xref: /freebsd/lib/libc/gen/getosreldate.3 (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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25.\" $FreeBSD$
26.\"
27.Dd June 13, 2018
28.Dt GETOSRELDATE 3
29.Os
30.Sh NAME
31.Nm getosreldate
32.Nd get the value of
33.Dv __FreeBSD_version
34.Sh LIBRARY
35.Lb libc
36.Sh SYNOPSIS
37.In unistd.h
38.Ft int
39.Fn getosreldate void
40.Sh DESCRIPTION
41The
42.Fn getosreldate
43function returns an integer showing the version of the
44currently running
45.Fx
46kernel.
47Definitions of the values can be found in
48.%B "The Porter's Handbook":
49.Pp
50.Lk https://www.FreeBSD.org/doc/en/books/porters-handbook/
51.Sh RETURN VALUES
52Upon successful completion,
53.Fn getosreldate
54returns the value requested;
55otherwise the value \-1 is returned and the global variable
56.Va errno
57is set to indicate the error.
58.Sh ENVIRONMENT
59.Bl -tag -width ".Ev OSVERSION"
60.It Ev OSVERSION
61If the environment variable
62.Ev OSVERSION
63is set, it will override the
64.Fn getosreldate
65return value.
66.El
67.Sh EXAMPLES
68An example can be found in
69.Pa /usr/share/examples/FreeBSD_version .
70.Sh ERRORS
71The
72.Fn getosreldate
73function may fail and set
74.Va errno
75for any of the errors specified for the library function
76.Xr sysctl 3 .
77.Sh SEE ALSO
78.Rs
79.%B "The Porter's Handbook"
80.Re
81.Sh HISTORY
82The
83.Fn getosreldate
84function appeared in
85.Fx 2.0 .
86