In this project, you’ll use the commands you just learned to redirect files in Athletica, a sporting events directory.
Redirection is a feature in Linux such that when executing a command, you can change the stadard input/output devices. The basic workflow of any Linux command is that it takes an input and give an output. It is similar but different from pipes, as it allows reading/writting from files instead of only commands. Redirecting can be done by using the operators > >>.
- The stadard input (stdin) device is the keyboard.
- The standard output (stdout) device is the screen.
- Print the working directory
- List all the files and directories in long format, including hidden files.
- Use
catto view the contents of basketball.txt - Use
catto view the content of hockey.txy - Redirect the stadard output of basketball.txt into hockey.txt Then view the contents of hockey.txt
- View the contents of lacrosses.txt
- Append the contennts of lacrosse.txt to the contents of tennis.txt Then view the contents of tennis.txt
- Redirect the contents of gymnastics.txt as stadard input for the
catcommand. - Pipe the standard output of
cat laccrosse.txtto the wordcount command. - Use
catto view the contents of equipment.txt. - Sort the contents of equipment.txt in alphabetical order.
- Use the
uniqcommand to filter out adjacent, duplicate lines in equipment.txt - Use
grepcommand to search roseter.txt for players from Japan. - Use the
grepcommand to search for the string 'player' in the current directories(.), and output filenames and lines for matched results. - Use
catto view the contents of games.txt. Then, usesedto replaces all instances of words 'loss' with 'win' in games.txt
1
$ pwd
/home/ccuser/workspace/athletica
2
$ ls -la
total 56
drwxr-xr-x 2 ccuser ccuser 259 Aug 24 01:48 .
drwxrwxr-x 1 ccuser ccuser 23 Aug 24 01:48 ..
-rw-r--r-- 1 ccuser ccuser 102 Aug 24 01:48 badminton.txt
-rw-r--r-- 1 ccuser ccuser 97 Aug 24 01:48 basketball.txt
-rw-r--r-- 1 ccuser ccuser 161 Aug 24 01:48 cricket.txt
-rw-r--r-- 1 ccuser ccuser 6148 Mar 5 2016 .DS_Store
-rw-r--r-- 1 ccuser ccuser 304 Aug 24 01:48 equipment.txt
-rw-r--r-- 1 ccuser ccuser 117 Aug 24 01:48 football.txt
-rw-r--r-- 1 ccuser ccuser 393 Aug 24 01:48 games.txt
-rw-r--r-- 1 ccuser ccuser 130 Aug 24 01:48 gymnastics.txt
-rw-r--r-- 1 ccuser ccuser 97 Aug 24 01:50 hockey.txt
-rw-r--r-- 1 ccuser ccuser 159 Aug 24 01:48 lacrosse.txt
-rw-r--r-- 1 ccuser ccuser 605 Aug 24 01:48 roster.txt
-rw-r--r-- 1 ccuser ccuser 69 Aug 24 01:48 swimming.txt
-rw-r--r-- 1 ccuser ccuser 319 Aug 24 01:52 tennis.txt
$
3
$ cat basketball.txt
Basketball is a sport played by two teams of five players on a rectangular court. Src: Wikipedia
4
$ cat hockey.txt
Basketball is a sport played by two teams of five players on a rectangular court. Src: Wikipedia
5
$ cat basketball.txt > hockey.txt
$ cat hockey.txt
Basketball is a sport played by two teams of five players on a rectangular court. Src: Wikipedia
6
cat lacrosse.txt
Lacrosse is a contact team sport played between two teams using a small rubber ball and a long-handled stick called a crosse or lacrosse stick. Src: Wikipedia
7
$ cat lacrosse.txt >> tennis.txt
$ cat tennis.txt
Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Src: Wikipedia
Lacrosse is a contact team sport played between two teams using a small rubber ball and a long-handled stick called a crosse or lacrosse stick. Src: Wikipedia
Lacrosse is a contact team sport played between two teams using a small rubber ball and a long-handled stick called a crosse or lacrosse stick. Src: Wikipedia
8
$ cat < gymnastics.txt
Gymnastics is a sport involving the performance of exercises requiring strength, flexibility, balance and control. Src: Wikipedia
9
$ cat lacrosse.txt | wc
1 27 159
