Toolbox Aid

August 9th, 2024 9:27 AM Mr. Q Categories: Command

Command: cat

Used to concatenate and display the contents of one or more files.

---

Sample Command and Output:

$ cat file1.txt
This is the content of file1.txt.
It spans multiple lines.

Copy
001$ cat file1.txt
002This is the content of file1.txt.
003It spans multiple lines.

Description:

• cat file1.txt: Displays the contents of file1.txt on the terminal. It outputs the entire content of the file.

---

Sample Command and Output:

$ cat file1.txt file2.txt
This is the content of file1.txt.
It spans multiple lines.
This is the content of file2.txt.

Copy
001$ cat file1.txt file2.txt
002This is the content of file1.txt.
003It spans multiple lines.
004This is the content of file2.txt.

Description:

• cat file1.txt file2.txt: Concatenates and displays the contents of both file1.txt and file2.txt sequentially.

---

Sample Command and Output:

$ cat -n file1.txt
     1  This is the content of file1.txt.
     2  It spans multiple lines.

Copy
001$ cat -n file1.txt
002     1  This is the content of file1.txt.
003     2  It spans multiple lines.

Description:

• cat -n file1.txt: Displays the contents of file1.txt with line numbers prefixed. The -n option numbers the lines in the output.

---

Sample Command and Output:

$ cat > newfile.txt
This is the content being written to newfile.txt.
Ctrl+D
$ cat newfile.txt
This is the content being written to newfile.txt.

Copy
001$ cat > newfile.txt
002This is the content being written to newfile.txt.
003Ctrl+D
004$ cat newfile.txt
005This is the content being written to newfile.txt.

Description:

• cat > newfile.txt: Redirects input from the terminal to newfile.txt. Type the content and press Ctrl+D to save and exit. The cat command then displays the content of newfile.txt.

---

Sample Command and Output:

$ cat file1.txt | grep "search_term"
This line contains the search_term.

Copy
001$ cat file1.txt | grep "search_term"
002This line contains the search_term.

Description:

• cat file1.txt | grep "search_term": Uses cat to display the contents of file1.txt and pipes it to grep, which searches for lines containing search_term.

---