standards/54410: one-true-awk not POSIX compliant (no extended REs)

Jens Schweikhardt schweikh at
Sat Jul 12 03:40:11 PDT 2003

>Number:         54410
>Category:       standards
>Synopsis:       one-true-awk not POSIX compliant (no extended REs)
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-standards
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jul 12 03:40:09 PDT 2003
>Originator:     Jens Schweikhardt
>Release:        FreeBSD 5.1-CURRENT i386
Digital Details
System: FreeBSD 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Wed Jul 9 21:22:46 CEST 2003 toor at i386

	Our /usr/bin/awk understands only basic RE, not Extended RE, as
	required by IEEE Std 1003.1-2001:


<quote std="IEEE Std 1003.1-2001" section=awk>
Regular Expressions

The awk utility shall make use of the extended regular expression
notation (see the Base Definitions volume of IEEE Std 1003.1-2001,
Section 9.4, Extended Regular Expressions)

<quote std="IEEE Std 1003.1-2001" section=ere>
EREs Matching Multiple Characters
5. When an ERE matching a single character or an ERE enclosed in
parentheses is followed by an interval expression of the format "{m}" ,
"{m,}" , or "{m,n}" , together with that interval expression it shall
match what repeated consecutive occurrences of the ERE would match. The
values of m and n are decimal integers in the range 0 <= m<= n<=
{RE_DUP_MAX}, where m specifies the exact or minimum number of
occurrences and n specifies the maximum number of occurrences. The
expression "{m}" matches exactly m occurrences of the preceding ERE,
"{m,}" matches at least m occurrences, and "{m,n}" matches any number of
occurrences between m and n, inclusive.

	echo e | /usr/bin/awk '/e{1}/'          # should print e, but prints nothing


	It's probaly POLA violation to change the default RE style from
	BRE to ERE, but we should add a POSIX mode that uses BRE (e.g.
	gawk needs --posix to be compliant).


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