How to reverse the contents of a file? - Page 2 - UNIX for Advanced & Expert Users

vgersh99 · #8 (**permalink**) 06-05-2007

attached is a compilation of different methods.

praveenkumar_l · #9 (**permalink**) 06-06-2007

Quote:

Originally Posted by aajan

Hi Guys,
Am new to this forum .... And also to shell scripting

I need a k-shell script to reverse the contents of a file...

Please come up with the solutions...

With regards,
Anand

By reverse, you mean character by character or line by line?

ShawnMilo · #10 (**permalink**) 05-16-2008

Try playing with the -r flag on tail.

era · #11 (**permalink**) 05-17-2008

Just out of curiosity, you can use shell constructs for this, too.

Code:

#!/bin/sh

tac () {
  local line
  if read line; then
    tac
    printf '%s\n' "$line"
  fi
}

for f; do
  tac <"$f"
done

ksh could use print instead of printf; tested with bash. (Using echo is not very robust, but would be compatible even with the earliest Bourne shells. But then, local is a fairly recent addition, isn't it?)

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