Bug 263268

Summary:	bsdgrep: support empty subexpressions
Product:	Base System	Reporter:	Li-Wen Hsu <lwhsu>
Component:	bin	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Open ---
Severity:	Affects Only Me	CC:	emaste, kevans, wosch
Priority:	---
Version:	CURRENT
Hardware:	Any
OS:	Any
Bug Depends on:
Bug Blocks:	230332

Description Li-Wen Hsu freebsd_committer

2022-04-13 21:03:03 UTC

$ echo foo | egrep "|foo"
egrep: empty (sub)expression

more complex case: "^${user}(|[[:space:]]+.*)$"

Comment 1 Ed Maste freebsd_committer

2022-04-14 14:28:42 UTC

To address specific instances of this (before bsdgrep receives a change) one could also translate (|foo) to (foo)? e.g. "^${user}([[:space:]]+.*)?$"