shell-style pattern matching
Globbing characters (wildcards) are special characters used to
perform pattern matching of pathnames and command arguments in the
csh(1), ksh(1), and
shells as well as the C library functions
glob(3). A glob pattern is a word containing one or more unquoted
*’ characters, or
Globs should not be confused with the more powerful regular expressions used by programs such as grep(1). While there is some overlap in the special characters used in regular expressions and globs, their meaning is different.
The pattern elements have the following meaning:
- Matches any single character.
- Matches any sequence of zero or more characters.
- Matches any of the characters inside the brackets. Ranges of characters
can be specified by separating two characters by a
-’ (e.g. “[a0-9]” matches the letter ‘a’ or any digit). In order to represent itself, a ‘
-’ must either be quoted or the first or last character in the character list. Similarly, a ‘
]’ must be quoted or the first character in the list if it is to represent itself instead of the end of the list. Also, a ‘
!’ appearing at the start of the list has special meaning (see below), so to represent itself it must be quoted or appear later in the list.
Within a bracket expression, the name of a character class enclosed in ‘[:’ and ‘:]’ stands for the list of all characters belonging to that class. Supported character classes:
cntrl lower space
graph punct xdigit
These match characters using the macros specified in isalnum(3), isalpha(3), and so on. A character class may not be used as an endpoint of a range.
- Like [..], except it matches any character not inside the brackets.
- Matches the character following it verbatim. This is useful to quote the
special characters ‘
[’, and ‘
\’ such that they lose their special meaning. For example, the pattern “\\\*\[x]\?” matches the string “\*[x]?”.
Note that when matching a pathname, the path separator
/’, is not matched by a
*’, character or by a
“[..]” sequence. Thus, /usr/*/*/X11
would match /usr/X11R6/lib/X11 and
/usr/*/X11 would not match either. Likewise,
/usr/*/bin would match
/usr/local/bin but not
fnmatch(3), glob(3), re_format(7)
In early versions of UNIX, the shell did not do pattern expansion itself. A dedicated program, /etc/glob, was used to perform the expansion and pass the results to a command. In Version 7 AT&T UNIX, with the introduction of the Bourne shell, this functionality was incorporated into the shell itself.