xref: /freebsd/usr.bin/printenv/printenv.1 (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
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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
52The
53.Nm
54utility prints out the names and values of the variables in the environment,
55with one name/value pair per line.
56If
57.Ar name
58is specified, only
59its value is printed.
60.Pp
61Some shells may provide a builtin
62.Nm
63command which is similar or identical to this utility.
64Consult the
65.Xr builtin 1
66manual page.
67.Pp
68The
69.Nm env
70utility executes
71.Ar command
72after modifying the environment as
73specified on the command line.
74The option
75.Ar name Ns = Ns Ar value
76specifies
77an environment variable,
78.Ar name  ,
79with a value of
80.Ar value  .
81.Pp
82The options are as follows:
83.Bl -tag -width indent
84.It Fl i
85Execute the
86.Ar command
87with only those environment values specified.
88The environment inherited
89by
90.Nm env
91is ignored completely.
92.It Fl
93Identical to the
94.Fl i
95option, available for backward compatibility.
96.El
97.Pp
98If no command is specified,
99.Nm env
100prints out the names and values
101of the variables in the environment, with one name/value pair per line.
102.Pp
103The
104.Nm env
105utility is sometimes useful with the
106.Dq Li #!
107construct (see
108.Xr execve 2 ) .
109The only difference between
110.Dq Li #!/usr/local/bin/foo
111and
112.Dq Li "#!/usr/bin/env\ /usr/local/bin/foo"
113is that the latter works even if
114.Pa /usr/local/bin/foo
115is itself interpreted.
116Using
117.Nm env
118this way also allows one to reference
119.Pa foo
120without the path,
121as well as set up the environment as desired.
122.Sh DIAGNOSTICS
123.Ex -std printenv
124.Pp
125.Ex -std env
126An exit status of 126 indicates
127.Ar command
128was found, but could not be executed.
129An exit status of 127 indicates
130.Ar command
131could not be found.
132.Sh SEE ALSO
133.Xr csh 1 ,
134.Xr sh 1 ,
135.Xr execvp 3 ,
136.Xr environ 7
137.Sh STANDARDS
138The
139.Nm env
140utility conforms to
141.St -p1003.1-2001 .
142.Sh HISTORY
143The
144.Nm
145command appeared in
146.Bx 3.0 .
147.Sh BUGS
148The
149.Nm env
150utility doesn't handle commands with equal (``='') signs in their
151names, for obvious reasons.
152