610 lines
15 KiB
C
610 lines
15 KiB
C
/* Extended support for using signal values.
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Written by Fred Fish. fnf@cygnus.com
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This file is in the public domain. */
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#include "config.h"
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#include "ansidecl.h"
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#include "libiberty.h"
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/* We need to declare sys_siglist, because even if the system provides
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it we can't assume that it is declared in <signal.h> (for example,
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SunOS provides sys_siglist, but it does not declare it in any
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header file). However, we can't declare sys_siglist portably,
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because on some systems it is declared with const and on some
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systems it is declared without const. If we were using autoconf,
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we could work out the right declaration. Until, then we just
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ignore any declaration in the system header files, and always
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declare it ourselves. With luck, this will always work. */
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#define sys_siglist no_such_symbol
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#define sys_nsig sys_nsig__no_such_symbol
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#include <stdio.h>
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#include <signal.h>
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/* Routines imported from standard C runtime libraries. */
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#ifdef HAVE_STDLIB_H
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#include <stdlib.h>
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#else
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extern void *malloc ();
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#endif
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#ifdef HAVE_STRING_H
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#include <string.h>
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#else
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extern void *memset ();
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#endif
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/* Undefine the macro we used to hide the definition of sys_siglist
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found in the system header files. */
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#undef sys_siglist
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#undef sys_nsig
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#ifndef NULL
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# define NULL (void *) 0
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#endif
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#ifndef MAX
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# define MAX(a,b) ((a) > (b) ? (a) : (b))
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#endif
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static void init_signal_tables (void);
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/* Translation table for signal values.
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Note that this table is generally only accessed when it is used at runtime
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to initialize signal name and message tables that are indexed by signal
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value.
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Not all of these signals will exist on all systems. This table is the only
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thing that should have to be updated as new signal numbers are introduced.
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It's sort of ugly, but at least its portable. */
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struct signal_info
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{
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const int value; /* The numeric value from <signal.h> */
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const char *const name; /* The equivalent symbolic value */
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#ifndef HAVE_SYS_SIGLIST
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const char *const msg; /* Short message about this value */
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#endif
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};
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#ifndef HAVE_SYS_SIGLIST
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# define ENTRY(value, name, msg) {value, name, msg}
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#else
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# define ENTRY(value, name, msg) {value, name}
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#endif
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static const struct signal_info signal_table[] =
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{
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#if defined (SIGHUP)
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ENTRY(SIGHUP, "SIGHUP", "Hangup"),
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#endif
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#if defined (SIGINT)
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ENTRY(SIGINT, "SIGINT", "Interrupt"),
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#endif
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#if defined (SIGQUIT)
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ENTRY(SIGQUIT, "SIGQUIT", "Quit"),
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#endif
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#if defined (SIGILL)
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ENTRY(SIGILL, "SIGILL", "Illegal instruction"),
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#endif
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#if defined (SIGTRAP)
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ENTRY(SIGTRAP, "SIGTRAP", "Trace/breakpoint trap"),
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#endif
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/* Put SIGIOT before SIGABRT, so that if SIGIOT==SIGABRT then SIGABRT
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overrides SIGIOT. SIGABRT is in ANSI and POSIX.1, and SIGIOT isn't. */
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#if defined (SIGIOT)
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ENTRY(SIGIOT, "SIGIOT", "IOT trap"),
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#endif
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#if defined (SIGABRT)
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ENTRY(SIGABRT, "SIGABRT", "Aborted"),
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#endif
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#if defined (SIGEMT)
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ENTRY(SIGEMT, "SIGEMT", "Emulation trap"),
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#endif
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#if defined (SIGFPE)
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ENTRY(SIGFPE, "SIGFPE", "Arithmetic exception"),
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#endif
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#if defined (SIGKILL)
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ENTRY(SIGKILL, "SIGKILL", "Killed"),
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#endif
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#if defined (SIGBUS)
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ENTRY(SIGBUS, "SIGBUS", "Bus error"),
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#endif
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#if defined (SIGSEGV)
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ENTRY(SIGSEGV, "SIGSEGV", "Segmentation fault"),
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#endif
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#if defined (SIGSYS)
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ENTRY(SIGSYS, "SIGSYS", "Bad system call"),
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#endif
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#if defined (SIGPIPE)
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ENTRY(SIGPIPE, "SIGPIPE", "Broken pipe"),
