GNU Info

(bashref.info)Word Splitting

---

Next: Filename Expansion Prev: Process Substitution Up: Shell Expansions

---

Enter node , (file) or (file)node

Word Splitting
--------------

   The shell scans the results of parameter expansion, command
substitution, and arithmetic expansion that did not occur within double
quotes for word splitting.

   The shell treats each character of `$IFS' as a delimiter, and splits
the results of the other expansions into words on these characters.  If
`IFS' is unset, or its value is exactly `<space><tab><newline>', the
default, then any sequence of `IFS' characters serves to delimit words.
If `IFS' has a value other than the default, then sequences of the
whitespace characters `space' and `tab' are ignored at the beginning
and end of the word, as long as the whitespace character is in the
value of `IFS' (an `IFS' whitespace character).  Any character in `IFS'
that is not `IFS' whitespace, along with any adjacent `IFS' whitespace
characters, delimits a field.  A sequence of `IFS' whitespace
characters is also treated as a delimiter.  If the value of `IFS' is
null, no word splitting occurs.

   Explicit null arguments (`""' or `''') are retained.  Unquoted
implicit null arguments, resulting from the expansion of parameters
that have no values, are removed.  If a parameter with no value is
expanded within double quotes, a null argument results and is retained.

   Note that if no expansion occurs, no splitting is performed.