SIGNAL(L)           Linux Programmer's Manual           SIGNAL(L)



NAME
       signal - list of available signals

DESCRIPTION
       Linux  supports  the  signals listed below. Several signal
       numbers are  architecture  dependent.  First  the  signals
       described in POSIX.1.


       l c c l ____ lB c c l.  Signal    Value     Action    Com-
       ment SIGHUP     1   A    Hangup  detected  on  controlling
       terminal                 or  death  of controlling process
       SIGINT     2 A    Interrupt         from          keyboard
       SIGQUIT    3   C    Quit      from      keyboard      SIG-
       ILL     4   C    Illegal         Instruction         SIGA-
       BRT    6   C    Abort       signal      from      abort(t)
       SIGFPE     8   C    Floating        point        exception
       SIGKILL    9   AEF  Kill                            signal
       SIGSEGV   11   C    Invalid    memory    reference    SIG-
       PIPE   13   A    Broken  pipe: write to pipe with no read-
       ers   SIGALRM   14   A    Timer   signal   from   alarm(m)
       SIGTERM   15   A    Termination                     signal
       SIGUSR1   30,10,16  A    User-defined       signal       1
       SIGUSR2   31,12,17  A    User-defined       signal       2
       SIGCHLD   20,17,18  B    Child stopped or terminated  SIG-
       CONT   19,18,25       Continue          if         stopped
       SIGSTOP   17,19,23  DEF  Stop        process         SIGT-
       STP   18,20,24  D    Stop     typed     at    tty    SIGT-
       TIN   21,21,26  D    tty  input  for  background   process
       SIGTTOU   22,22,27  D    tty output for background process

       Next the signals not in POSIX.1 but described in SUSv2.


       l c c l ____ lB c c l.  Signal    Value     Action    Com-
       ment   SIGBUS    10,7,10   C    Bus   error   (bad  memory
       access) SIGPOLL        A    Pollable event (Sys  V).  Syn-
       onym  of  SIGIO  SIGPROF   27,27,29  A    Profiling  timer
       expired SIGSYS    12,-,12   C    Bad argument  to  routine
       (SVID)   SIGTRAP   5    C    Trace/breakpoint   trap  SIG-
       URG    16,23,21  B    Urgent condition on socket (4.2 BSD)
       SIGVTALRM 26,26,28  A    Virtual  alarm  clock  (4.2  BSD)
       SIGXCPU   24,24,30  C    CPU time limit exceeded (4.2 BSD)
       SIGXFSZ   25,25,31  C    File  size  limit  exceeded  (4.2
       BSD)

       (For the cases  SIGSYS,  SIGXCPU,  SIGXFSZ,  and  on  some
       architectures  also SIGBUS, the Linux default action up to
       now (2.3.27) is A (terminate), while  SUSv2  prescribes  C
       (terminate and dump core).)

       Next various other signals.


       l c c l ____ lB c c l.  Signal    Value     Action    Com-
       ment SIGIOT    6    C    IOT trap. A synonym  for  SIGABRT
       SIGEMT    7,-,7       SIGSTKFLT -,16,-    A    Stack fault
       on coprocessor SIGIO     23,29,22  A    I/O  now  possible
       (4.2  BSD)  SIGCLD    -,-,18         A synonym for SIGCHLD
       SIGPWR    29,30,19  A    Power  failure  (System  V)  SIG-
       INFO   29,-,-         A       synonym      for      SIGPWR
       SIGLOST   -,-,-     A    File          lock           lost
       SIGWINCH  28,28,20  B    Window  resize  signal  (4.3 BSD,
       Sun)  SIGUNUSED -,31,-    A    Unused  signal   (will   be
       SIGSYS)

       (Here - denotes that a signal is absent; there where three
       values are given, the first one is usually valid for alpha
       and  sparc,  the  middle  one for i386 and ppc and sh, the
       last one for mips.  Signal 29 is SIGINFO /  SIGPWR  on  an
       alpha but SIGLOST on a sparc.)

       The  letters  in  the  "Action"  column have the following
       meanings:

       A      Default action is to terminate the process.

       B      Default action is to ignore the signal.

       C      Default action is to terminate the process and dump
              core.

       D      Default action is to stop the process.

       E      Signal cannot be caught.

       F      Signal cannot be ignored.

CONFORMING TO
       POSIX.1

BUGS
       SIGIO and SIGLOST have the same value.  The latter is com-
       mented out in the kernel source, but the build process  of
       some software still thinks that signal 29 is SIGLOST.

SEE ALSO
       kill(l), kill(l), setitimer(r)



Linux 1.3.88                1996-04-14                  SIGNAL(L)