xref: /freebsd/lib/libsys/closefrom.2 (revision 1edb7116)
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26.Dd March 3, 2022
27.Dt CLOSEFROM 2
28.Os
29.Sh NAME
30.Nm closefrom ,
31.Nm close_range
32.Nd delete open file descriptors
33.Sh LIBRARY
34.Lb libc
35.Sh SYNOPSIS
36.In unistd.h
37.Ft void
38.Fn closefrom "int lowfd"
39.Ft int
40.Fn close_range "u_int lowfd" "u_int highfd" "int flags"
41.Sh DESCRIPTION
42The
43.Fn closefrom
44system call deletes all open file descriptors greater than or equal to
45.Fa lowfd
46from the per-process object reference table.
47Any errors encountered while closing file descriptors are ignored.
48.Pp
49The
50.Fn close_range
51system call deletes all open file descriptors between
52.Fa lowfd
53and
54.Fa highfd
55inclusive, clamped to the range of open file descriptors.
56Any errors encountered while closing file descriptors are ignored.
57Supported
58.Fa flags :
59.Bl -tag -width ".Dv CLOSE_RANGE_CLOEXEC"
60.It Dv CLOSE_RANGE_CLOEXEC
61Set the close-on-exec flag on descriptors in the range instead of closing them.
62.El
63.Sh RETURN VALUES
64Upon successful completion,
65.Fn close_range
66returns a value
67of 0.
68Otherwise, a value of -1 is returned and the global variable
69.Va errno
70is set to indicate the error.
71.Sh ERRORS
72The
73.Fn close_range
74system call
75will fail if:
76.Bl -tag -width Er
77.It Bq Er EINVAL
78The
79.Fa highfd
80argument is lower than the
81.Fa lowfd
82argument.
83.It Bq Er EINVAL
84An invalid flag was set.
85.El
86.Sh SEE ALSO
87.Xr close 2
88.Sh HISTORY
89The
90.Fn closefrom
91function first appeared in
92.Fx 8.0 .
93