Linux env command
env is a shell command for Linux, Unix, and Unix-like operating systems. It can print a list of the current environment variables, or to run another program in a custom environment without modifying the current one.
Description
If env is run without any options, it prints the variables of the current environment. Otherwise, env sets each NAME to VALUE and executes COMMAND.
Syntax
env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]
Options
| -i, --ignore-environment |
Start with an empty environment. |
| -0, --null | End each output line with a 0 (null) byte rather than a newline. |
| -u, --unset=NAME | Remove variable NAME from the environment. |
| --help | Display a help message and exit. |
| --version | Display version information and exit. |
| - | Same as -i. |
Examples
env
Executing env with no options displays the current environment variables and their values. Output looks similar to the following:
HOME=/computerhope/public_html PATH=/usr/local/bin: LOGNAME=admin HZ=100 TERM=vt100 TZ=MST7MDT SHELL=/bin/csh MAIL=/var/mail/computerhope _INIT_UTS_PLATFORM=SUNW,SPARCstation-10 _INIT_UTS_RELEASE=5.7 _INIT_UTS_SYSNAME=SunOS _INIT_UTS_VERSION=Generic_106541-08 EDITOR=pico -t OPENWINHOME=/usr/openwin MANPATH=/usr/man:/usr/local/man:/usr/openwin/man LD_LIBRARY_PATH=/usr/local/lib:/usr/openwin/lib PAGER=more
Below is brief description of some commonly-used environment variables:
| EDITOR | The default file editor to be used. |
| HOME | The current user's home directory. |
| SHELL | The location of the current user's shell program. |
| TERM | The current terminal emulation. |
| PATH | Pathnames to be searched when executing commands. |
| Location of where mail is to be stored. | |
| MANPATH | Location of your manuals. See man command. |
| LOGNAME | The name of the current user. |
| TZ | The time zone used by the system clock. |
Related commands
csh — The C shell command interpreter.
ksh — The Korn shell command interpreter.
logname — Return a user's login name.
printenv — Print all or part of the environment.
sh — The Bourne shell command interpreter.