process_text_data.md

4. Process text data

Please go to the directory exercise_4.

4.1. comparing two files

There are two different versions of a text, foo_long.txt, and foo_short.txt. To find out, how they differ, Unix provides the command

diff <filename1> <filename2>

Of course, you can look at the text first using more or a text editor. The 11th character of the solution is the first character of the third last word in the output of diff.

4.2. Sorting a text file

Unix has a small program to sort text files alphabetically. It is called by

more <filename> | sort

The symbol '|' is called a pipe and is often used to connect Unix programs to each other. The 12th character of the solution is the first character of the last word of the first line from the alphabetically sorted file 10000_lines.txt.

Hint

To store the sorted lines in a new file, you can add an output file, like

more <filename> | sort > result.txt

4.3. Finding words in a text file

To look for specific words in a text file, the

grep <word> <filename>

command should be used. It produces all lines from the given file that contain the given word. The grep command is very powerful and can handle fuzzy search patterns called Regular Expressions (not covered here). The 13th character of the solution is the first character of the second word in a line containing 'fool'.

Hint:

You can search through many files at once by including a '*' in the filename.