Intermediate shell commands

In the previous section, we used some basic commands in order to get used to Terminal. In this section, we will get familiar with more advanced commands, as follows:

• echo: The echo command allows you to display content that can be added to either a new or an existing file or to replace the content.
• If you want to add content to an existing file, you can use echo "content to be appended" >>file1.txt. Or, you can use echo "this content will replace" > file1.txt to replace the content of a file.

You can see the echo command in use here:

Figure 2.6 – echo command

• cat: The cat command is normally used to read the content of a file, as illustrated here:

Figure 2.7 – cat command

You can use the cat command and append the output to a new file using >>. This is the same for any output—for example, you can use ls –la...