abbrevia-
     tions for signals which are useful for recognizing signal names in user
     input.  The defined variable NSIG contains a count of the strings in
     sys_siglist and sys_signame.


RETURN VALUES

     strsignal() a pointer to the desired message or a NULL value indicating
     an error.  This string is not to be freed by the caller.  Beginning with
     Mac OSX 10.7, this string is unique to each thread.


ERRORS

     strsignal() will fail and no additional memory will be allocated if one
     of the following are true:

     [ENOMEM]           There was insufficient memory to allocate storage
                        space for the return value in the running thread.


SEE ALSO

     sigaction(2), perror(3), strerror(3)


HISTORY

     The psignal() function appeared in 4.2BSD.

BSD                            February 27, 1995                           BSD

Mac OS X 10.8 - Generated Wed Aug 29 19:29:49 CDT 2012