1 /* Extended support for using signal values.
2 Written by Fred Fish. fnf@cygnus.com
3 This file is in the public domain. */
9 /* We need to declare sys_siglist, because even if the system provides
10 it we can't assume that it is declared in <signal.h> (for example,
11 SunOS provides sys_siglist, but it does not declare it in any
12 header file). fHowever, we can't declare sys_siglist portably,
13 because on some systems it is declared with const and on some
14 systems it is declared without const. If we were using autoconf,
15 we could work out the right declaration. Until, then we just
16 ignore any declaration in the system header files, and always
17 declare it ourselves. With luck, this will always work. */
18 #define sys_siglist no_such_symbol
19 #define sys_nsig sys_nsig__no_such_symbol
24 /* Routines imported from standard C runtime libraries. */
38 /* Undefine the macro we used to hide the definition of sys_siglist
39 found in the system header files. */
44 # define NULL (void *) 0
48 # define MAX(a,b) ((a) > (b) ? (a) : (b))
51 static void init_signal_tables (void);
53 /* Translation table for signal values.
55 Note that this table is generally only accessed when it is used at runtime
56 to initialize signal name and message tables that are indexed by signal
59 Not all of these signals will exist on all systems. This table is the only
60 thing that should have to be updated as new signal numbers are introduced.
61 It's sort of ugly, but at least its portable. */
65 const int value
; /* The numeric value from <signal.h> */
66 const char *const name
; /* The equivalent symbolic value */
67 #ifndef HAVE_SYS_SIGLIST
68 const char *const msg
; /* Short message about this value */
72 #ifndef HAVE_SYS_SIGLIST
73 # define ENTRY(value, name, msg) {value, name, msg}
75 # define ENTRY(value, name, msg) {value, name}
78 static const struct signal_info signal_table
[] =
81 ENTRY(SIGHUP
, "SIGHUP", "Hangup"),
84 ENTRY(SIGINT
, "SIGINT", "Interrupt"),
87 ENTRY(SIGQUIT
, "SIGQUIT", "Quit"),
90 ENTRY(SIGILL
, "SIGILL", "Illegal instruction"),
93 ENTRY(SIGTRAP
, "SIGTRAP", "Trace/breakpoint trap"),
95 /* Put SIGIOT before SIGABRT, so that if SIGIOT==SIGABRT then SIGABRT
96 overrides SIGIOT. SIGABRT is in ANSI and POSIX.1, and SIGIOT isn't. */
98 ENTRY(SIGIOT
, "SIGIOT", "IOT trap"),
100 #if defined (SIGABRT)
101 ENTRY(SIGABRT
, "SIGABRT", "Aborted"),
104 ENTRY(SIGEMT
, "SIGEMT", "Emulation trap"),
107 ENTRY(SIGFPE
, "SIGFPE", "Arithmetic exception"),
109 #if defined (SIGKILL)
110 ENTRY(SIGKILL
, "SIGKILL", "Killed"),
113 ENTRY(SIGBUS
, "SIGBUS", "Bus error"),
115 #if defined (SIGSEGV)
116 ENTRY(SIGSEGV
, "SIGSEGV", "Segmentation fault"),
119 ENTRY(SIGSYS
, "SIGSYS", "Bad system call"),
121 #if defined (SIGPIPE)
122 ENTRY(SIGPIPE
, "SIGPIPE", "Broken pipe"),
124 #if defined (SIGALRM)
125 ENTRY(SIGALRM
, "SIGALRM", "Alarm clock"),
127 #if defined (SIGTERM)