10
$ cat equipment.txt
baseball
shuttlecock
shuttlecock
helmet
football
cleats
cleats
cleats
tennis ball
baseball bat
lacrosse stick
hockey stick
hockey stick
hockey stick
tennis racket
cricket bat
cricket bat
cricket bat
goggles
googles
swimming cap
lacrosse ball
hockey puck
sneakers
sneakers
skates
skates
skates
shinguards
$
11
$ sort equipment.txt
baseball
baseball bat
cleats
cleats
cleats
cricket bat
cricket bat
cricket bat
football
goggles
googles
helmet
hockey puck
hockey stick
hockey stick
hockey stick
lacrosse ball
lacrosse stick
shinguards
shuttlecock
shuttlecock
skates
skates
skates
sneakers
sneakers
swimming cap
tennis ball
tennis racket
12
$ uniq equipment.txt
baseball
shuttlecock
helmet
football
cleats
tennis ball
baseball bat
lacrosse stick
hockey stick
tennis racket
cricket bat
goggles
googles
swimming cap
lacrosse ball
hockey puck
sneakers
skates
13
$ grep Japan roster.txt
Yuki Hayashi, Swimming: Japan
Misako Sato, Gymnastics: Japan
Takumi Fujiwara, Basketball: Japan
Toshi Ogawa, Badminton: Japan
14
$ grep -R player
basketball.txt:Basketball is a sport played by two teams of five players on a rectangular court. Src: Wikipedia
cricket.txt:Cricket is a bat-and-ball game played between two teams of 11 players each on a field at the centre of which is a rectangular 22-yard-long pitch. Src: Wikipedia
hockey.txt:Basketball is a sport played by two teams of five players on a rectangular court. Src: Wikipedia
tennis.txt:Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Src: Wikipedia
15
$ sed 's/loss/win/g' games.txt
Australia vs United Kingdom
Australia: win
United States vs South Africa
United States: win
Mexico vs Colombia
Colombia: win
Brazil vs Argentina
Brazil: win
Kenya vs Ghana
Kenya: win
Jordan vs Morocco
Morocco: win
Malaysia vs Singapore
Singapore: win
India vs China
India: win
Pakistan vs Uzbekistan
Uzbekistan: win
Greece vs Turkey
Greece: win
France vs Spain
France: win$
Redirecting Output
The > symbol is used to redirect output by taking the output from the command on the left and passing as input to the file on the right.
cho "Hello" > hello.txt
cat Display
The shell command cat displays the contents of one or more files to the terminal.
$ cat poem.txt
$ cat poem.txt kitties.txt
Append Redirect shell command
The >> shell command is used to redirect the standard output of the command on the left and append (add) it to the end of the file on the right.
# This command will append "Hello World!" to greetings.txt
echo "Hello World!" >> greetings.txt
Pipe shell command
The | command is called a pipe. It is used to pipe, or transfer, the standard output from the command on its left into the standard input of the command on its right.
# First, echo "Hello World" will send Hello World to the standard output.
# Next, pipe | will transfer the standard output to the next command's standard input.
# Finally, wc -w will count the number of words from its standard input, which is 2.
echo "Hello World" | wc -w
grep Search
The shell command grep is used to search files for lines that match a pattern and returns the results. Various options can be specified along with the grep command to specify the search.
In the provided example, the lines in the file names.txt which contain “sonny” will be returned.
grep 'sonny' names.txt
Case insensitive search
The shell grep command searches files for a particular pattern. The grep command with the -i option can be used to search files for lines that match a pattern, case insensitive, and returns the results.
grep -R shell command
The shell command grep has a -R option (grep -R) that searches all files in a directory, including its subdirectories, and outputs filenames and lines containing matched results.
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