bash-hackers-wiki/docs/syntax/expansion/wordsplit.md

# Word splitting

!!! warning "FIXME"
    to be continued!

Word splitting occurs once any of the following expansions are done (and
only then!)

-   [Parameter expansion](../../syntax/pe.md)
-   [Command substitution](../../syntax/expansion/cmdsubst.md)
-   [Arithmetic expansion](../../syntax/expansion/arith.md)

Bash will scan the results of these expansions for special `IFS`
characters that mark word boundaries. This is only done on results that
are **not double-quoted**!

## Internal Field Separator IFS

The `IFS` variable holds the characters that Bash sees as word
boundaries in this step. The default contains the characters

-   &lt;space&gt;
-   &lt;tab&gt;
-   &lt;newline&gt;

These characters are also assumed when IFS is **unset**. When `IFS` is
**empty** (nullstring), no word splitting is performed at all.

## Behaviour

The results of the expansions mentioned above are scanned for
`IFS`-characters. If **one or more** (in a sequence) of them is found,
the expansion result is split at these positions into multiple words.

This doesn't happen when the expansion results were **double-quoted**.

When a null-string (e.g., something that before expanded to
&gt;&gt;nothing&lt;&lt;) is found, it is removed, unless it is quoted (`''` or
`""`).

<u>**Again note:**</u> Without any expansion beforehand, Bash
won't perform word splitting! In this case, the initial token parsing
is solely responsible.

## See also

-   [Introduction to expansion and
    substitution](../../syntax/expansion/intro.md)
-   [Quoting and escaping](../../syntax/quoting.md)
-   [WordSplitting](http://mywiki.wooledge.org/WordSplitting),
    [IFS](http://mywiki.wooledge.org/IFS), and
    [DontReadLinesWithFor](http://mywiki.wooledge.org/DontReadLinesWithFor) -
    Greg's wiki
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00			`# Word splitting`

Updated table formatting, call-outs, html comments, improper escapes. 2024-10-08 06:00:17 +02:00			`!!! warning "FIXME"`
			`to be continued!`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00
			`Word splitting occurs once any of the following expansions are done (and`
			`only then!)`

Fix hyperlinks of markdown pages at depth 3 find docs/ -depth 3 -name '.md' \| xargs grep '(./' -l \| \ xargs -I{} \ sed -i '' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)\(.md\)\{0\})%(../../\1/\2.md)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)#\([a-zA-Z_-][0-9a-zA-Z_-]\))%(../../\1/\2.md#\3)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)\(.md\)\{0\})%(../../\1/\2/\3.md)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)#\([a-zA-Z_-][0-9a-zA-Z_-]\))%(../../\1/\2/\3.md#\4)%g' \ -e 's%](\([^:.>)#][^:.>)#]\))%](../../\1.md)%g' \ -e 's%](\([^:.>)#][^:.>)#]\)#\([^:.>)#][^:.>)#]*\))%](../../\1.md#\2)%g' \ {} Related to https://github.com/flokoe/bash-hackers-wiki/issues/10 2024-01-29 02:07:56 +01:00			`- [Parameter expansion](../../syntax/pe.md)`
			`- [Command substitution](../../syntax/expansion/cmdsubst.md)`
			`- [Arithmetic expansion](../../syntax/expansion/arith.md)`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00
			Bash will scan the results of these expansions for special `IFS`
			`characters that mark word boundaries. This is only done on results that`
			`are not double-quoted!`

			`## Internal Field Separator IFS`

			The `IFS` variable holds the characters that Bash sees as word
			`boundaries in this step. The default contains the characters`

Updated table formatting, call-outs, html comments, improper escapes. 2024-10-08 06:00:17 +02:00			`- <space>`
			`- <tab>`
			`- <newline>`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00
			These characters are also assumed when IFS is unset. When `IFS` is
			`empty (nullstring), no word splitting is performed at all.`

			`## Behaviour`

			`The results of the expansions mentioned above are scanned for`
			`IFS`-characters. If one or more (in a sequence) of them is found,
			`the expansion result is split at these positions into multiple words.`

format(docs): remove escaped t's 2024-03-30 20:09:26 +01:00			`This doesn't happen when the expansion results were double-quoted.`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00
			`When a null-string (e.g., something that before expanded to`
Updated table formatting, call-outs, html comments, improper escapes. 2024-10-08 06:00:17 +02:00			>>nothing<<) is found, it is removed, unless it is quoted (`''` or
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00			`""`).

Updated table formatting, call-outs, html comments, improper escapes. 2024-10-08 06:00:17 +02:00			`<u>Again note:</u> Without any expansion beforehand, Bash`
format(docs): remove escaped t's 2024-03-30 20:09:26 +01:00			`won't perform word splitting! In this case, the initial token parsing`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00			`is solely responsible.`

			`## See also`

			`- [Introduction to expansion and`
Fix hyperlinks of markdown pages at depth 3 find docs/ -depth 3 -name '.md' \| xargs grep '(./' -l \| \ xargs -I{} \ sed -i '' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)\(.md\)\{0\})%(../../\1/\2.md)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)#\([a-zA-Z_-][0-9a-zA-Z_-]\))%(../../\1/\2.md#\3)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)\(.md\)\{0\})%(../../\1/\2/\3.md)%g' \ -e 's%(/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)/\([^/#).][^/#).]\)#\([a-zA-Z_-][0-9a-zA-Z_-]\))%(../../\1/\2/\3.md#\4)%g' \ -e 's%](\([^:.>)#][^:.>)#]\))%](../../\1.md)%g' \ -e 's%](\([^:.>)#][^:.>)#]\)#\([^:.>)#][^:.>)#]*\))%](../../\1.md#\2)%g' \ {} Related to https://github.com/flokoe/bash-hackers-wiki/issues/10 2024-01-29 02:07:56 +01:00			`substitution](../../syntax/expansion/intro.md)`
			`- [Quoting and escaping](../../syntax/quoting.md)`
Convert syntax pages to Markdown 2023-07-05 11:43:35 +02:00			`- [WordSplitting](http://mywiki.wooledge.org/WordSplitting),`
			`[IFS](http://mywiki.wooledge.org/IFS), and`
			`[DontReadLinesWithFor](http://mywiki.wooledge.org/DontReadLinesWithFor) -`
format(docs): remove escaped 's character pairs 2024-03-30 19:22:45 +01:00			`Greg's wiki`