Shell: Day #2
Today run through the commands to process the Text streams from the shell.
- less – command let you show less content from the file you are viewing.
- sort – helps you sort the output, -f let you do sort case-insensitive and -n numerical sort.
- cut – help to select the fields(-f)/character(-c)
- fmt – format the output of the file, you can specify the width with -w
- tac – similar to the cat command but in reverse
- sed- this command use to process each line of file with a script
let see these command in action
>> less hello.txt Hello World THis is a text file hello.txt (END) >> cat shopping_list cucumber bread fish fingers >> sort shopping_list bread cucumber fish fingers >>date Thu Jul 9 00:21:17 IST 2020 >>date | cut -d " " -f1 Thu >>cat COPYING | less The GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most software and other practical works are designed >> cat COPYING | less | fmt -w 30 The GNU General Public License does not permit incorporating your program >>cat copybump.py #! /usr/bin/env python3 import datetime import os import re import stat import sys ... if __name__ == '__main__': do_walk() >> tac copybump.py do_walk() if __name__ == '__main__': ... import sys import stat import re import os import datetime #! /usr/bin/env python3 >> sed -f spelling.sed < report.txt > corrected.txt # correct the spellling mistake in report.txt and output the correct text in corrected.txt