Magellan Linux

  • Back to homepage
    • /[magellan-source]/trunk/mkinitrd-magellan/busybox/shell/ash_doc.txt

    Diff of /trunk/mkinitrd-magellan/busybox/shell/ash_doc.txt

    Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

    revision 983 by niro, Fri Apr 24 18:33:46 2009 UTC revision 984 by niro, Sun May 30 11:32:42 2010 UTC
    # Line 14  $ wait Line 14  $ wait
    14  ^C  ^C
    15  ...  ...
    16    
    17    
    18  Bug 1984 (http://busybox.net/bugs/view.php?id=1984):  Bug 1984 (http://busybox.net/bugs/view.php?id=1984):
    19  traps were not triggering:  traps were not triggering:
    20    
    # Line 29  sleep 3600 & Line 30  sleep 3600 &
    30  echo "Please do: kill -USR1 $$"  echo "Please do: kill -USR1 $$"
    31  echo "or: kill -INT $$"  echo "or: kill -INT $$"
    32  while true; do wait; echo wait interrupted; done  while true; do wait; echo wait interrupted; done
    33    
    34    
    35    Bug 189 (https://bugs.busybox.net/show_bug.cgi?id=189)
    36    
    37    func() {
    38        sleep 1
    39    }
    40    while (true); do
    41        func
    42        echo Looping
    43    done
    44    
    45    ^C was observed to make ash processes geometrically multiply (!) instead
    46    of exiting. (true) in subshell does not seem to matter, as another user
    47    reports the same with:
    48    
    49    trap "echo USR1" USR1
    50    while true; do
    51        echo Sleeping
    52        sleep 5
    53    done
    54    
    55    Compat note.
    56    Bash version 3.2.0(1) exits this script at the receipt of SIGINT
    57    _only_ if it had two last children die from it.
    58    The following trace was obtained while periodically running
    59    "killall -SIGINT sleep; sleep 0.1; kill -SIGINT <bash_PID>":
    60    
    61    23:48:32.376707 clone(...) = 13528
    62    23:48:32.388706 waitpid(-1, 0xffc832ec, 0) = ? ERESTARTSYS (To be restarted)
    63    23:48:32.459761 --- SIGINT (Interrupt) @ 0 (0) ---
    64        kill -SIGINT <bash_PID> is ignored, back to waiting:
    65    23:48:32.463706 waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 13528
    66        sleep exited with 0
    67    23:48:37.377557 --- SIGCHLD (Child exited) @ 0 (0) ---
    68    23:48:37.378451 clone(...) = 13538
    69    23:48:37.390708 waitpid(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGINT}], 0) = 13538
    70        sleep was killed by "killall -SIGINT sleep"
    71    23:48:38.523944 --- SIGCHLD (Child exited) @ 0 (0) ---
    72    23:48:38.524861 clone(...) = 13542
    73    23:48:38.538706 waitpid(-1, 0xffc832ec, 0) = ? ERESTARTSYS (To be restarted)
    74    23:48:38.624761 --- SIGINT (Interrupt) @ 0 (0) ---
    75        kill -SIGINT <bash_PID> is ignored, back to waiting:
    76    23:48:38.628706 waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 13542
    77        sleep exited with 0
    78    23:48:43.525674 --- SIGCHLD (Child exited) @ 0 (0) ---
    79    23:48:43.526563 clone(...) = 13545
    80    23:48:43.538709 waitpid(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGINT}], 0) = 13545
    81        sleep was killed by "killall -SIGINT sleep"
    82    23:48:44.466848 --- SIGCHLD (Child exited) @ 0 (0) ---
    83    23:48:44.467735 clone(...) = 13549
    84    23:48:44.481706 waitpid(-1, 0xffc832ec, 0) = ? ERESTARTSYS (To be restarted)
    85    23:48:44.567757 --- SIGINT (Interrupt) @ 0 (0) ---
    86        kill -SIGINT <bash_PID> is ignored, back to waiting:
    87    23:48:44.571706 waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 13549
    88        sleep exited with 0
    89    23:48:49.468553 --- SIGCHLD (Child exited) @ 0 (0) ---
    90    23:48:49.469445 clone(...) = 13551
    91    23:48:49.481708 waitpid(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGINT}], 0) = 13551
    92        sleep was killed by "killall -SIGINT sleep"
    93    23:48:50.515837 --- SIGCHLD (Child exited) @ 0 (0) ---
    94    23:48:50.516718 clone(...) = 13555
    95    23:48:50.530706 waitpid(-1, 0xffc832ec, 0) = ? ERESTARTSYS (To be restarted)
    96    23:48:50.615761 --- SIGINT (Interrupt) @ 0 (0) ---
    97        kill -SIGINT <bash_PID> is ignored, back to waiting:
    98    23:48:50.619705 waitpid(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGINT}], 0) = 13555
    99        sleep was killed by "killall -SIGINT sleep".
    100        This is the second one in a row. Kill ourself:
    101    23:48:51.504604 kill(13515, SIGINT)     = 0
    102    23:48:51.504689 --- SIGINT (Interrupt) @ 0 (0) ---
    103    23:48:51.504915 +++ killed by SIGINT +++
    104    
    105    As long as there is at least one "sleep 5" which exited successfully
    106    (not killed by SIGINT), bash continues. This is not documented anywhere
    107    AFAIKS.
    108    
    109    Why keyboard ^C acts differently?
    110    
    111    00:08:07.655985 clone(...) = 14270
    112    00:08:07.669707 waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 14270
    113    00:08:12.656872 --- SIGCHLD (Child exited) @ 0 (0) ---
    114    00:08:12.657743 clone(...) = 14273
    115    00:08:12.671708 waitpid(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGINT}], 0) = 14273
    116    00:08:13.810778 --- SIGINT (Interrupt) @ 0 (0) ---
    117    00:08:13.818705 kill(14269, SIGINT)     = 0
    118    00:08:13.820103 --- SIGINT (Interrupt) @ 0 (0) ---
    119    00:08:13.820925 +++ killed by SIGINT +++
    120    
    121    Perhaps because at the moment bash got SIGINT it had no children?
    122    (it did not manage to spawn new sleep yet, see the trace)
    Legend:
    Removed from v.983  
    changed lines
      Added in v.984