Re: input foo, output '[F|f][O|o][O|o]'?

[ZyX <kp-pav@xxxxxxxxx>]

02.07.13, 04:58, "TJ Luoma" <luomat@xxxxxxxxx>":
> 
> 
> On 1 Jul 2013, at 14:44, ZyX wrote:
> 
> > I do not think you will find a way to do this. All regex engines 
> > (precisely, programs that are using them) I know support a way to set 
> > case sensitivity for the whole regular expression and some support 
> > toggling this for a part of regular expression. In grep this is an -i 
> > switch, for vim it is either /i or \c/\C, for sed this is /i, for PCRE 
> > and perl this is additionally (?i) "atom" (additionally to other ways 
> > of toggling the behavior which are highly dependent on programs 
> > embedding PCRE; for perl this is usual /i flag). Even zsh globs do 
> > support (#i).
> 
> Phil Pennock's version worked great:
> 
> % foo=CrashPlan
> % for c in ${(s::)foo}; do print -n "[${(U)c}|${(L)c}]";done; print
> [C|c][R|r][A|a][S|s][H|h][P|p][L|l][A|a][N|n]
> %

This is a bicycle. You asked for a standard way, you will not find it.

> 
> 
> > By the way, what regex engine is your output for? Any I am aware of 
> > parse "[N|n]" as "either one of three characters: N, n, or pipe".
> 
> Really? I can think of several that support it. Maybe it's because I'm 
> old enough to remember when a lot of these utilities didn't have 'ignore 
> case'
> 
> % echo "foo\nbar\nbat" | egrep -v '[F|f]'
> bar
> bat
> 
> % echo "foo\nbar\nbat" | sed 's#[F|f][O|o][O|o]#XXX#g'
> XXX
> bar
> bat
> 
> You can also use it for matching case/esac :
> 
> case "$i" in
> 	[C|c][R|r][A|a][S|s][H|h][P|p][L|l][A|a][N|n])
> 			echo "matched crashplan"
> 	;;
> 
> 	*)
> 			echo "No Match"
> 	;;
> 
> esac

It is not a disproof. Check it with pipe symbol in input.

> 
> 
> > I am also assuming XY problem here: what for do you need such 
> > conversion? You should consider lowercasing the tested string if 
> > nothing like -i is available.
> 
> It's for use with the AddDescription directive for .htaccess which (from 
> what I understand) takes its case sensitivity from the underlying 
> filesystem when matching filenames. There's no "ignore case" flag or 
> anything else that I can use with it, so my only option (at least, the 
> only one I can think of) is the one that I suggested. For example, if I 
> wanted to add this for any files which start with 'BBEdit' (case 
> insensitive) this is what I'd need to use:
> 
> 	AddDescription "<a href='http://barebones.com/bbedit'>A text editor 
> that doesn't suck</a>" [B|b][B|b][E|e][D|d][I|i][T|t]*
> 
> I verified that it works, but typing that stuff manually is tedious and 
> highly error prone, which made it the perfect place for a shell script 
> :-)

Unless AddDescription uses different regex engine then FilesMatch answer is in the first link if searching for "htaccess case insensitive regex": (?i:pattern).