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re.format.7:

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Replaced "\(dg" with "***"; neither the current GNO nroff program
	nor groff used by Linux (on which the web versions of the man
	pages is generated) use "\(dg", which is supposed to be a dagger.
This commit is contained in:
gdr-ftp 1998-04-16 05:52:39 +00:00
parent e8bcb53ed7
commit e2c6df7488
1 changed files with 17 additions and 15 deletions
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32
usr.man/man7/re.format.7
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@ -35,6 +35,8 @@
.\" .\"
.\" @(#)re_format.7 8.3 (Berkeley) 3/20/94 .\" @(#)re_format.7 8.3 (Berkeley) 3/20/94
.\" .\"
.\" $Id: re.format.7,v 1.3 1998/04/16 05:52:39 gdr-ftp Exp $
.\"
.TH RE_FORMAT 7 "7 October 1997" GNO "Miscellaneous" .TH RE_FORMAT 7 "7 October 1997" GNO "Miscellaneous"
.SH NAME .SH NAME
re_format \- POSIX 1003.2 regular expressions re_format \- POSIX 1003.2 regular expressions
@ -50,18 +52,18 @@ and obsolete REs (roughly those of
Obsolete REs mostly exist for backward compatibility in some old programs; Obsolete REs mostly exist for backward compatibility in some old programs;
they will be discussed at the end. they will be discussed at the end.
1003.2 leaves some aspects of RE syntax and semantics open; 1003.2 leaves some aspects of RE syntax and semantics open;
`\(dg' marks decisions on these aspects that `***' marks decisions on these aspects that
may not be fully portable to other 1003.2 implementations. may not be fully portable to other 1003.2 implementations.
.PP .PP
A (modern) RE is one\(dg or more non-empty\(dg \fIbranches\fR, A (modern) RE is one*** or more non-empty*** \fIbranches\fR,
separated by `|'. separated by `|'.
It matches anything that matches one of the branches. It matches anything that matches one of the branches.
.PP .PP
A branch is one\(dg or more \fIpieces\fR, concatenated. A branch is one*** or more \fIpieces\fR, concatenated.
It matches a match for the first, followed by a match for the second, etc. It matches a match for the first, followed by a match for the second, etc.
.PP .PP
A piece is an \fIatom\fR possibly followed A piece is an \fIatom\fR possibly followed
by a single\(dg `*', `+', `?', or \fIbound\fR. by a single*** `*', `+', `?', or \fIbound\fR.
An atom followed by `*' matches a sequence of 0 or more matches of the atom. An atom followed by `*' matches a sequence of 0 or more matches of the atom.
An atom followed by `+' matches a sequence of 1 or more matches of the atom. An atom followed by `+' matches a sequence of 1 or more matches of the atom.
An atom followed by `?' matches a sequence of 0 or 1 matches of the atom. An atom followed by `?' matches a sequence of 0 or 1 matches of the atom.
@ -70,7 +72,7 @@ A \fIbound\fR is `{' followed by an unsigned decimal integer,
possibly followed by `,' possibly followed by `,'
possibly followed by another unsigned decimal integer, possibly followed by another unsigned decimal integer,
always followed by `}'. always followed by `}'.
The integers must lie between 0 and RE_DUP_MAX (255\(dg) inclusive, The integers must lie between 0 and RE_DUP_MAX (255***) inclusive,
and if there are two of them, the first may not exceed the second. and if there are two of them, the first may not exceed the second.
An atom followed by a bound containing one integer \fIi\fR An atom followed by a bound containing one integer \fIi\fR
and no comma matches and no comma matches
@ -84,19 +86,19 @@ a sequence of \fIi\fR through \fIj\fR (inclusive) matches of the atom.
.PP .PP
An atom is a regular expression enclosed in `()' (matching a match for the An atom is a regular expression enclosed in `()' (matching a match for the
regular expression), regular expression),
an empty set of `()' (matching the null string)\(dg, an empty set of `()' (matching the null string)***,
a \fIbracket expression\fR (see below), `.' a \fIbracket expression\fR (see below), `.'
(matching any single character), `^' (matching the null string at the (matching any single character), `^' (matching the null string at the
beginning of a line), `$' (matching the null string at the beginning of a line), `$' (matching the null string at the
end of a line), a `\e' followed by one of the characters end of a line), a `\e' followed by one of the characters
`^.[$()|*+?{\e' `^.[$()|*+?{\e'
(matching that character taken as an ordinary character), (matching that character taken as an ordinary character),
a `\e' followed by any other character\(dg a `\e' followed by any other character***
(matching that character taken as an ordinary character, (matching that character taken as an ordinary character,
as if the `\e' had not been present\(dg), as if the `\e' had not been present***),
or a single character with no other significance (matching that character). or a single character with no other significance (matching that character).
