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Re: tr problem



Gene Heskett wrote:


I'm trying to convert a test file, src code for a legacy computer, whose
eol is a single cr into one with a newline subbed for each cr, and tr is
being a pita, it broken, or there is PEBKAC.

If I use this syntax:

tr -c \r \n <filename  >filename2

Then the whole file is converted to nnnnnnnnnn's, every byte.

The manpage (and pinfo tr too) is, shall we say, completely lacking in how
to handle the file I/O.

So how do you use tr?"
Why option -c?

tr '\r' '\n' <filename  >filename2
would do it.

Cuz the manpage says that it triggers the character convert thing?

No, tr actually takes 2 'sets' of characters even though in your use you only need one character in each set. For example
tr '[A-Z]' '[a-z]'
would lowercase a file (and the brackets and quotes aren't strictly necessary but would be on a sysV version). The -c option means to complement the first set (i.e. it becomes the characters not included).

It doesn't touch on its performance if the option isn't given. And it doesn't mention using the quotes either, but it worked just fine, thank you very much.

Man pages generally never mention the things the shell does to a command line before starting the program. This will include expanding variables and wildcard filenames, redirecting I/O, and other things triggered by shell metacharacters. In this case tr doesn't particularly need the quotes, but if you don't use them the shell will parse and remove the \ characters (treating them as quotes for the following character in its own parsing). These details are the same for every command you type (or script) and not repeated in every man page.

--
  Les Mikesell
   lesmikesell gmail com



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