128 ENTRY(SIGTERM
, "SIGTERM", "Terminated"),
130 #if defined (SIGUSR1)
131 ENTRY(SIGUSR1
, "SIGUSR1", "User defined signal 1"),
133 #if defined (SIGUSR2)
134 ENTRY(SIGUSR2
, "SIGUSR2", "User defined signal 2"),
136 /* Put SIGCLD before SIGCHLD, so that if SIGCLD==SIGCHLD then SIGCHLD
137 overrides SIGCLD. SIGCHLD is in POXIX.1 */
139 ENTRY(SIGCLD
, "SIGCLD", "Child status changed"),
141 #if defined (SIGCHLD)
142 ENTRY(SIGCHLD
, "SIGCHLD", "Child status changed"),
145 ENTRY(SIGPWR
, "SIGPWR", "Power fail/restart"),
147 #if defined (SIGWINCH)
148 ENTRY(SIGWINCH
, "SIGWINCH", "Window size changed"),
151 ENTRY(SIGURG
, "SIGURG", "Urgent I/O condition"),
154 /* "I/O pending" has also been suggested, but is misleading since the
155 signal only happens when the process has asked for it, not everytime
157 ENTRY(SIGIO
, "SIGIO", "I/O possible"),
159 #if defined (SIGPOLL)
160 ENTRY(SIGPOLL
, "SIGPOLL", "Pollable event occurred"),
162 #if defined (SIGSTOP)
163 ENTRY(SIGSTOP
, "SIGSTOP", "Stopped (signal)"),
165 #if defined (SIGTSTP)
166 ENTRY(SIGTSTP
, "SIGTSTP", "Stopped (user)"),
168 #if defined (SIGCONT)
169 ENTRY(SIGCONT
, "SIGCONT", "Continued"),
171 #if defined (SIGTTIN)
172 ENTRY(SIGTTIN
, "SIGTTIN", "Stopped (tty input)"),
174 #if defined (SIGTTOU)
175 ENTRY(SIGTTOU
, "SIGTTOU", "Stopped (tty output)"),
177 #if defined (SIGVTALRM)
178 ENTRY(SIGVTALRM
, "SIGVTALRM", "Virtual timer expired"),
180 #if defined (SIGPROF)
181 ENTRY(SIGPROF
, "SIGPROF", "Profiling timer expired"),
183 #if defined (SIGXCPU)
184 ENTRY(SIGXCPU
, "SIGXCPU", "CPU time limit exceeded"),
186 #if defined (SIGXFSZ)
187 ENTRY(SIGXFSZ
, "SIGXFSZ", "File size limit exceeded"),
189 #if defined (SIGWIND)
190 ENTRY(SIGWIND
, "SIGWIND", "SIGWIND"),
192 #if defined (SIGPHONE)
193 ENTRY(SIGPHONE
, "SIGPHONE", "SIGPHONE"),
195 #if defined (SIGLOST)
196 ENTRY(SIGLOST
, "SIGLOST", "Resource lost"),
198 #if defined (SIGWAITING)
199 ENTRY(SIGWAITING
, "SIGWAITING", "Process's LWPs are blocked"),
202 ENTRY(SIGLWP
, "SIGLWP", "Signal LWP"),
204 #if defined (SIGDANGER)
205 ENTRY(SIGDANGER
, "SIGDANGER", "Swap space dangerously low"),
207 #if defined (SIGGRANT)
208 ENTRY(SIGGRANT
, "SIGGRANT", "Monitor mode granted"),
210 #if defined (SIGRETRACT)
211 ENTRY(SIGRETRACT
, "SIGRETRACT", "Need to relinguish monitor mode"),
214 ENTRY(SIGMSG
, "SIGMSG", "Monitor mode data available"),
216 #if defined (SIGSOUND)
217 ENTRY(SIGSOUND
, "SIGSOUND", "Sound completed"),
220 ENTRY(SIGSAK
, "SIGSAK", "Secure attention"),
225 /* Translation table allocated and initialized at runtime. Indexed by the
226 signal value to find the equivalent symbolic value. */
228 static const char **signal_names
;
229 static int num_signal_names
= 0;
231 /* Translation table allocated and initialized at runtime, if it does not
232 already exist in the host environment. Indexed by the signal value to find
233 the descriptive string.
