man 7 glob
Glob Patterns: Globbing Pathnames
Long ago, in Unix V6, the was a program /etc/glob that would expand wildcard patterns.Soon it was built into shell and bash.
Glob (Wildcard) Matching
A string is a wildcard pattern if it contains one of the characters:
? * [
Globbing is the operation that expands a wildcard pattern into the list of pathnames matching the pattern.
? (not between brackets) matches any single character.
* (not between brackets) matches any string, including empty string.
Glob Patterns Character Classes
[abc]: matches any single character enclosed in the brackets (either a, b or c). The string enclosed cannot be empty hence ']' can be allowed between the brackets.
Glob Patterns Ranges
[a-z]: Two characters separated by a '-' denote a range.
[A-Fa-f0-9] denote [ABCDEFabcdef0123456789].
Glob Patterns Complementation
[!a-f]: matches a single character that is not matched by removing the first'!'. ie. The negation.
[!]a-]: matches all single characters except ']', 'a', '-'
Glob Patterns removing the special meaning
You can remove the special meaning of:
? * [ \
By preceding with a backslash, or if it is a shell command enclose in quotes.
Globbing is applied to each part of a path name seperately, the delimiter being '/'. The backslash cannot be matched by '?' or '*'.
If a filename starts with '.' It needs to be matched explicitly as `rm *` will not remove .profile.
Glob Patterns are Not Regular Expressions
They are similar however
- Glob patterns match filenames not text
- Conventions are not the same (regular expressions: '*' means 0 or more of the preceding thing.
- Regular expressions use '^' as negation, POSIX defines '^' as undefined.
More on Gitignore type:
git help gitignore