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Pathname Expansion

After word splitting, unless the -f option has been set, bash scans each word for the characters .BR * , .BR ? , and .BR [ . If one of these characters appears, then the word is regarded as a .IR pattern , and replaced with an alphabetically sorted list of file names matching the pattern. If no matching file names are found, and the shell option nullglob is disabled, the word is left unchanged. If the nullglob option is set, and no matches are found, the word is removed. If the shell option nocaseglob is enabled, the match is performed without regard to the case of alphabetic characters. When a pattern is used for pathname expansion, the character ``.'' at the start of a name or immediately following a slash must be matched explicitly, unless the shell option dotglob is set. When matching a pathname, the slash character must always be matched explicitly. In other cases, the ``.'' character is not treated specially. See the description of shopt below under .SM SHELL BUILTIN COMMANDS for a description of the .BR nocaseglob , .BR nullglob , and dotglob shell options.

The .SM GLOBIGNORE shell variable may be used to restrict the set of file names matching a .IR pattern . If .SM GLOBIGNORE is set, each matching file name that also matches one of the patterns in .SM GLOBIGNORE is removed from the list of matches. The file names ``.'' and ``..'' are always ignored, even when .SM GLOBIGNORE is set. However, setting .SM GLOBIGNORE has the effect of enabling the dotglob shell option, so all other file names beginning with a ``.'' will match. To get the old behavior of ignoring file names beginning with a .BR ``.'' , make ``.*'' one of the patterns in .SM .BR GLOBIGNORE . The dotglob option is disabled when .SM GLOBIGNORE is unset.

Pattern Matching\fP

Any character that appears in a pattern, other than the special pattern characters described below, matches itself. The NUL character may not occur in a pattern. The special pattern characters must be quoted if they are to be matched literally.

The special pattern characters have the following meanings:

*

Matches any string, including the null string.

?

Matches any single character.

[...]

Matches any one of the enclosed characters. A pair of characters separated by a minus sign denotes a .IR range ; any character lexically between those two characters, inclusive, is matched. If the first character following the [ is a ! or a ^ then any character not enclosed is matched. A - may be matched by including it as the first or last character in the set. A ] may be matched by including it as the first character in the set.
.if t .sp 0.5 .if n .sp 1 Within [ and .BR ] , character classes\fP can be specified using the syntax [:\fPclass\fP:]\fP, where class\fP is one of the following classes defined in the POSIX.2 standard:

.if n alnum alpha ascii blank cntrl digit graph lower print punct space upper xdigit .if t alnum alpha ascii blank cntrl digit graph lower print punct space upper xdigit
A character class matches any character belonging to that class.
.if t .sp 0.5 .if n .sp 1 Within [ and .BR ] , an equivalence class\fP can be specified using the syntax [=\fPc\fP=]\fP, which matches all characters with the same collation weight (as defined by the current locale) as the character c\fP.
.if t .sp 0.5 .if n .sp 1 Within [ and .BR ] , the syntax [.\fPsymbol\fP.]\fP matches the collating symbol symbol\fP.

If the extglob\fP shell option is enabled using the shopt\fP builtin, several extended pattern matching operators are recognized. In the following description, a pattern-list\fP is a list of one or more patterns separated by a |\fP. Composite patterns may be formed using one or more of the following sub-patterns: .sp 1

?(\fP\^pattern-list\^\fP)\fP

Matches zero or one occurrence of the given patterns

*(\fP\^pattern-list\^\fP)\fP

Matches zero or more occurrences of the given patterns

+(\fP\^pattern-list\^\fP)\fP

Matches one or more occurrences of the given patterns

@(\fP\^pattern-list\^\fP)\fP

Matches exactly one of the given patterns

!(\fP\^pattern-list\^\fP)\fP

Matches anything except one of the given patterns

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