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32 .\" @(#)system.3 8.1 (Berkeley) 6/4/93

33 .\" $FreeBSD: src/lib/libc/stdlib/system.3,v 1.13 2008/06/26 08:24:59 danger Exp $

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35 .Dd June 4, 1993

36 .Dt SYSTEM 3

37 .Os

38 .Sh NAME

39 .Nm system

40 .Nd pass a command to the shell

41 .Sh LIBRARY

42 .Lb libc

43 .Sh SYNOPSIS

44 .In stdlib.h

45 .Ft int

46 .Fn system "const char *command"

47 .Sh DESCRIPTION

48 The

49 .Fn system

50 function

51 hands the argument

52 .Fa command

53 to the command interpreter

54 .Xr sh 1 .

55 The calling process waits for the shell

56 to finish executing the command,

57 ignoring

58 .Dv SIGINT

59 and

60 .Dv SIGQUIT ,

61 and blocking

62 .Dv SIGCHLD .

63 .Pp

64 If

65 .Fa command

66 is a

67 .Dv NULL

68 pointer,

69 .Fn system

70 will return non-zero if the command interpreter

71 .Xr sh 1

72 is available, and zero if it is not.

73 .Sh RETURN VALUES

74 The

75 .Fn system

76 function

77 returns the exit status of the shell as returned by

78 .Xr waitpid 2 ,

79 or \-1 if an error occurred when invoking

80 .Xr fork 2

81 or

82 .Xr waitpid 2 .

83 A return value of 127 means the execution of the shell

84 failed.

85 .Sh SEE ALSO

86 .Xr sh 1 ,

87 .Xr execve 2 ,

88 .Xr fork 2 ,

89 .Xr waitpid 2 ,

90 .Xr popen 3

91 .Sh STANDARDS

92 The

93 .Fn system

94 function

95 conforms to

96 .St -isoC

97 and is expected to be

98 .St -p1003.2

99 compatible.