reverse cat text file

methods

1. tac

   1. install on mac

       $ brew install coreutils
       ==> Downloading https://ftp.gnu.org/gnu/coreutils/coreutils-8.30.tar.xz
       ######################################################################## 100.0%
       ==> ./configure --prefix=/usr/local/Cellar/coreutils/8.30 --program-prefix=g --without-gmp
       ==> make install
       ==> Caveats
       All commands have been installed with the prefix 'g'.
      
       If you really need to use these commands with their normal names, you
       can add a "gnubin" directory to your PATH from your bashrc like:
      
           PATH="/usr/local/opt/coreutils/libexec/gnubin:$PATH"
      
       Additionally, you can access their man pages with normal names if you add
       the "gnuman" directory to your MANPATH from your bashrc as well:
      
           MANPATH="/usr/local/opt/coreutils/libexec/gnuman:$MANPATH"
      
       ==> Summary
       🍺  /usr/local/Cellar/coreutils/8.30: 430 files, 8.8MB, built in 4 minutes 26 seconds
      

   2. create a link

       $ ln -s /usr/local/bin/gtac /usr/local/bin/tac
      

2. cat

   1. use -r

       $ cat -r file.txt
      

3. sed

   1. use cat -n

       $ cat -n file.txt | grep needle
      
       11344 sth bla bla needle bla bla sth
      

   2. use sed -n

       $ sed -n 11344,11444p file.txt
       ...