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What is extended glob?
Extended globs gives us more of the power of regular expressions for globbing. Unlike character sets or character classes, patterns can be more than one character and we can match multiple occurrences of a pattern.
What is Extglob in Linux?
Enter extglob . As you can guess, it stands for extended globbing . This option allows for more advanced pattern matching. From man bash : extglob If set, the extended pattern matching features described above under Pathname Expansion are enabled.
What is a Globstar?
Bash version 4.0 adds a new globbing option called globstar which treats the pattern ** differently when it’s set. Normally, if you use the pattern ** on the command line it acts the same as the * pattern.
How does glob work in Bash?
The Bash shell feature that is used for matching or expanding specific types of patterns is called globbing. Globbing is mainly used to match filenames or searching for content in a file. Globbing uses wildcard characters to create the pattern.
Which is the best syntax for Extended Globbing?
However, probably the most interesting extended globbing syntax is the “! (…)” syntax for matching everything except (ie not matching). But, be careful, this doesn’t always do what you might expect. For example, let’s list all the files that aren’t JPEGs or GIFs. One’s first thought might be something like this:
How to Glob files with Bash Extended Globbing?
To list all the files that match the regular expression “ab (2|3)+.jpg” you could do: Now that’s something you can’t do with regular globbing. Note: this matches files like ab2.jpg, ab3.jpg, ab2222.jpg, ab333.jpg, etc.
Can a glob be used to combine multiple file types?
The idea can be extended to more file extensions, but you have to check that the combinations won’t match any other unwanted file extension you may have on those folders. So, be careful with this. To automatically combine an arbitrary list of extensions into a single glob pattern, you can do the following:
How is globbing different from LS read *.TXT?
That’s different from ls read*.txt, which will match both readme.txt and read.txt, because the asterisk means “zero or more characters” in the file glob. Here’s the easy way to remember if you’re using globbing (which is very simple) vs. regular expressions: globbing is done to filenames by the shell, and regex is used for searching text.