Linux in a Nutshell, Fifth Edition

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Chapter 6: The Bash Shell and Korn Shell

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

This pattern can be a sequence of patterns separated by |, meaning that the match

applies to any of the patterns. This extended syntax resembles that available in

egrep and awk. In the Korn shell, but not in Bash, if & is used instead of |, all the

patterns must match. & has higher precedence than |.

ksh93 and Bash support the POSIX [[=c=]] notation for matching characters that

have the same weight, and [[.c.]] for specifying collating sequences. In addition,

character classes, of the form [[:class:]], allow you to match the following classes

of characters.

Bash and ksh93 also accept the [:word:] character class, which is not in POSIX.

[[:word:]] is equivalent to [[:alnum:]_].

Examples

$ ls new* List new and new.1

$ cat ch? Match ch9 but not ch10

$ vi [D-R]* Match files that begin with uppercase D through R

$ pr !(*.o|core) | lp Print files that are not object files or core dumps

On modern systems, ranges such as [D-R] are not portable; the sys-

tem’s locale may include more than just the uppercase letters from

D to R in the range.

Quoting

Quoting disables a character’s special meaning and allows it to be used literally, as

itself. The following table displays characters that have special meaning to the

Bash and Korn shells.

Class Characters matched ...