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34 .\" @(#)_exit.2 8.1 (Berkeley) 6/4/93

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36 .Dd June 4, 1993

37 .Dt EXIT 2

38 .Os BSD 4

39 .Sh NAME

40 .Nm _exit

41 .Nd terminate the calling process

42 .Sh SYNOPSIS

43 .Fd #include <unistd.h>

44 .Ft void

45 .Fo _exit

46 .Fa "int status"

47 .Fc

48 .Sh DESCRIPTION

49 The

50 .Fn _exit

51 function

52 terminates a process, with the following consequences:

53 .Bl -bullet

54 .It

55 All of the descriptors that were open in the calling process are closed.

56 This may entail delays; for example, waiting for output to drain.

57 A process in this state may not be killed, as it is already dying.

58 .It

59 If the parent process of the calling process has an outstanding

60 .Xr wait

61 call

62 or catches the

63 .Dv SIGCHLD

64 signal,

65 it is notified of the calling process's termination;

66 the

67 .Em status

68 is set as defined by

69 .Xr wait 2 .

70 .It

71 The parent process-ID of all of the calling process's existing child

72 processes are set to 1; the initialization process

73 (see the DEFINITIONS section of

74 .Xr intro 2 )

75 inherits each of these processes.

76 .It

77 If the termination of the process causes any process group

78 to become orphaned (usually because the parents of all members

79 of the group have now exited; see

80 .Dq orphaned process group

81 in

82 .Xr intro 2 ) ,

83 and if any member of the orphaned group is stopped,

84 the

85 .Dv SIGHUP

86 signal and the

87 .Dv SIGCONT

88 signal are sent to all members of the newly-orphaned process group.

89 .It

90 If the process is a controlling process (see

91 .Xr intro 2 ) ,

92 the

93 .Dv SIGHUP

94 signal is sent to the foreground process group of the controlling terminal.

95 All current access to the controlling terminal is revoked.

96 .El

97 .Pp

98 Most C programs call the library routine

99 .Xr exit 3 ,

100 which flushes buffers, closes streams, unlinks temporary files, etc.,

101 before

102 calling

103 .Fn _exit .

104 .Sh RETURN VALUE

105 .Fn _exit

106 can never return.

107 .Sh SEE ALSO

108 .Xr fork 2 ,

109 .Xr sigaction 2 ,

110 .Xr wait 2 ,

111 .Xr exit 3

112 .Sh STANDARDS

113 The

114 .Nm _exit

115 function is defined by

116 .St -p1003.1-88 .