xref: /freebsd/lib/libc/gen/psignal.3 (revision a0ee8cc6)
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28.\"     @(#)psignal.3	8.2 (Berkeley) 2/27/95
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31.Dd February 4, 2011
32.Dt PSIGNAL 3
33.Os
34.Sh NAME
35.Nm psignal ,
36.Nm strsignal ,
37.Nm sys_siglist ,
38.Nm sys_signame
39.Nd system signal messages
40.Sh LIBRARY
41.Lb libc
42.Sh SYNOPSIS
43.In signal.h
44.Ft void
45.Fn psignal "unsigned sig" "const char *s"
46.Vt extern const char * const sys_siglist[] ;
47.Vt extern const char * const sys_signame[] ;
48.In string.h
49.Ft "char *"
50.Fn strsignal "int sig"
51.Sh DESCRIPTION
52The
53.Fn psignal
54and
55.Fn strsignal
56functions locate the descriptive message
57string for a signal number.
58.Pp
59The
60.Fn strsignal
61function accepts a signal number argument
62.Fa sig
63and returns a pointer to the corresponding message string.
64.Pp
65The
66.Fn psignal
67function accepts a signal number argument
68.Fa sig
69and writes it to the standard error.
70If the argument
71.Fa s
72is
73.Pf non- Dv NULL
74and does not point to the null character,
75.Fa s
76is written to the standard error file descriptor
77prior to the message string,
78immediately followed by a colon and a space.
79If the signal number is not recognized
80.Pq Xr sigaction 2 ,
81the string
82.Dq "Unknown signal"
83is produced.
84.Pp
85The message strings can be accessed directly
86through the external array
87.Va sys_siglist ,
88indexed by recognized signal numbers.
89The external array
90.Va sys_signame
91is used similarly and
92contains short, upper-case abbreviations for signals
93which are useful for recognizing signal names
94in user input.
95The defined variable
96.Dv NSIG
97contains a count of the strings in
98.Va sys_siglist
99and
100.Va sys_signame .
101.Sh SEE ALSO
102.Xr sigaction 2 ,
103.Xr perror 3 ,
104.Xr strerror 3
105.Sh HISTORY
106The
107.Fn psignal
108function appeared in
109.Bx 4.2 .
110