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.
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