In Linux/Unix, you can use the “head” command to display the first N lines of a file. By default, the head command displays the first 10 lines of a file. To display a different number of lines, use the “-n” option followed by the number of lines you want to see.
For example, to display the first 20 lines of a file named “file.txt”, use the following command:
head -n 20 file.txt
You can also use the “less” command to view the contents of a file one page at a time, and navigate through the file using the up and down arrow keys. To display the first 20 lines of a file using the “less” command, use the following command:
$ less -N file.txt