Chet Ramey wrote:
On 9/27/11 6:41 PM, Roger wrote:
Correct. After reading the entire Bash Manual page, I didn't see much mention
of documentation resources (of ERE) besides maybe something about egrep from
Bash's Manual Page or elsewhere on the web. After extensive research for
regex/regexpr, only found Perl Manual Pages.
Might be worth mentioning a link or good reference for this ERE within the Bash
Manual (Page)?
The bash man page refers to regex(3). On my BSD (Mac OS X) system, that
refers to re_format(7), which documents the BRE and ERE regular expression
formats. On an Ubuntu box, to choose a representative Linux example, that
refers to regex(7), which contains the same explanation, and the GNU regex
manual. This sort of "chained" man page reference is common.
If you like info, `info regex' on a Linux box should display both pages.
---
If the poor guy looked at the pages you suggest,
he'd see various examples showing:
An atom is a regular expression enclosed in "()"
A bracket expression is a list of characters enclosed in "[]"
To use a literal
'-' as the first endpoint of a range, enclose it in "[." and ".]"For
example, if o
and ^ are the members of an equivalence class, then "[[=o=]]",
"[[=^=]]", and "[o^]" are all synonymous.ents. A
null string is considered longer than no match at all. For example,
"bb*" matches the three middle characters of "abbbc",
"(wee|week)(knights|nights)" matches all ten characters of "week‐
nights", when "(.*).*" is matched against "abc" the parenthesized sub‐
expression matches all three characters, and when "(a*)*" is matched
against "bc" both the whole RE and the parenthesized subexpression
match the null string.
