[apple/libc.git] / gen / FreeBSD / psignal.3

.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)psignal.3	8.2 (Berkeley) 2/27/95
.\" $FreeBSD: src/lib/libc/gen/psignal.3,v 1.17 2007/01/09 00:27:54 imp Exp $
.\"
.Dd February 27, 1995
.Dt PSIGNAL 3
.Os
.Sh NAME
.Nm psignal ,
.Nm strsignal ,
.Nm strsignal_r ,
.Nm sys_siglist ,
.Nm sys_signame
.Nd system signal messages
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In signal.h
.Ft void
.Fn psignal "unsigned sig" "const char *s"
.Vt extern const char * const sys_siglist[] ;
.Vt extern const char * const sys_signame[] ;
.In string.h
.Ft "char *"
.Fn strsignal "int sig"
.Ft "int"
.Fo strsignal_r
.Fa "int sig"
.Fa "char *strsignalbuf"
.Fa "size_t buflen"
.Fc
.Sh DESCRIPTION
The
.Fn psignal ,
.Fn strsignal ,
and
.Fn strsignal_r
functions locate the descriptive message
string for a signal number.
.Pp
The
.Fn strsignal
function accepts a signal number argument
.Fa sig
and returns a pointer to the corresponding message string.
.Pp
The
.Fn strsignal_r
function renders the same result into
.Fa strsignalbuf
for a maximum of
.Fa buflen
characters and returns 0 upon success.
.Pp
The
.Fn psignal
function accepts a signal number argument
.Fa sig
and writes it to the standard error.
If the argument
.Fa s
is
.Pf non- Dv NULL
and does not point to the null character,
.Fa 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
.Pq Xr sigaction 2 ,
the string
.Dq "Unknown signal
is produced.
.Pp
The message strings can be accessed directly
through the external array
.Va sys_siglist ,
indexed by recognized signal numbers.
The external array
.Va sys_signame
is used similarly and
contains short, lower-case abbreviations for signals
which are useful for recognizing signal names
in user input.
The defined variable
.Dv NSIG
contains a count of the strings in
.Va sys_siglist
and
.Va sys_signame .
.Sh RETURN VALUES
.Fn 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.
.Pp
.Fn strsignal_r
0 if the message string is successfully copied in its entirety to
.Fa strsignalbuf .
.Pp
.Sh ERRORS
.Fn strsignal
will fail and no additional memory will be allocated if
one of the following are true:
.Bl -tag -width Er
.It Bq Er ENOMEM
There was insufficient memory to allocate storage space for the return value in the running thread.
.El
.Pp
.Fn strsignal_r
will return an error (but not fail) if one or more condition is met:
.Bl -tag -width Er
.It Bq Er ERANGE
.Fa buflen
is not long enough to fit the length of the message.
.Fa strsignalbuf 
will contain the message string that has been truncated and
NUL terminated to fit the length specified by
.Fa buflen .
.El
.Bl -tag -width Er
.It Bq Er EINVAL
.Fa sig
<= 0 or >= NSIG.
.El
.Sh SEE ALSO
.Xr sigaction 2 ,
.Xr perror 3 ,
.Xr strerror 3
.Sh HISTORY
The
.Fn psignal
function appeared in
.Bx 4.2 .
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1983, 1991, 1993
e9ce8d39 A	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
e9ce8d39 A	12	.\" 4. Neither the name of the University nor the names of its contributors
	13	.\" may be used to endorse or promote products derived from this software
	14	.\" without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	17	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	18	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	19	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	20	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	21	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	22	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	23	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	24	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	25	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	26	.\" SUCH DAMAGE.
