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sed replacing specific characters and control characters by escaping

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# 8  
Old 05-02-2012
Another thing you could do is give a range of the characters you do want, then invert it with ^, and thus avoid specifying all possible nasty characters in the universe.

Code:
# Everything but alphanumerics and spaces replaced with _
echo "..." | sed 's/[^a-zA-Z0-9 \t]/_/g'

# 9  
Old 05-02-2012
Quote:
Originally Posted by ijustneeda
Wonder how fast tr is compared to sed on GB of text files?
Faster, certainly. tr is extremely simple, considering everything one character at a time instead of worrying about entire expressions. Far less work.

It also has no limitations on the size of lines for the same reason, while some versions of sed break on lines longer than 2000 bytes or so.
# 10  
Old 05-02-2012
The only problem might be if there are UTF-8 characters as tr cannot translate those AFAIK.
# 11  
Old 05-03-2012
By definition it can't since those are multi-byte sequences. It can certainly strip them out, though, since they're all values higher than ASCII 127.
Code:
tr -d '[\200-\377]' < input > output

This User Gave Thanks to Corona688 For This Post:
Scrutinizer
# 12  
Old 05-03-2012
I tried it, and like that it did not remove all characters, but like this it did:
Code:
LANG=C tr -d '[\200-\377]' < input > output

Code:
$ printf "%s\n" 'An preost wes on leoden, Laȝamon was ihoten
He wes Leovenağes sone -- liğe him be Drihten.
He wonede at Ernleȝe at æğelen are chirechen,
Uppen Sevarne staşe, sel şar him şuhte,
Onfest Radestone, şer he bock radde.' |
LANG=C tr -d '[\200-\377]'
An preost wes on leoden, Laamon was ihoten
He wes Leovenaes sone -- lie him be Drihten.
He wonede at Ernlee at elen are chirechen,
Uppen Sevarne stae, sel ar him uhte,
Onfest Radestone, er he bock radde.

Last edited by Scrutinizer; 05-03-2012 at 04:47 PM..
This User Gave Thanks to Scrutinizer For This Post:
Corona688
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