Lecture 2 – Feb 5th, 2020

Setup

Log on to clyde: ssh user@clyde.cs.oberlin.edu.

Task

Create a directory named books using mkdir.
cd into the directory.
wget to download a copy of Bram Stoker’s Dracula from https://www.gutenberg.org/cache/epub/345/pg345.txt. (Try running either $ wget --help or $ man wget to see how to use wget to download files.
Using mv rename the file from pg345.txt to Stoker, Bram - Dracula.txt. Since this file name has spaces, you’ll need to specify it as 'Stoker, Bram - Dracula.txt' or Stoker,\ Bram\ -\ Dracula.txt.
The grep command is used for searching for text files for a “pattern” and printing out each line that matches the pattern. For example, $ grep vampire 'Stoker, Bram - Dracula.txt' prints out each line containing the word vampire (in lower case).
Read grep’s man page to figure out how to perform a case-insensitive search and run the command to print out all lines matching vampire, case insensitively. Hint: typing /case (and then hit enter) while viewing a man page will search for case in the manual. While searching, you can press n/N to go to the next/previous instance.
Use grep to print out a count of the lines matching vampire case insensitively. (Search the man page again.)
You’re probably tired of typing the same command and file name over and over, try using the up/down arrows to move back and forth through the history of your commands and then editing the commands to make new ones. You can also use tab-completion to get Bash to fill in the rest of the name for you: start typing the file name and then hit tab.
Open the man page for grep one final time and figure out how to get grep to print the line numbers (and the lines themselves) that match Transylvania and then do that.
Use wget again to download James Joyce’s Dubliners from https://www.gutenberg.org/files/2814/2814-0.txt. Rename it Joyce, James - Dubliners.txt.
Find and use the command to print out a count of every word in both books. Hint, the -a (or --and) option to apropos lets you search for commands that involve all of the key words so $ apropos -a apple sauce will match commands whose descriptions contain both the words apple and sauce. So use appropos -a with appropriate keywords to find a command that produces a word count.
Run that command on all .txt files in the current directory using
```
$ cmd *.txt
```
where cmd is the command you found with apropos.
This is called a glob and we’ll talk about it next time.
Read the man page for the command you found in step 9 and find and use the option to print only the word counts.
Go to the parent directory (cd ..) and delete the books directory. Note that neither $ rm books nor $ rmdir books will work.
```
steve@clyde:~$ rm books
rm: cannot remove 'books': Is a directory
steve@clyde:~$ rmdir books
rmdir: failed to remove 'books': Directory not empty
```
Read the man page for rm to figure out how to recursively delete directories.