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author | yar <yar@FreeBSD.org> | 2004-06-07 11:01:39 +0000 |
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committer | yar <yar@FreeBSD.org> | 2004-06-07 11:01:39 +0000 |
commit | 68060b2236dc8453f4a0471f0b41e12e21711d18 (patch) | |
tree | 13efc13191bd58a4e268f252e63b25106b748ed5 /lib/libc/gen/signal.3 | |
parent | 76e830207900fd1ac155c5d6702335b25fff43de (diff) | |
download | FreeBSD-src-68060b2236dc8453f4a0471f0b41e12e21711d18.zip FreeBSD-src-68060b2236dc8453f4a0471f0b41e12e21711d18.tar.gz |
Finally document the option to avoid zombie creation
through ignoring SIGCHLD.
Diffstat (limited to 'lib/libc/gen/signal.3')
-rw-r--r-- | lib/libc/gen/signal.3 | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/lib/libc/gen/signal.3 b/lib/libc/gen/signal.3 index 74c6531..b329691 100644 --- a/lib/libc/gen/signal.3 +++ b/lib/libc/gen/signal.3 @@ -32,7 +32,7 @@ .\" @(#)signal.3 8.3 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd April 19, 1994 +.Dd June 7, 2004 .Dt SIGNAL 3 .Os .Sh NAME @@ -204,6 +204,22 @@ to the function; ignored signals remain ignored. .Pp +If a process explicitly specifies +.Dv SIG_IGN +as the action for the signal +.Dv SIGCHLD , +the system will not create zombie processes when children +of the calling process exit. +As a consequence, the system will discard the exit status +from the child processes. +If the calling process subsequently issues a call to +.Xr wait 2 +or equivalent, it will block until all of the calling process's +children terminate, and then return a value of \-1 with +.Va errno +set to +.Er ECHILD . +.Pp See .Xr sigaction 2 for a list of functions @@ -239,6 +255,7 @@ or .Xr sigaltstack 2 , .Xr sigprocmask 2 , .Xr sigsuspend 2 , +.Xr wait 2 , .Xr fpsetmask 3 , .Xr setjmp 3 , .Xr siginterrupt 3 , @@ -248,3 +265,7 @@ This .Fn signal facility appeared in .Bx 4.0 . +The option to avoid the creation of child zombies through ignoring +.Dv SIGCHLD +appeared in +.Fx 5.0 . |