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.\" Copyright 2020 Scott Long
.\" Copyright 2020 Stefan Eßer
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.Dd November 25, 2020
.Dt GETLOCALBASE 3
.Os
.Sh NAME
.Nm getlocalbase
.Nd "return the path to the local software directory"
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.In libutil.h
.Ft const char*
.Fn getlocalbase "void"
.Sh DESCRIPTION
The
.Fn getlocalbase
function returns the path to the local software base directory.
Normally this is the
.Pa /usr/local
directory.
First the
.Ev LOCALBASE
environment variable is checked.
If that does not exist then the
.Va user.localbase
sysctl is checked.
If that also does not exist then the value of the
.Dv _PATH_LOCALBASE
compile-time variable is used.
If that is undefined then the default of
.Pa /usr/local
is used.
.Pp
The contents of the string returned by the
.Fn getlocalbase
function shall not be modified.
.Sh IMPLEMENTATION NOTES
Calls to
.Fn getlocalbase
will perform a setugid check on the running binary before checking the
environment.
.Pp
The address returned by
.Fn getlocalbase
will point into the executing processes environment if it is the result of
.Fn getenv "LOCALBASE" ,
to a static buffer if it is the result of
.Fn sysctl "user.localbase" ,
and to a constant string if the compiled in default value is returned.
.Pp
The same value will be returned on successive calls during the run-time
of the program, ignoring any changes to the environment variable or the
sysctl value that might have been made.
.Pp
The
.Fn getlocalbase
function can be compiled with a non-default value of LOCALBASE_CTL_LEN.
A value of 0 will disable fetching of the sysctl value, a value less than
MAXPATHLEN will put a limit on the maximum string length supported for
this sysctl value.
If built with a non-default value of LOCALBASE_CTL_LEN, a value of the
user.localbase sysctl variable longer than this value will make
.Fn getlocalbase
return a valid string that is not a valid path prefix in any filesystem.
.Sh RETURN VALUES
The
.Fn getlocalbase
function returns a pointer to a string, whose length may exceed MAXPATHLEN,
if it has been obtained from the environment.
.Sh ENVIRONMENT
The
.Fn getlocalbase
library function retrieves the
.Ev LOCALBASE
environment variable.
.Sh ERRORS
The
.Fn getlocalbase
function always succeeds and returns a valid pointer to a string.
.Sh SEE ALSO
.Xr env 1 ,
.Xr src.conf 5 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
library function first appeared in
.Fx 13.0 .
.Sh AUTHORS
This
manual page was written by
.An Scott Long Aq Mt scottl@FreeBSD.org and Stefan Eßer Aq Mt se@FreeBSD.org .