Shell Data Processing - (WC|Word Count) command (Line count)

With Standard Input from a pipeline

• with the file hello.txt. You can create it with the below command in bash that uses echo gnu.

/bin/echo -e 'Hello\nWorld' > hello.txt
# -e takes the sequence character \n has an end of line

Hello
World

• How many line, word and characters do we have by using a pipeline in order to create the input stream with cat

cat hello.txt | wc # read from the input stream created by cat

2       2      12

With Manual Standard Input (Copy / Paste )

wc -

• Manually:
  • Type your text
  • or copy/paste:
    • in bash, right click to paste,
    • in dos, ctrl+v
• Then send and end of file character
  • in bash: Ctrl+D
  • in dos: Ctrl+Z (^Z) on Windows

Example when copy/pasting

The wc command is a filter that prints on one line sequentially the number of:

newlines (lines),
words,
and characters

5      20     120 -

With a file as argument

When using a file name as argument

wc hello.txt # transform hello.txt as an input stream and read 

2  2 12 hello.txt

With a glob pattern that select files as argument

with a a glob pattern that select all files that begins with hello

wc hello*

2  2 12 hello.txt
 1  2 12 helloIn.txt
 1  2 12 helloOut.txt
 4  6 36 total