	27	.\"
5b2abdfb	28	.\" @(#)psignal.3 8.2 (Berkeley) 2/27/95
1f2f436a	29	.\" $FreeBSD: src/lib/libc/gen/psignal.3,v 1.17 2007/01/09 00:27:54 imp Exp $
e9ce8d39	30	.\"
5b2abdfb A	31	.Dd February 27, 1995
5b2abdfb A	32	.Dt PSIGNAL 3
e9ce8d39 A	33	.Os
e9ce8d39 A	34	.Sh NAME
5b2abdfb A	35	.Nm psignal ,
5b2abdfb A	36	.Nm strsignal ,
a9aaacca	37	.Nm strsignal_r ,
5b2abdfb A	38	.Nm sys_siglist ,
	39	.Nm sys_signame
	40	.Nd system signal messages
e9ce8d39 A	41	.Sh LIBRARY
	42	.Lb libc
	43	.Sh SYNOPSIS
5b2abdfb A	44	.In signal.h
	45	.Ft void
	46	.Fn psignal "unsigned sig" "const char *s"
	47	.Vt extern const char * const sys_siglist[] ;
	48	.Vt extern const char * const sys_signame[] ;
	49	.In string.h
	50	.Ft "char *"
	51	.Fn strsignal "int sig"
a9aaacca A	52	.Ft "int"
	53	.Fo strsignal_r
	54	.Fa "int sig"
	55	.Fa "char *strsignalbuf"
	56	.Fa "size_t buflen"
	57	.Fc
e9ce8d39 A	58	.Sh DESCRIPTION
e9ce8d39 A	59	The
a9aaacca A	60	.Fn psignal ,
a9aaacca A	61	.Fn strsignal ,
e9ce8d39	62	and
a9aaacca	63	.Fn strsignal_r
5b2abdfb A	64	functions locate the descriptive message
	65	string for a signal number.
	66	.Pp
e9ce8d39	67	The
5b2abdfb A	68	.Fn strsignal
	69	function accepts a signal number argument
	70	.Fa sig
	71	and returns a pointer to the corresponding message string.
	72	.Pp
	73	The
a9aaacca A	74	.Fn strsignal_r
	75	function renders the same result into
	76	.Fa strsignalbuf
	77	for a maximum of
	78	.Fa buflen
	79	characters and returns 0 upon success.
	80	.Pp
	81	The
5b2abdfb	82	.Fn psignal
9385eb3d	83	function accepts a signal number argument
5b2abdfb A	84	.Fa sig
	85	and writes it to the standard error.
	86	If the argument
	87	.Fa s
	88	is
	89	.Pf non- Dv NULL
	90	and does not point to the null character,
	91	.Fa s
	92	is written to the standard error file descriptor
	93	prior to the message string,
	94	immediately followed by a colon and a space.
	95	If the signal number is not recognized
	96	.Pq Xr sigaction 2 ,
	97	the string
	98	.Dq "Unknown signal
	99	is produced.
	100	.Pp
	101	The message strings can be accessed directly
	102	through the external array
	103	.Va sys_siglist ,
	104	indexed by recognized signal numbers.
	105	The external array
	106	.Va sys_signame
	107	is used similarly and
	108	contains short, lower-case abbreviations for signals
	109	which are useful for recognizing signal names
	110	in user input.
	111	The defined variable
	112	.Dv NSIG
	113	contains a count of the strings in
	114	.Va sys_siglist
	115	and
	116	.Va sys_signame .
ad3c9f2a A	117	.Sh RETURN VALUES
	118	.Fn strsignal
	119	a pointer to the desired message or a NULL value indicating an error. This
	120	string is not to be freed by the caller. Beginning with Mac OSX 10.7, this
	121	string is unique to each thread.
a9aaacca A	122	.Pp
	123	.Fn strsignal_r
	124	0 if the message string is successfully copied in its entirety to
	125	.Fa strsignalbuf .
	126	.Pp
ad3c9f2a A	127	.Sh ERRORS
	128	.Fn strsignal
	129	will fail and no additional memory will be allocated if
	130	one of the following are true:
	131	.Bl -tag -width Er
	132	.It Bq Er ENOMEM
	133	There was insufficient memory to allocate storage space for the return value in the running thread.
	134	.El
a9aaacca A	135	.Pp
	136	.Fn strsignal_r
	137	will return an error (but not fail) if one or more condition is met:
	138	.Bl -tag -width Er
	139	.It Bq Er ERANGE
	140	.Fa buflen
	141	is not long enough to fit the length of the message.
	142	.Fa strsignalbuf
	143	will contain the message string that has been truncated and
	144	NUL terminated to fit the length specified by
	145	.Fa buflen .
	146	.El
	147	.Bl -tag -width Er
	148	.It Bq Er EINVAL
	149	.Fa sig
	150	<= 0 or >= NSIG.
	151	.El
e9ce8d39	152	.Sh SEE ALSO
5b2abdfb A	153	.Xr sigaction 2 ,
	154	.Xr perror 3 ,
	155	.Xr strerror 3
e9ce8d39 A	156	.Sh HISTORY
e9ce8d39 A	157	The
5b2abdfb A	158	.Fn psignal
	159	function appeared in
	160	.Bx 4.2 .