Write down the commands that can do the following tasks: Find out how many lines are there in the output of 'man -k read' Hint: 'we' and pipeline a) b) Find out how many words are there in the file 'direnth Hint 1: The file is located at /usr/include/dirent.h Hint 2: Use 'cat' (or 'more', less') and pipeline to 'wo' Change the mode (the permission of a file) c) Hint: Search the manual for "change mode