.Dd January 24, 2015
.Dt ENV 1
.Os
.Sh NAME
.Nm env
.Nd modify the environment, then print it or run a command
.Sh SYNOPSIS
.Nm
.Op Fl i
.Oo Fl u Ar variable Oc ...
.Oo Ar variable Ns = Ns Ar value Oc ...
.Oo Ar cmd Oo arg ... Oc Oc
.Sh DESCRIPTION
.Nm
unsets each
.Ar variable ,
then adds or sets each
.Ar ( variable , value )
tuple in the environment.
.Pp
If
.Ar cmd
is given, it is executed in this new environment;
otherwise, the modified environment is printed to stdout.
.Sh OPTIONS
.Bl -tag -width Ds
.It Fl i
Completely ignore the existing environment and execute
.Ar cmd
only with each
.Ar ( variable , value )
tuple specified.
.It Fl u Ar variable
Unset
.Ar variable
in the environment.
.El
.Sh SEE ALSO
.Xr printenv 1 ,
.Xr putenv 3 ,
.Xr environ 7
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.
.Pp
The
.Op Fl u
flag is an extension to that specification.