235 We don't export it for use in other modules because even though it has the
236 same name, it differs from other implementations in that it is dynamically
237 initialized rather than statically initialized. */
239 #ifndef HAVE_SYS_SIGLIST
242 static const char **sys_siglist
;
247 static int sys_nsig
= NSIG
;
250 static int sys_nsig
= _NSIG
;
253 extern const char * const sys_siglist
[];
262 init_signal_tables -- initialize the name and message tables
266 static void init_signal_tables ();
270 Using the signal_table, which is initialized at compile time, generate
271 the signal_names and the sys_siglist (if needed) tables, which are
272 indexed at runtime by a specific signal value.
276 The initialization of the tables may fail under low memory conditions,
277 in which case we don't do anything particularly useful, but we don't
278 bomb either. Who knows, it might succeed at a later point if we free
279 some memory in the meantime. In any case, the other routines know
280 how to deal with lack of a table after trying to initialize it. This
281 may or may not be considered to be a bug, that we don't specifically
282 warn about this particular failure mode.
287 init_signal_tables (void)
289 const struct signal_info
*eip
;
292 /* If we haven't already scanned the signal_table once to find the maximum
293 signal value, then go find it now. */
295 if (num_signal_names
== 0)
297 for (eip
= signal_table
; eip
-> name
!= NULL
; eip
++)
299 if (eip
-> value
>= num_signal_names
)
301 num_signal_names
= eip
-> value
+ 1;
306 /* Now attempt to allocate the signal_names table, zero it out, and then
307 initialize it from the statically initialized signal_table. */
309 if (signal_names
== NULL
)
311 nbytes
= num_signal_names
* sizeof (char *);
312 if ((signal_names
= (const char **) malloc (nbytes
)) != NULL
)
314 memset (signal_names
, 0, nbytes
);
315 for (eip
= signal_table
; eip
-> name
!= NULL
; eip
++)
317 signal_names
[eip
-> value
] = eip
-> name
;
322 #ifndef HAVE_SYS_SIGLIST
324 /* Now attempt to allocate the sys_siglist table, zero it out, and then
325 initialize it from the statically initialized signal_table. */
327 if (sys_siglist
== NULL
)
329 nbytes
= num_signal_names
* sizeof (char *);
330 if ((sys_siglist
= (const char **) malloc (nbytes
)) != NULL
)
332 memset (sys_siglist
, 0, nbytes
);
333 sys_nsig
= num_signal_names
;
334 for (eip
= signal_table
; eip
-> name
!= NULL
; eip
++)
336 sys_siglist
[eip
-> value
] = eip
-> msg
;
348 @deftypefn Extension int signo_max (void)
350 Returns the maximum signal value for which a corresponding symbolic
351 name or message is available. Note that in the case where we use the
352 @code{sys_siglist} supplied by the system, it is possible for there to
353 be more symbolic names than messages, or vice versa. In fact, the
354 manual page for @code{psignal(3b)} explicitly warns that one should
355 check the size of the table (@code{NSIG}) before indexing it, since
356 new signal codes may be added to the system before they are added to
357 the table. Thus @code{NSIG} might be smaller than value implied by
358 the largest signo value defined in @code{<signal.h>}.
360 We return the maximum value that can be used to obtain a meaningful
361 symbolic name or message.
372 if (signal_names
== NULL
)
374 init_signal_tables ();
376 maxsize
= MAX (sys_nsig
, num_signal_names
);
377 return (maxsize
- 1);
383 @deftypefn Supplemental {const char *} strsignal (int @var{signo})
385 Maps an signal number to an signal message string, the contents of
386 which are implementation defined. On systems which have the external
387 variable @code{sys_siglist}, these strings will be the same as the
388 ones used by @code{psignal()}.
390 If the supplied signal number is within the valid range of indices for
391 the @code{sys_siglist}, but no message is available for the particular
392 signal number, then returns the string @samp{Signal @var{num}}, where
393 @var{num} is the signal number.
395 If the supplied signal number is not a valid index into
396 @code{sys_siglist}, returns @code{NULL}.
398 The returned string is only guaranteed to be valid only until the next
399 call to @code{strsignal}.
