MPE/iX Shell and Utilities Reference Manual, Vol 2

regexp(3) MPE/iX Shell and Utilities regexp(3)

a) If the initial character is a circumﬂex ˆ, then this bracket expression is com-

plemented. It shall match any character or collating-element except for the

expressions speciﬁed in the bracket expression. For pattern matching, as

performed by the fnmatch() function, this initial character is instead !

(the exclamation mark).

b) If the ﬁrst character after any potential circumﬂex is either a dash (-), or a

closing square bracket (]), then that character shall match exactly that char-

acter; that is a literal dash or closing square bracket.

c) Collating sequences may be speciﬁed by enclosing their name inside square

bracket period. For example, [.ch.] matches the multi-character collat-

ing sequence ch (if the current language supports that collating sequence).

Any single character is itself. It is an error to give a collating sequence that

isn’t part of the current locale.

d) Equivalence classes may be speciﬁed by enclosing a character or collating

sequence inside square bracket equals. For example, [=a=] matches any

character in the same equivalence class as a. This normally expands to all

the variants of a in the current locale: for example, a, \(a:, \(a‘, ... On

some locales it might include both the uppercase and lowercase of a given

character. In the

POSIX locale, this always expands to only the character

given.

e) Within a character class expression (one made with square brackets), the

following constructs may be used to represent sets of characters. These con-

structs are used for internationalization and handle the different collating se-

quences as required by

POSIX.

[:alpha:] Any alphabetic character.

[:lower:] Any lowercase alphabetic character.

[:upper:] Any uppercase alphabetic character.

[:digit:] Any digit character.

[:alnum:] Any alphanumeric character (alphabetic or digit).

[:space:] Any white space character (blank, horizontal tab, vertical

tab).

[:graph:] Any printable character, except the blank character.

[:print:] Any printable character, including the blank character.

Miscellaneous Information 3-33