UNIX for Dummies Questions & Answers

Hello every1.

Can any1 help me with the col command.

Wat is a reverse line feed.

Which kind of files u need to use the col command.

Well if a linefeed puts you on the next line, a reverse linefeed puts you on the preceding line.

As the man page says, col is used with nroff. nroff can do some silly things. Let's say you're line number one and you want to print two lines worth of stuff. You would just print some stuff for line one. Then a newline character puts you on the next line. And finally you print some more stuff for line two. Nroff does not always work line that. First it prints a few characters on line one. Then it goes to line two and prints a few characters. Then back to line one and print a few more. And it can go back and forth many times. col catches all of this. It completely assembles a line and then prints it. That is much faster.

Mostly I use col with man. If you do "man cat > file", file will not be super readable. "man cat | col -b > file" will be perfect.

Hi All,

I am talking about unix col(1) command used for some reverse line filtering etc.
And I notice that the stdout of this command is line buffered i.e. the stdout will flush the data in its buffer line by line. So the number of writes performed by stdout are more.

So now if I make stdout as fully buffered it will reduce the write hits.

But if I do these changes I think there will some problems
-> when slow terminals use col(1) as command , then the turn around time will get reduce for it self.
eg: cat file | col -b | lp
Here lp will receive data in terms of buffer size but before it was receving in terms of each lines.

So can I change change col(1) command's stdout to fully buffered?

So do any of you know some more problems related with this change , and can I see some link about col(1) command design stating that it should be either line buffered or fully buffered etc.


Waiting for positive replay,
Sunil kumar.



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Thanks & Regards,

Sunil Kumar S