405 #ifndef HAVE_STRSIGNAL
408 strsignal (int signo
)
413 #ifndef HAVE_SYS_SIGLIST
415 if (signal_names
== NULL
)
417 init_signal_tables ();
422 if ((signo
< 0) || (signo
>= sys_nsig
))
424 /* Out of range, just return NULL */
427 else if ((sys_siglist
== NULL
) || (sys_siglist
[signo
] == NULL
))
429 /* In range, but no sys_siglist or no entry at this index. */
430 sprintf (buf
, "Signal %d", signo
);
431 msg
= (const char *) buf
;
435 /* In range, and a valid message. Just return the message. */
436 msg
= (const char *) sys_siglist
[signo
];
442 #endif /* ! HAVE_STRSIGNAL */
446 @deftypefn Extension {const char*} strsigno (int @var{signo})
448 Given an signal number, returns a pointer to a string containing the
449 symbolic name of that signal number, as found in @code{<signal.h>}.
451 If the supplied signal number is within the valid range of indices for
452 symbolic names, but no name is available for the particular signal
453 number, then returns the string @samp{Signal @var{num}}, where
454 @var{num} is the signal number.
456 If the supplied signal number is not within the range of valid
457 indices, then returns @code{NULL}.
459 The contents of the location pointed to are only guaranteed to be
460 valid until the next call to @code{strsigno}.
472 if (signal_names
== NULL
)
474 init_signal_tables ();
477 if ((signo
< 0) || (signo
>= num_signal_names
))
479 /* Out of range, just return NULL */
482 else if ((signal_names
== NULL
) || (signal_names
[signo
] == NULL
))
484 /* In range, but no signal_names or no entry at this index. */
485 sprintf (buf
, "Signal %d", signo
);
486 name
= (const char *) buf
;
490 /* In range, and a valid name. Just return the name. */
491 name
= signal_names
[signo
];
500 @deftypefn Extension int strtosigno (const char *@var{name})
502 Given the symbolic name of a signal, map it to a signal number. If no
503 translation is found, returns 0.
510 strtosigno (const char *name
)
516 if (signal_names
== NULL
)
518 init_signal_tables ();
520 for (signo
= 0; signo
< num_signal_names
; signo
++)
522 if ((signal_names
[signo
] != NULL
) &&
523 (strcmp (name
, signal_names
[signo
]) == 0))
528 if (signo
== num_signal_names
)
539 @deftypefn Supplemental void psignal (unsigned @var{signo}, char *@var{message})
541 Print @var{message} to the standard error, followed by a colon,
542 followed by the description of the signal specified by @var{signo},
543 followed by a newline.
552 psignal (unsigned signo
, char *message
)
554 if (signal_names
== NULL
)
556 init_signal_tables ();
558 if ((signo
<= 0) || (signo
>= sys_nsig
))
560 fprintf (stderr
, "%s: unknown signal\n", message
);
564 fprintf (stderr
, "%s: %s\n", message
, sys_siglist
[signo
]);
568 #endif /* ! HAVE_PSIGNAL */
571 /* A simple little main that does nothing but print all the signal translations
572 if MAIN is defined and this file is compiled and linked. */
586 maxsigno
= signo_max ();
587 printf ("%d entries in names table.\n", num_signal_names
);
588 printf ("%d entries in messages table.\n", sys_nsig
);
589 printf ("%d is max useful index.\n", maxsigno
);
591 /* Keep printing values until we get to the end of *both* tables, not
592 *either* table. Note that knowing the maximum useful index does *not*
593 relieve us of the responsibility of testing the return pointer for
596 for (signo
= 0; signo
<= maxsigno
; signo
++)
598 name
= strsigno (signo
);
599 name
= (name
== NULL
) ? "<NULL>" : name
;
600 msg
= strsignal (signo
);
601 msg
= (msg
== NULL
) ? "<NULL>" : msg
;
602 printf ("%-4d%-18s%s\n", signo
, name
, msg
);
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