Skip to main content

​
Overview

The env command displays all environment variables currently set in the Nash shell session. Each variable is printed in KEY=VALUE format, one per line.

​
Syntax

env

​
Description

The env command takes no arguments and lists all environment variables in the current shell context. This includes:
  • Default Nash environment variables (USER, HOME, PATH, etc.)
  • Variables set with export
  • Variables passed via -E flag at Nash startup
  • Variables inherited from parent environment

​
Options

The Nash env command does not accept any options or arguments. It always displays all environment variables.

​
Examples

​
Display All Variables

env
# Output:
# USER=user
# LOGNAME=user
# HOME=/home/user
# SHELL=nash
# TERM=xterm-256color
# LANG=en_US.UTF-8
# LC_ALL=en_US.UTF-8
# PATH=/usr/local/bin:/usr/bin:/bin
# PWD=/home/user
# HOSTNAME=nash
# SHLVL=1

​
Filter Specific Variables

env | grep PATH
# Output: PATH=/usr/local/bin:/usr/bin:/bin

​
Count Variables

env | wc -l
# Output: 11

​
Search for Variable Pattern

env | grep -i lang
# Output:
# LANG=en_US.UTF-8
# LC_ALL=en_US.UTF-8

​
Sort Variables Alphabetically

env | sort

​
Practical Use Cases

​
Debug Environment Issues

# Check if required variable is set
env | grep API_KEY

​
Export Environment Snapshot

# Save current environment to file
env > environment-backup.txt

​
Compare Environments

# Before making changes
env | sort > env-before.txt

# After making changes
env | sort > env-after.txt

# View differences
grep -v -f env-before.txt env-after.txt

​
Verify Path Configuration

# Extract and display PATH
env | grep PATH | cut -d= -f2
# Output: /usr/local/bin:/usr/bin:/bin

​
Check User Context

# View user-related variables
env | grep -E "USER|HOME|SHELL"
# Output:
# USER=user
# HOME=/home/user
# SHELL=nash

​
Default Environment Variables

Nash sets these standard Unix environment variables by default:
​
USER
string
Current username (set via -U flag or defaults to user)
​
LOGNAME
string
Same as USER - login name
​
HOME
string
User’s home directory (/home/<username>)
​
SHELL
string
Current shell (nash)
​
TERM
string
Terminal type (xterm-256color)
​
LANG
string
System language (en_US.UTF-8)
​
LC_ALL
string
Locale setting (en_US.UTF-8)
​
PATH
string
Executable search path (/usr/local/bin:/usr/bin:/bin)
​
PWD
string
Current working directory (updated by cd)
​
OLDPWD
string
Previous working directory (used by cd -)
​
HOSTNAME
string
System hostname (nash)
​
SHLVL
string
Shell nesting level (starts at 1)

​
Output Format

Each environment variable is printed as: 
KEY=VALUE
  • No spaces around the = sign
  • One variable per line
  • No special formatting or quoting
  • Order is not guaranteed

​
Notes

  • Variables with empty values are shown as KEY=
  • The output includes all variables, not just exported ones
  • Variable values may contain special characters or spaces
  • Use export to modify variables and unset to remove them

​
Exit Status

The env command always returns exit code 0 (success).
  • export - Set or modify environment variables
  • unset - Remove environment variables
  • echo - Display variable values with echo $VAR
  • grep - Filter environment variable output

Build docs developers (and LLMs) love

Get started for freeTalk to us