Unix: removing duplicates from a file

Over the last few months, I have re-discovered some unix commands (it’s been such a long time)

  • Eliminate duplicate lines from a file

#sort -u filename > filename.new

  • List all lines that do not match a condition

#grep -v ajsk filename

  • Copy contents of two files to one

#cat file1 file2 > file3

  • Append output of a command to a file

#cat file1 >> file2