GLOB(7) | Miscellaneous Information Manual | GLOB(7) |
glob
— 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
sh(1) shells as well as the C
library functions fnmatch(3)
and glob(3). A glob pattern is
a word containing one or more unquoted
‘?
’ or
‘*
’ characters, or
“[..]” sequences.
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:
-
’ (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:
alnum |
cntrl | lower | space |
alpha |
digit | upper | |
blank |
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.
?
’,
‘*
’,
‘[
’, 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
‘?
’, or
‘*
’, character or by a
“[..]” sequence. Thus, /usr/*/*/X11
would match /usr/X11R6/lib/X11 and
/usr/X11R6/include/X11 while
/usr/*/X11 would not match either. Likewise,
/usr/*/bin would match
/usr/local/bin but not
/usr/bin.
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.
January 25, 2019 | OpenBSD-6.6 |