Bash Pattern matching and regular expressions Extended globbing
Example
2.02
Preparation
$ mkdir globbing
$ cd globbing
$ mkdir -p folder/{sub,another}folder/content/deepfolder/
touch macy stacy tracy "file with space" folder/{sub,another}folder/content/deepfolder/file .hiddenfile
$ shopt -u nullglob
$ shopt -u failglob
$ shopt -u dotglob
$ shopt -u nocaseglob
$ shopt -u extglob
$ shopt -u globstar
Bash's built-in extglob option can extend a glob's matching capabilities
shopt -s extglob
The following sub-patterns comprise valid extended globs:
?(pattern-list)– Matches zero or one occurrence of the given patterns*(pattern-list)– Matches zero or more occurrences of the given patterns+(pattern-list)– Matches one or more occurrences of the given patterns@(pattern-list)– Matches one of the given patterns!(pattern-list)– Matches anything except one of the given patterns
The pattern-list is a list of globs separated by |.
$ echo *([r-t])acy
stacy tracy
$ echo *([r-t]|m)acy
macy stacy tracy
$ echo ?([a-z])acy
macy
The pattern-list itself can be another, nested extended glob. In the above
example we have seen that we can match tracy and stacy with *(r-t).
This extended glob itself can be used inside the negated extended glob
!(pattern-list) in order to match macy
$ echo !(*([r-t]))acy
macy
It matches anything that does not start with zero or more occurrences of the
letters r, s and t, which leaves only macy as possible match.
