Question

What is the typical use of the 'sed' command?

1) Perform complex calculations
2) Perform FIFO based non-blocking I/O
3) Modify/print selective contents of a file

Answer 1

The 'sed' command is used to modify or print selective contents of a file, not for performing complex calculations or FIFO based non-blocking I/O. It's a text processing utility in Unix-like operating systems.

Step-by-step explanation:

The typical use of the 'sed' command is to modify/print selective contents of a file. This command stands for Stream Editor and is primarily used for text processing. It operates by performing actions like search, find and replace, insert, and delete within a text file. Various regex (regular expressions) can be used with 'sed' to select the specific lines where the modifications should take place. For example, replacing all occurrences of 'apple' with 'orange' in a file named 'fruits.txt' can be done with the following command:

sed 's/apple/orange/g' fruits.txt

Here, 's' represents the substitute command, 'g' denotes global replacement, and the expressions between the slashes define the search term and the replacement term.