1.6 KiB
====== Word splitting ======
FIXME to be continued!
Word splitting occurs once any of the following expansions are done (and only then!)
- Parameter expansion
- Command substitution
- Arithmetic expansion 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
- <space>
- <tab>
- <newline> 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 >>nothing<<) is found, it is removed, unless it is quoted (''<nowiki>''</nowiki>'' or ''""'').
Again note: Without any expansion beforehand, Bash won't perform word splitting! In this case, the initial token parsing is solely responsible.
===== See also =====