PSIGNAL(3) | Library Functions Manual | PSIGNAL(3) |
psignal
,
strsignal
, strsignal_r
,
sys_siglist
, sys_signame
— system signal messages
Standard C Library (libc, -lc)
#include
<signal.h>
void
psignal
(int
sig, const char
*s);
extern const char * const sys_siglist[];
extern const char * const sys_signame[];
#include
<string.h>
char *
strsignal
(int
sig);
int
strsignal_r
(int sig,
char *strsignalbuf, size_t
buflen);
The
psignal
(),
strsignal
(), and
strsignal_r
() 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
strsignal_r
()
function renders the same result into strsignalbuf for
a maximum of buflen characters and returns 0 upon
success.
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, upper-case abbreviations 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.
The strsignal
() function returns a pointer
to the desired message or NULL
to indicate an error.
This string is not to be freed by the caller. Beginning with Mac OS X 10.7,
this string is unique to each thread.
The strsignal_r
() function returns 0 if
the message string was successfully copied in its entirety to
strsignalbuf.
The strsignal
() function will fail and no
additional memory will be allocated if one of the following are true:
ENOMEM
]The strsignal_r
() function will return an
error (but not fail) if one or more condition is met:
ERANGE
]EINVAL
]The psignal
() function appeared in
4.2BSD.
May 30, 2016 | macOS 14.6 |