how to take data in txt files such as mysql?

(my first language is no english) i want to take data in txt files line by line.

Example:(This is my txt files)

exampleline1
exampleline2
exa开发者_C百科mpleline3
exampleline4

(1)i want to select all lines and print. How to?

(2)For example i want to print line 4. How to?

$lines = file("file.txt");
foreach($lines as $line){
  echo $line."<br>";
}

to print line 4

echo $lines[3];

use (But be careful not to waste your memory):
file_get_contents
fgets
file

use function file(); which returns array (line by line)