Control characters

sandy1028 has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: Control characters by JavaFan (Canon) on Jun 05, 2009 at 12:28 UTC
Control characters are three stroke tokens, `\cA, \cB`, etc. You cannot put parts of the tokens and put them into a character class. Use: `s/[\cA-\cZ]+//g;` [download] or an equivalent `tr` construct. Note also that your use of `^` means you are only going to replace matches at the beginning of the string - at most one character in your example. Which from your description doesn't seem to be want you want.	[reply] [d/l] [select]
Re^2: Control characters by AnomalousMonk (Archbishop) on Jun 05, 2009 at 17:11 UTC
From the OP, it's not entirely clear (at least, to me) just what the OPer wants, but if all control characters are to be deleted, the substitution `s/[[:cntrl:]]+//g;` might better serve: the POSIX character class syntax responds to one or both (I forget which) of Unicode and locale variations. And, of course, the other point to make to the OPer is that the character set `[\cA-\cZ]` does not represent all control characters even in the ASCII character set.	[reply] [d/l] [select]
Re: Control characters by Anonymous Monk on Jun 05, 2009 at 12:08 UTC
Why don't you search? CR's and other control chars	[reply]
Re: Control characters by tbone1 (Monsignor) on Jun 05, 2009 at 15:18 UTC
I was going to suggest using regular expressions and the s/// command but the control characters make it rather tricky, since the ^ anchors a search at the beginning of a string. Quick and dirty, but maybe something like this? s/(.)?^O/\1/g; s/(.)?^N/\1/g; -- tbone1, YAPS (Yet Another Perl Schlub) And remember, if he succeeds, so what. - Chick McGee	[reply]
Re^2: Control characters by AnomalousMonk (Archbishop) on Jun 05, 2009 at 16:55 UTC
`s/(.)?^O/\1/g; s/(.)?^N/\1/g;` [download] But what do these statements really do? `>perl -wMstrict -le "for my $str (@ARGV) { printf q{%s -> }, $str; $str =~ s/(.)?^O/\1/g; $str =~ s/(.)?^N/\1/g; print $str; } " OhNoOhNo NotOnNotOn \1 better written as $1 at -e line 1. \1 better written as $1 at -e line 1. Use of uninitialized value $1 in substitution iterator at -e line 1. OhNoOhNo -> hNoOhNo Use of uninitialized value $1 in substitution iterator at -e line 1. NotOnNotOn -> otOnNotOn` [download]	[reply] [d/l] [select]