xref: /freebsd/usr.bin/printenv/printenv.1 (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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34.\"	@(#)printenv.1	8.1 (Berkeley) 6/6/93
35.\" $FreeBSD$
36.\"
37.Dd June 6, 1993
38.Dt PRINTENV 1
39.Os BSD 3
40.Sh NAME
41.Nm printenv , env
42.Nd print out the environment, set and print environment
43.Sh SYNOPSIS
44.Nm
45.Op Ar name
46.Nm env
47.Op Fl
48.Op Fl i
49.Op Ar name=value ...\&
50.Op Ar command
51.Sh DESCRIPTION
52.Nm Printenv
53prints out the names and values of the variables in the environment,
54with one name/value pair per line.  If
55.Ar name
56is specified, only
57its value is printed.
58.Pp
59If a
60.Ar name
61is specified and it is not defined in the environment,
62.Nm
63returns exit status 1, else it returns status 0.
64.Pp
65Some shells may provide a builtin
66.Nm
67command which is similar or identical to this utility.
68Consult the
69.Xr builtin 1
70manual page.
71.Pp
72.Nm Env
73executes
74.Ar command
75after modifying the environment as
76specified on the command line.  The option
77.Ar name=value
78specifies
79an environment variable,
80.Ar name  ,
81with a value of
82.Ar value  .
83.Pp
84The options are as follows:
85.Bl -tag -width indent
86.It Fl i
87Execute the
88.Ar command
89with only those environment values specified.
90The environment inherited
91by
92.Nm env
93is ignored completely.
94.It Fl
95Identical to the
96.Fl i
97option, available for backward compatibility.
98.El
99.Pp
100If no command is specified,
101.Nm env
102prints out the names and values
103of the variables in the environment, with one name/value pair per line.
104.Pp
105.Nm env
106is sometimes useful with the
107.Qq #!
108construct (see
109.Xr execve 2 ) .
110The only difference between
111.Qq #!/usr/local/bin/foo
112and
113.Qq #!/usr/bin/env /usr/local/bin/foo
114is that the latter works even if
115.Pa /usr/local/bin/foo
116is itself interpreted.
117Using
118.Nm env
119this way also allows one to reference
120.Pa foo
121without the path,
122as well as set up the environment as desired.
123.Sh SEE ALSO
124.Xr csh 1 ,
125.Xr sh 1 ,
126.Xr execvp 3 ,
127.Xr environ 7
128.Sh HISTORY
129The
130.Nm
131command appeared in
132.Bx 3.0 .
133.Sh BUGS
134.Nm Env
135doesn't handle commands with equal (``='') signs in their
136names, for obvious reasons.
137