# Quotes: Double, Single and None

Without quotes, the shell splits a variable's value at its spaces and turns a \* into file names, the number-one bash bug; "$name" in double quotes keeps the value exactly as it is, and single quotes keep everything as typed.

Journeyman · Unix · Linux · Updated November 10, 2026

## After this lesson you can

- Put double quotes around every $name, so spaces and \* in a value stay as they are
- Choose double quotes, single quotes or none for a piece of text in a command

## Key takeaways

- Without quotes, the shell cuts a $name's value into words at its spaces and swaps a * in it for file names. This is word splitting.
- Put double quotes around every $name, $1, "$@" and $( ): "$card" stays one piece, spaces and stars included.
- Single quotes keep everything exactly as typed, $ included. Use them for text that should never change.
- Leave the quotes off only when you want the shell to act, as with a wildcard in ls *.txt. A ~ inside quotes isn't your home folder.

Aunt Rosa sent a thank-you note, and it's saved as `Aunt Rosa.txt`. Your script keeps the file's name in a variable and prints it with `cat $card`. Instead of the note, out comes Rosa's shopping list, from a different file. Swap `cat` for `rm`, and the script deletes a file you never named. It's the number-one bug in bash scripts, and it catches out experienced developers and admins too. The fix is two characters, a pair of double quotes, and the habit takes a minute to learn.

The examples use the card shop from *Arguments: $1, $# and "$@"*. Add two files to it, one with a space in its name:

```bash
cd ~/terminal-practice/cards
printf 'Dear Aunt Rosa,\nThank you for the scarf!\n' > 'Aunt Rosa.txt'
printf 'eggs\nflour\nbirthday candles\n' > Rosa.txt
pwd
```

```text
/home/sam/terminal-practice/cards
```

## What the shell does to a bare $name

Keep the note's name in a variable, and print it without quotes:

```bash
card='Aunt Rosa.txt'
cat $card
```

```text
eggs
flour
birthday candles
cat: Aunt: No such file or directory
```

After the shell fills in `$card`, it cuts the value into words at every space, the same way it cuts a line into arguments. `cat` received two names, `Aunt` and `Rosa.txt`. There's no file called `Aunt`, and `Rosa.txt` is the shopping list. Cutting a value apart like this is called **word splitting**. (The order of the lines and the wording of the error differ from system to system; the two names are the same everywhere.)

![Two ways to hand the value Aunt Rosa.txt to cat. Without quotes, cat $card: the shell cuts the value at its space into two names, Aunt and Rosa.txt, so cat finds no file called Aunt and prints Rosa.txt, the wrong file. With quotes, cat "$card": the value arrives as one name, Aunt Rosa.txt, and cat prints Aunt Rosa's note](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/5932c137098b4967bde2632ed22bcba3.webp)

That's not all the shell does to a bare value. A `*` in it is a wildcard, the same as one you typed:

```bash
note='Thanks a million * from all of us'
echo $note
```

```text
Thanks a million Aunt Rosa.txt Rosa.txt args.sh ask-card.sh card-for-Maya.txt card.sh greeting.sh party.sh secret-card.sh from all of us
```

The star became every file in the folder. Your list shows whatever is in yours.

## Double quotes: "$name", always

Double quotes tell the shell: fill in the value, then leave it alone. No splitting at spaces, no wildcards:

```bash
cat "$card"
echo "$note"
```

```text
Dear Aunt Rosa,
Thank you for the scarf!
Thanks a million * from all of us
```

The rule that prevents this whole family of bugs: **put double quotes around every `$`**: `"$card"`, `"$1"`, `"$@"`, and the `"$(date +%F)"` of *Values from Commands: $( ) and $(( ))*. You'll rarely be wrong with them, and a script without them works only until the first name with a space. ShellCheck, from *Writing Scripts in VS Code*, underlines a `$name` without quotes for exactly this reason.

Double quotes still fill in every `$`. An apostrophe is fine inside them, so `echo "It's Maya's card"` prints `It's Maya's card`.

## Single quotes: exactly as typed

Sometimes a `$` is a dollar sign. In double quotes, bash reads `$5` as the fifth argument from *Arguments: $1, $# and "$@"*, which is empty at the prompt:

```bash
echo "Cards cost $5 each"
echo 'Cards cost $5 each'
echo "Cards cost \$5 each"
```

```text
Cards cost  each
Cards cost $5 each
Cards cost $5 each
```

Single quotes keep everything between them exactly as typed: no `$`, no wildcards, no splitting. Use them for text that should never change, such as `printf`'s pattern or a price. A backslash, `\` (read "backslash"), does the same for one character, so `\$5` inside double quotes is a dollar sign too. A single quote can't go inside single quotes; put that text in double quotes instead.

## No quotes: when you want the shell to act

Leave the quotes off when you want the shell to do its work: to turn a wildcard into names, or `~` into your home folder. Quotes switch both off:

```bash
ls *.txt
ls "*.txt"
cd "~/terminal-practice"
```

```text
'Aunt Rosa.txt'   Rosa.txt   card-for-Maya.txt
ls: cannot access '*.txt': No such file or directory
bash: cd: ~/terminal-practice: No such file or directory
```

In quotes, `*.txt` is a file literally called `*.txt`, and `~` is a folder literally called `~`. Keep those outside the quotes and quote the rest, as in `cd ~/"photos to print"` or `"$HOME/photos to print"`.

The choice, in three lines:

- **Double quotes** around anything with a `$`: the value is filled in and kept in one piece.
- **Single quotes** around text that must stay exactly as typed.
- **No quotes** where you want a wildcard, a `~` or `{a,b}` to be expanded.

zsh at a Mac's prompt doesn't split a bare `$name` at spaces or expand a `*` in it, which hides this bug while you test there. Your scripts run in bash, where it bites, so quote them anyway.

## Check yourself

2 questions to try on the lesson page.

## So what

Double quotes around every `$`, single quotes for exactly-as-typed and no quotes only when you want a wildcard to work: that one habit keeps a name with a space from turning into the wrong file.

## Key terms

- [Quoting](https://www.ask-codey.com/glossary/quoting)
- [Word Splitting](https://www.ask-codey.com/glossary/word-splitting)
- [Glob](https://www.ask-codey.com/glossary/glob)
- [Wildcard](https://www.ask-codey.com/glossary/wildcard)

## Cheat sheets

- [Quotes: Double, Single and None](https://www.ask-codey.com/cheat-sheets/bash-quoting-cheat-sheet)

## Related

- [Variables in the Shell](https://www.ask-codey.com/lessons/bash-shell-variables)
- [Arguments: $1, $# and "$@"](https://www.ask-codey.com/lessons/bash-script-arguments)
- [Values from Commands: $( ) and $(( ))](https://www.ask-codey.com/lessons/bash-command-substitution)

Source: https://www.ask-codey.com/lessons/bash-quoting