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#endif
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#if defined (SIGALRM)
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ENTRY(SIGALRM, "SIGALRM", "Alarm clock"),
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#endif
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#if defined (SIGTERM)
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ENTRY(SIGTERM, "SIGTERM", "Terminated"),
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#endif
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#if defined (SIGUSR1)
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ENTRY(SIGUSR1, "SIGUSR1", "User defined signal 1"),
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#endif
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#if defined (SIGUSR2)
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ENTRY(SIGUSR2, "SIGUSR2", "User defined signal 2"),
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#endif
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/* Put SIGCLD before SIGCHLD, so that if SIGCLD==SIGCHLD then SIGCHLD
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overrides SIGCLD. SIGCHLD is in POXIX.1 */
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#if defined (SIGCLD)
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ENTRY(SIGCLD, "SIGCLD", "Child status changed"),
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#endif
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#if defined (SIGCHLD)
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ENTRY(SIGCHLD, "SIGCHLD", "Child status changed"),
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#endif
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#if defined (SIGPWR)
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ENTRY(SIGPWR, "SIGPWR", "Power fail/restart"),
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#endif
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#if defined (SIGWINCH)
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ENTRY(SIGWINCH, "SIGWINCH", "Window size changed"),
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#endif
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#if defined (SIGURG)
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ENTRY(SIGURG, "SIGURG", "Urgent I/O condition"),
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#endif
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#if defined (SIGIO)
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/* "I/O pending" has also been suggested, but is misleading since the
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signal only happens when the process has asked for it, not everytime
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I/O is pending. */
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ENTRY(SIGIO, "SIGIO", "I/O possible"),
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#endif
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#if defined (SIGPOLL)
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ENTRY(SIGPOLL, "SIGPOLL", "Pollable event occurred"),
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#endif
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#if defined (SIGSTOP)
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ENTRY(SIGSTOP, "SIGSTOP", "Stopped (signal)"),
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#endif
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#if defined (SIGTSTP)
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ENTRY(SIGTSTP, "SIGTSTP", "Stopped (user)"),
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#endif
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#if defined (SIGCONT)
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ENTRY(SIGCONT, "SIGCONT", "Continued"),
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#endif
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#if defined (SIGTTIN)
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ENTRY(SIGTTIN, "SIGTTIN", "Stopped (tty input)"),
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#endif
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#if defined (SIGTTOU)
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ENTRY(SIGTTOU, "SIGTTOU", "Stopped (tty output)"),
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#endif
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#if defined (SIGVTALRM)
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ENTRY(SIGVTALRM, "SIGVTALRM", "Virtual timer expired"),
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#endif
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#if defined (SIGPROF)
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ENTRY(SIGPROF, "SIGPROF", "Profiling timer expired"),
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#endif
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#if defined (SIGXCPU)
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ENTRY(SIGXCPU, "SIGXCPU", "CPU time limit exceeded"),
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#endif
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#if defined (SIGXFSZ)
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ENTRY(SIGXFSZ, "SIGXFSZ", "File size limit exceeded"),
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#endif
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#if defined (SIGWIND)
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ENTRY(SIGWIND, "SIGWIND", "SIGWIND"),
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#endif
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#if defined (SIGPHONE)
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ENTRY(SIGPHONE, "SIGPHONE", "SIGPHONE"),
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#endif
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#if defined (SIGLOST)
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ENTRY(SIGLOST, "SIGLOST", "Resource lost"),
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#endif
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#if defined (SIGWAITING)
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ENTRY(SIGWAITING, "SIGWAITING", "Process's LWPs are blocked"),
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#endif
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#if defined (SIGLWP)
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ENTRY(SIGLWP, "SIGLWP", "Signal LWP"),
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#endif
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#if defined (SIGDANGER)
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ENTRY(SIGDANGER, "SIGDANGER", "Swap space dangerously low"),
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#endif
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#if defined (SIGGRANT)
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ENTRY(SIGGRANT, "SIGGRANT", "Monitor mode granted"),
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#endif
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#if defined (SIGRETRACT)
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ENTRY(SIGRETRACT, "SIGRETRACT", "Need to relinguish monitor mode"),
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#endif
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#if defined (SIGMSG)
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ENTRY(SIGMSG, "SIGMSG", "Monitor mode data available"),
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#endif
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#if defined (SIGSOUND)
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ENTRY(SIGSOUND, "SIGSOUND", "Sound completed"),
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#endif
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#if defined (SIGSAK)
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ENTRY(SIGSAK, "SIGSAK", "Secure attention"),
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#endif
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ENTRY(0, NULL, NULL)
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};
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/* Translation table allocated and initialized at runtime. Indexed by the
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signal value to find the equivalent symbolic value. */
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static const char **signal_names;
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static int num_signal_names = 0;
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/* Translation table allocated and initialized at runtime, if it does not
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already exist in the host environment. Indexed by the signal value to find
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the descriptive string.
