Pattern Matching

Operator Meaning

* Matches any string including the null.

? Matches single character

[a-Z] Matches case insensitive letters a - z

[0-9a-Z] Matches case insensitive letters and numbers

**/* Matches all files and zero or more directories and subdirectories

**/** Matches only directories and subdirectories

Posix Classes

Operator Meaning

[[:alnum:]] matches alphabetic or numeric characters. This is equivalent to [A-Za-z0-9]

[[:alpha:]] matches alphabetic characters. This is equivalent to [A-Za-z]

[[:space:]] matches whitespace characters (space and horizontal tab)

[[:cntrl:]] matches control characters

[[:digit:]] matches (decimal) digits. This is equivalent to [0-9]

[[:lower:]] matches lowercase alphabetic characters. This is equivalent to [a-z]

[[:print:]] Matches characters in the range of ASCII 32 – 126 (printable characters)

[[:upper:]] matches uppercase alphabetic characters. This is equivalent to [A-Z]

[[:xdigit:]] matches hexadecimal digits. This is equivalent to [0-9A-Fa-f]

ls [[:digit:]]

grep [[:digit:]] test.file

Extended Pattern Matching

Operator Meaning

*(pattern) Matches zero or more occurrences of the given pattern

+(pattern) Matches one or more occurrences of the given pattern

?(pattern) Matches zero or one occurrence of the given pattern

@(pattern) Matches exaclty one of the given pattern

!(pattern) Matches anything except one of the given pattern

ls -d !(*.html|*gif|*jpg) # everything but .html, .jpg or ,gif files

ls file+([0-9])

# list file9, file22 but not fileit

ls -d +(apl*|un*)

# begins with apl or un only