Bash cat
- Concatenate and Display Files
Using the cat
Command
The cat
command is used to show the content of files in the terminal.
You can also use it to combine multiple files into one.
Basic Usage
To display the content of a file, use cat filename
:
Example
cat my_file.txt
Understanding Shells
A shell is a text-based interface that lets you talk to your computer.
There are different types of shells. Bash (Bourne Again SHell)
is popular because it's powerful and easy to use.
Options
The cat
command has options to change how it shows text:
-n
- Add numbers to each line-b
- Add numbers only to lines with text-s
- Remove extra empty lines-v
- Show non-printing characters (except for tabs and end of line)
-n
Option: Number All Lines
The -n
option adds numbers to each line of the output.
Example: Number All Lines
cat -n my_file.txt
1 Understanding Shells
2 A shell is a text-based interface that lets you talk to your computer.
3
4 There are different types of shells. Bash (Bourne Again SHell)
5 is popular because it's powerful and easy to use.
-b
Option: Number Non-Blank Lines
The -b
option adds numbers only to lines with text, ignoring blank lines.
Example: Number Non-Blank Lines
cat -b my_file.txt
1 Understanding Shells
2 A shell is a text-based interface that lets you talk to your computer.
3 There are different types of shells. Bash (Bourne Again SHell)
4 is popular because it's powerful and easy to use.
-s
Option: Suppress Repeated Empty Lines
The -s
option removes extra empty lines from the output, leaving only a single blank line where multiple ones existed.
Example: Suppress Repeated Empty Lines
cat -s my_file.txt
Understanding Shells
A shell is a text-based interface that lets you talk to your computer.
There are different types of shells. Bash (Bourne Again SHell)
is popular because it's powerful and easy to use.
-v
Option: Show Non-Printing Characters
The -v
option makes non-printing characters visible, except for tabs and end-of-line characters.
This is useful for debugging files with hidden characters.
Example: Show Non-Printing Characters
cat -v my_file.txt
Concatenate Two Files
The cat
command can be used to concatenate multiple files into one.
This is useful for combining files or appending content to an existing file.
Example: Concatenate Two Files
cat file1.txt file2.txt > combined.txt
This command takes the contents of file1.txt
and file2.txt
and writes them into combined.txt
.
Using cat
with Piping
The cat
command is often used with piping to send the content of files to other commands.
This is useful for processing text data.
Example
cat my_file.txt | grep "shells"
Understanding Shells
There are different types of shells. Bash (Bourne Again SHell)