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We don't export it for use in other modules because even though it has the
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same name, it differs from other implementations in that it is dynamically
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initialized rather than statically initialized. */
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#ifndef HAVE_SYS_SIGLIST
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static int sys_nsig;
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static const char **sys_siglist;
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#else
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#ifdef NSIG
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static int sys_nsig = NSIG;
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#else
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#ifdef _NSIG
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static int sys_nsig = _NSIG;
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#endif
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#endif
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extern const char * const sys_siglist[];
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#endif
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/*
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NAME
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init_signal_tables -- initialize the name and message tables
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SYNOPSIS
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static void init_signal_tables ();
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DESCRIPTION
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Using the signal_table, which is initialized at compile time, generate
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the signal_names and the sys_siglist (if needed) tables, which are
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indexed at runtime by a specific signal value.
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BUGS
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The initialization of the tables may fail under low memory conditions,
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in which case we don't do anything particularly useful, but we don't
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bomb either. Who knows, it might succeed at a later point if we free
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some memory in the meantime. In any case, the other routines know
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how to deal with lack of a table after trying to initialize it. This
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may or may not be considered to be a bug, that we don't specifically
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warn about this particular failure mode.
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*/
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static void
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init_signal_tables (void)
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{
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const struct signal_info *eip;
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int nbytes;
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/* If we haven't already scanned the signal_table once to find the maximum
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signal value, then go find it now. */
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if (num_signal_names == 0)
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{
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for (eip = signal_table; eip -> name != NULL; eip++)
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{
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if (eip -> value >= num_signal_names)
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{
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num_signal_names = eip -> value + 1;
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}
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}
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}
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/* Now attempt to allocate the signal_names table, zero it out, and then
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initialize it from the statically initialized signal_table. */
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if (signal_names == NULL)
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{
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nbytes = num_signal_names * sizeof (char *);
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if ((signal_names = (const char **) malloc (nbytes)) != NULL)
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{
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memset (signal_names, 0, nbytes);
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for (eip = signal_table; eip -> name != NULL; eip++)
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{
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signal_names[eip -> value] = eip -> name;
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}
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}
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}
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#ifndef HAVE_SYS_SIGLIST
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/* Now attempt to allocate the sys_siglist table, zero it out, and then
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initialize it from the statically initialized signal_table. */
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if (sys_siglist == NULL)
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{
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nbytes = num_signal_names * sizeof (char *);
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if ((sys_siglist = (const char **) malloc (nbytes)) != NULL)
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{
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memset (sys_siglist, 0, nbytes);
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sys_nsig = num_signal_names;
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for (eip = signal_table; eip -> name != NULL; eip++)
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{
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sys_siglist[eip -> value] = eip -> msg;
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}
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}
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}
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#endif
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}
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/*
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@deftypefn Extension int signo_max (void)
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Returns the maximum signal value for which a corresponding symbolic
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name or message is available. Note that in the case where we use the
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@code{sys_siglist} supplied by the system, it is possible for there to
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be more symbolic names than messages, or vice versa. In fact, the
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manual page for @code{psignal(3b)} explicitly warns that one should
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check the size of the table (@code{NSIG}) before indexing it, since
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new signal codes may be added to the system before they are added to
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the table. Thus @code{NSIG} might be smaller than value implied by
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the largest signo value defined in @code{<signal.h>}.
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We return the maximum value that can be used to obtain a meaningful
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symbolic name or message.
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@end deftypefn
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*/
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int
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signo_max (void)
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{
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int maxsize;
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if (signal_names == NULL)
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{
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init_signal_tables ();
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}
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maxsize = MAX (sys_nsig, num_signal_names);
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return (maxsize - 1);
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}
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/*
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@deftypefn Supplemental {const char *} strsignal (int @var{signo})
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Maps an signal number to an signal message string, the contents of
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which are implementation defined. On systems which have the external
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variable @code{sys_siglist}, these strings will be the same as the
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ones used by @code{psignal()}.
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If the supplied signal number is within the valid range of indices for
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the @code{sys_siglist}, but no message is available for the particular
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signal number, then returns the string @samp{Signal @var{num}}, where
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@var{num} is the signal number.
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If the supplied signal number is not a valid index into
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@code{sys_siglist}, returns @code{NULL}.
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The returned string is only guaranteed to be valid only until the next
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call to @code{strsignal}.
