xref: /freebsd/usr.bin/printenv/printenv.1 (revision c17d43407fe04133a94055b0dbc7ea8965654a9f)
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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
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 Ns = Ns Ar 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.
55If
56.Ar name
57is specified, only
58its value is printed.
59.Pp
60Some shells may provide a builtin
61.Nm
62command which is similar or identical to this utility.
63Consult the
64.Xr builtin 1
65manual page.
66.Pp
67.Nm Env
68executes
69.Ar command
70after modifying the environment as
71specified on the command line.
72The option
73.Ar name Ns = Ns Ar value
74specifies
75an environment variable,
76.Ar name  ,
77with a value of
78.Ar value  .
79.Pp
80The options are as follows:
81.Bl -tag -width indent
82.It Fl i
83Execute the
84.Ar command
85with only those environment values specified.
86The environment inherited
87by
88.Nm env
89is ignored completely.
90.It Fl
91Identical to the
92.Fl i
93option, available for backward compatibility.
94.El
95.Pp
96If no command is specified,
97.Nm env
98prints out the names and values
99of the variables in the environment, with one name/value pair per line.
100.Pp
101.Nm env
102is sometimes useful with the
103.Dq Li #!
104construct (see
105.Xr execve 2 ) .
106The only difference between
107.Dq Li #!/usr/local/bin/foo
108and
109.Dq Li "#!/usr/bin/env\ /usr/local/bin/foo"
110is that the latter works even if
111.Pa /usr/local/bin/foo
112is itself interpreted.
113Using
114.Nm env
115this way also allows one to reference
116.Pa foo
117without the path,
118as well as set up the environment as desired.
119.Sh DIAGNOSTICS
120.Ex -std printenv
121.Pp
122.Ex -std env
123An exit status of 126 indicates
124.Ar command
125was found, but could not be executed.
126An exit status of 127 indicates
127.Ar command
128could not be found.
129.Sh SEE ALSO
130.Xr csh 1 ,
131.Xr sh 1 ,
132.Xr execvp 3 ,
133.Xr environ 7
134.Sh STANDARDS
135The
136.Nm env
137utility conforms to
138.St -p1003.1-2001 .
139.Sh HISTORY
140The
141.Nm
142command appeared in
143.Bx 3.0 .
144.Sh BUGS
145.Nm Env
146doesn't handle commands with equal (``='') signs in their
147names, for obvious reasons.
148