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man pages section 1: User Commands

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Updated: Thursday, June 13, 2019
 
 

env(1)

Name

env - set environment for command invocation

Synopsis

/usr/bin/env [-]  [-i | --ignore-environment] [name=value]... 
     [-0 | --null] [-u name | --unset=name]... [--help]
     [utility [arg... ]]
/usr/xpg4/bin/env [-]  [-i | --ignore-environment] [name=value]... 
     [-0 | --null] [-u name | --unset=name]... [--help]
     [utility [arg... ]]

Description

The env utility obtains the current environment, modifies it according to its arguments, then invokes the utility named by the utility operand with the modified environment.

Optional arguments are passed to utility. If no utility operand is specified, the resulting environment is written to the standard output, with one name=value pair per line.

/usr/bin

If env executes commands with arguments, it uses the default shell /usr/bin/sh (see sh(1)).

/usr/xpg4/bin

If env executes commands with arguments, it uses /usr/xpg4/bin/sh (see ksh88(1)).

Options

The following options are supported:

–-help

Display usage message and exit.

–i | | –-ignore-environment

Ignores the environment that would otherwise be inherited from the current shell. Restricts the environment for utility to that specified by the arguments.

–0, –-null

End each output line with a zero byte rather than with a newline.

–u name, –-unset=name

Remove variable name from the environment.

Operands

The following operands are supported:

name=value

Arguments of the form name=value modify the execution environment, and are placed into the inherited environment before utility is invoked.

utility

The name of the utility to be invoked. If utility names any of the special shell built-in utilities, the results are undefined.

arg

A string to pass as an argument for the invoked utility.

Examples

Example 1 Invoking utilities with new PATH values

The following utility:

example% env -i PATH=/mybin mygrep xyz myfile

invokes the utility mygrep with a new PATH value as the only entry in its environment. In this case, PATH is used to locate mygrep, which then must reside in /mybin.

Environment Variables

See environ(7) for descriptions of the following environment variables that affect the execution of env: LANG, LC_ALL , LC_CTYPE, LC_MESSAGES, and NLSPATH.

PATH

Determine the location of the utility. If PATH is specified as a name=value operand to env, the value given shall be used in the search for utility.

Exit Status

If utility is invoked, the exit status of env is the exit status of utility. Otherwise, the env utility returns one of the following exit values:

0

Successful completion.

1-125

An error occurred.

126

utility was found but could not be invoked.

127

utility could not be found.

Attributes

See attributes(7) for descriptions of the following attributes:

/usr/bin

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
system/core-os
CSI
enabled

/usr/xpg4/bin

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
system/xopen/xcu4
CSI
enabled
Interface Stability
Committed
Standard

See Also

ksh88(1), sh(1), exec(2), getopt_long(3C), profile(5), attributes(7), environ(7), standards(7)