A `{' followed by a character other than a digit is an ordinary A `{' followed by a character other than a digit is an ordinary
character, not the beginning of a bound\(dg. character, not the beginning of a bound***.
It is illegal to end an RE with `\e'. It is illegal to end an RE with `\e'.
.PP .PP
A \fIbracket expression\fR is a list of characters enclosed in `[]'. A \fIbracket expression\fR is a list of characters enclosed in `[]'.
@ -108,7 +110,7 @@ If two characters in the list are separated by `\-', this is shorthand
for the full \fIrange\fR of characters between those two (inclusive) in the for the full \fIrange\fR of characters between those two (inclusive) in the
collating sequence, collating sequence,
e.g. `[0-9]' in ASCII matches any decimal digit. e.g. `[0-9]' in ASCII matches any decimal digit.
It is illegal\(dg for two ranges to share an It is illegal*** for two ranges to share an
endpoint, e.g. `a-c-e'. endpoint, e.g. `a-c-e'.
Ranges are very collating-sequence-dependent, Ranges are very collating-sequence-dependent,
and portable programs should avoid relying on them. and portable programs should avoid relying on them.
@ -142,7 +144,7 @@ of all collating elements equivalent to that one, including itself.
the treatment is as if the enclosing delimiters were `[.' and `.]'.) the treatment is as if the enclosing delimiters were `[.' and `.]'.)
For example, if o and \o'o^' are the members of an equivalence class, For example, if o and \o'o^' are the members of an equivalence class,
then `[[=o=]]', `[[=\o'o^'=]]', and `[o\o'o^']' are all synonymous. then `[[=o=]]', `[[=\o'o^'=]]', and `[o\o'o^']' are all synonymous.
An equivalence class may not\(dg be an endpoint An equivalence class may not*** be an endpoint
of a range. of a range.
.PP .PP
Within a bracket expression, the name of a \fIcharacter class\fR enclosed Within a bracket expression, the name of a \fIcharacter class\fR enclosed
@ -164,7 +166,7 @@ These stand for the character classes defined in
A locale may provide others. A locale may provide others.
A character class may not be used as an endpoint of a range. A character class may not be used as an endpoint of a range.
.PP .PP
There are two special cases\(dg of bracket expressions: There are two special cases*** of bracket expressions:
the bracket expressions `[[:<:]]' and `[[:>:]]' match the null string at the bracket expressions `[[:<:]]' and `[[:>:]]' match the null string at
the beginning and end of a word respectively. the beginning and end of a word respectively.
A word is defined as a sequence of A word is defined as a sequence of
@ -214,7 +216,7 @@ When it appears inside a bracket expression, all case counterparts
of it are added to the bracket expression, so that (e.g.) `[x]' of it are added to the bracket expression, so that (e.g.) `[x]'
becomes `[xX]' and `[^x]' becomes `[^xX]'. becomes `[xX]' and `[^x]' becomes `[^xX]'.
.PP .PP
No particular limit is imposed on the length of REs\(dg. No particular limit is imposed on the length of REs***.
Programs intended to be portable should not employ REs longer Programs intended to be portable should not employ REs longer
than 256 bytes, than 256 bytes,
as an implementation can refuse to accept such REs and remain as an implementation can refuse to accept such REs and remain
@ -228,9 +230,9 @@ with `{' and `}' by themselves ordinary characters.
The parentheses for nested subexpressions are `\e(' and `\e)', The parentheses for nested subexpressions are `\e(' and `\e)',
with `(' and `)' by themselves ordinary characters. with `(' and `)' by themselves ordinary characters.
`^' is an ordinary character except at the beginning of the `^' is an ordinary character except at the beginning of the
RE or\(dg the beginning of a parenthesized subexpression, RE or*** the beginning of a parenthesized subexpression,
`$' is an ordinary character except at the end of the `$' is an ordinary character except at the end of the
RE or\(dg the end of a parenthesized subexpression, RE or*** the end of a parenthesized subexpression,
and `*' is an ordinary character if it appears at the beginning of the and `*' is an ordinary character if it appears at the beginning of the
RE or the beginning of a parenthesized subexpression RE or the beginning of a parenthesized subexpression
(after a possible leading `^'). (after a possible leading `^').