Re: Replace bits

perl -pe 's/^(..)H/${1}1/; s/^(.{7})L/${1}0/;' input > output
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The output is different on line 4, it prints

HH1HHHHH
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Explanation:

-p reads the file line by line; it prints the line after running the code on it
s/REGEX/STRING/ is substitution, it replaces what's matched by the regular expression REGEX by STRING
^ matches beginning of a line
. matches anything but newline
() create a "capture group", you can use $1 or ${1} to refer to the first capture group.

لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

Comment on Re: Replace bits Select or Download Code

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Re^2: Replace bits by newbiecali (Initiate) on Mar 30, 2015 at 23:30 UTC
can it take text file "file1.txt" and spit out the output in "output.txt" something like that	[reply]
Re^3: Replace bits by AnomalousMonk (Archbishop) on Mar 31, 2015 at 01:00 UTC
Exactly like that. Take `input` in choroba's command line above and replace it with `file1.txt` and replace `output` with `output.txt` likewise. Give a man a fish: `<%-(-(-(-<`	[reply] [d/l] [select]