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@end deftypefn
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*/
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#ifndef HAVE_STRSIGNAL
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char *
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strsignal (int signo)
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{
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char *msg;
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static char buf[32];
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#ifndef HAVE_SYS_SIGLIST
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if (signal_names == NULL)
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{
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init_signal_tables ();
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}
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#endif
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if ((signo < 0) || (signo >= sys_nsig))
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{
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/* Out of range, just return NULL */
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msg = NULL;
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}
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else if ((sys_siglist == NULL) || (sys_siglist[signo] == NULL))
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{
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/* In range, but no sys_siglist or no entry at this index. */
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sprintf (buf, "Signal %d", signo);
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msg = buf;
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}
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else
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{
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/* In range, and a valid message. Just return the message. We
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can safely cast away const, since POSIX says the user must
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not modify the result. */
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msg = (char *) sys_siglist[signo];
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}
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return (msg);
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}
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#endif /* ! HAVE_STRSIGNAL */
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/*
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@deftypefn Extension {const char*} strsigno (int @var{signo})
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Given an signal number, returns a pointer to a string containing the
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symbolic name of that signal number, as found in @code{<signal.h>}.
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If the supplied signal number is within the valid range of indices for
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symbolic names, but no name is available for the particular signal
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number, then returns the string @samp{Signal @var{num}}, where
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@var{num} is the signal number.
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If the supplied signal number is not within the range of valid
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indices, then returns @code{NULL}.
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The contents of the location pointed to are only guaranteed to be
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valid until the next call to @code{strsigno}.
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@end deftypefn
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*/
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const char *
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strsigno (int signo)
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{
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const char *name;
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static char buf[32];
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if (signal_names == NULL)
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{
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init_signal_tables ();
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}
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if ((signo < 0) || (signo >= num_signal_names))
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{
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/* Out of range, just return NULL */
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name = NULL;
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}
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else if ((signal_names == NULL) || (signal_names[signo] == NULL))
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{
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/* In range, but no signal_names or no entry at this index. */
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sprintf (buf, "Signal %d", signo);
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name = (const char *) buf;
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}
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else
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{
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/* In range, and a valid name. Just return the name. */
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name = signal_names[signo];
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}
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return (name);
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}
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/*
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@deftypefn Extension int strtosigno (const char *@var{name})
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Given the symbolic name of a signal, map it to a signal number. If no
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translation is found, returns 0.
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@end deftypefn
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*/
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int
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strtosigno (const char *name)
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{
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int signo = 0;
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if (name != NULL)
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{
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if (signal_names == NULL)
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{
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init_signal_tables ();
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}
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for (signo = 0; signo < num_signal_names; signo++)
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{
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if ((signal_names[signo] != NULL) &&
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(strcmp (name, signal_names[signo]) == 0))
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{
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break;
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}
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}
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if (signo == num_signal_names)
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{
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signo = 0;
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}
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}
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return (signo);
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}
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/*
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@deftypefn Supplemental void psignal (int @var{signo}, char *@var{message})
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Print @var{message} to the standard error, followed by a colon,
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followed by the description of the signal specified by @var{signo},
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followed by a newline.
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@end deftypefn
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*/
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#ifndef HAVE_PSIGNAL
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void
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psignal (int signo, char *message)
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{
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if (signal_names == NULL)
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{
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init_signal_tables ();
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}
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if ((signo <= 0) || (signo >= sys_nsig))
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{
|
|
fprintf (stderr, "%s: unknown signal\n", message);
|
|
}
|
|
else
|
|
{
|
|
fprintf (stderr, "%s: %s\n", message, sys_siglist[signo]);
|
|
}
|
|
}
|
|
|
|
#endif /* ! HAVE_PSIGNAL */
|
|
|
|
|
|
/* A simple little main that does nothing but print all the signal translations
|
|
if MAIN is defined and this file is compiled and linked. */
|
|
|
|
#ifdef MAIN
|
|
|
|
#include <stdio.h>
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
int signo;
|
|
int maxsigno;
|
|
const char *name;
|
|
const char *msg;
|
|
|
|
maxsigno = signo_max ();
|
|
printf ("%d entries in names table.\n", num_signal_names);
|
|
printf ("%d entries in messages table.\n", sys_nsig);
|
|
printf ("%d is max useful index.\n", maxsigno);
|
|
|
|
/* Keep printing values until we get to the end of *both* tables, not
|
|
*either* table. Note that knowing the maximum useful index does *not*
|
|
relieve us of the responsibility of testing the return pointer for
|
|
NULL. */
|
|
|
|
for (signo = 0; signo <= maxsigno; signo++)
|
|
{
|
|
name = strsigno (signo);
|
|
name = (name == NULL) ? "<NULL>" : name;
|
|
msg = strsignal (signo);
|
|
msg = (msg == NULL) ? "<NULL>" : msg;
|
|
printf ("%-4d%-18s%s\n", signo, name, msg);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif
|