The env File Format

The .env File Format

A .env file is a list of KEY=VALUE lines. This page documents exactly how each line is parsed, with the edge cases spelled out.

# Application settings
APP_NAME = InitPHP
APP_ENV  = production

DB_HOST = 127.0.0.1
DB_PORT = 5432

Reading happens lazily: the file is parsed once at create() time, but type coercion and ${VAR} interpolation happen when you call get(). This page is about the line grammar; for what the value turns into, see Value Types & Coercion and Variable Interpolation.

Keys

The line is split on the first =. Everything before it is the key, everything after is the value.

DSN = mysql:host=localhost;dbname=app
#     └── value keeps every '=' after the first one

• Whitespace around the key is trimmed: FOO = bar and FOO=bar are the same.

• An optional leading export is stripped, so a file that is also source-able by a shell works:

  export TOKEN = abc123      # key is TOKEN

  The prefix must be the literal word export followed by a single space. export\tFOO (a tab) is not treated as the prefix.

Comments

A line is a comment when its first character (after trimming) is anything other than a letter, a digit, _, or -. So every one of these is ignored:

# hash comment
; semicolon comment
// double-slash comment
* star comment

Blank lines are ignored too.

Inline comments

An inline comment begins at the first # that is preceded by whitespace. The # and everything after it are dropped:

URL = https://example.test   # everything here is a comment
#                            └── value becomes "https://example.test"

A # that is not preceded by whitespace is part of the value. This keeps hex colours, URL fragments and the like intact:

COLOR    = #ffffff       # value: "#ffffff"
FRAGMENT = page#section  # value: "page#section"

Why the whitespace rule? Without it, COLOR=#ffffff would be read as an empty value followed by a comment. Requiring a space before # lets a value legitimately start with #.

Quoting

Wrap a value in matching single (') or double (") quotes to take it verbatim. The surrounding quotes are removed; everything between them — including a #, spaces, or the other quote character — is preserved.

GREETING = "hello world"       # value: hello world
PADDED   = "  keep my spaces " # value: "  keep my spaces " (inner spaces kept)
HASH     = "#ffffff"           # value: #ffffff
APOS     = "it's fine"         # value: it's fine

Quoting works even when there is whitespace around the =:

SITE = "https://example.test"  # value: https://example.test

An inline comment is still recognised after the closing quote:

TOKEN = "abc" # secret         # value: abc

Escape sequences are not processed inside quotes — \n, \t and \" are kept literally. If you need real newlines or tabs in a value, set them another way (for example through a .env.php file).

Whitespace

Leading and trailing whitespace is trimmed from both the key and the value:

   SPACED   =    value with trailing spaces
#  └ key: "SPACED", value: "value with trailing spaces"

To preserve leading/trailing spaces in a value, quote it (see above).

Malformed lines

A non-comment line with no = is ignored rather than producing a junk entry. It does not raise a warning:

THIS_LINE_IS_IGNORED
VALID = 1                 # only VALID is defined

Parsing cheat-sheet

Line	Parsed key	Parsed value
FOO=bar	FOO	bar
FOO = bar	FOO	bar
export FOO=bar	FOO	bar
FOO="a b"	FOO	a b
FOO='a b'	FOO	a b
FOO=a # c	FOO	a
FOO=#abc	FOO	#abc
FOO=a#b	FOO	a#b
FOO=mysql:a=b	FOO	mysql:a=b
# comment	—	(ignored)
; comment	—	(ignored)
NO_EQUALS_HERE	—	(ignored)
(blank)	—	(ignored)

Next steps

• Value Types & Coercion — what the parsed string becomes when you read it
• Variable Interpolation — ${VAR} references
• Using a PHP .env File — native types via a PHP array