$ Linux Command

Shell

env

Show or run commands with environment variables.

environmentvariableshellcommandscript

Additional Notes

env prints the current environment or runs a command with modified environment variables.

Environment variables are inherited by child processes and are often used for paths, credentials, editor choices, locale, and application configuration.

Syntax

env [options] [NAME=VALUE...] [command [args...]]

Parameters

  • options: Flags that change how env behaves.
  • arguments: Values consumed by the shell builtin or script command.
  • command: Command line to run, test, wrap, or control.

Common Options

  • -i, --ignore-environment: Start with an empty environment.
  • -u NAME, --unset=NAME: Remove a variable before running the command.
  • -0, --null: End output entries with null characters.

Examples

env

Print environment variables.

env | sort

Print variables in sorted order.

env DEBUG=1 ./app

Run a command with one extra variable.

env -u HTTP_PROXY curl https://example.com

Run a command with one variable removed.

env -i PATH=/usr/bin:/bin bash --noprofile --norc

Start a shell with a minimal environment.

Practical Notes

  • env NAME=value command affects only that command and its children.
  • Use export NAME=value to make a shell variable part of the environment.
  • Be careful printing environments because they may contain secrets.
  • Many scripts use /usr/bin/env python3 to find an interpreter from PATH.