Finding the Number of Lines in a File Using PHP

To find the number of lines in a file using PHP, there are some approaches you can use. Here’s a breakdown of each method:

Approach 1: Load Entire File into Memory
You can load the entire file into memory and use the count() function to count the number of lines.

Pros: Simple and easy.
Cons: For large files, this method can lead to memory overflow.
Example:

$filePath = "test.txt"; 
$lines = count(file($filePath)); 
echo $lines;

//output 3

Approach 2: Load One Line at a Time
This method loads one line at a time using fopen() to open the file and fgets() to read each line. It avoids memory overload.

Pros: Efficient for larger files.
Cons: Can still be inefficient for very large files with minimal lines.
Example:

$filePath = "test.txt"; 
$linecount = 0; 
$handleFile = fopen($filePath, "r"); 
while(!feof($handleFile)) { 
  $line = fgets($handleFile); 
  $linecount++; 
}
fclose($handleFile); 
echo $linecount;

//output 3

Approach 3: Load Specific Data Sizes (4096 Bytes)
In this approach, only a specific amount of data (e.g., 4096 bytes) is loaded at a time. This prevents memory overflow and counts lines more efficiently using PHP_EOL to detect line breaks.

Pros: Space-efficient.
Cons: Requires iterating over data twice, so it’s slower in terms of time.
Example:

$filePath = "test.txt"; 
$linecount = 0; 
$handleFile = fopen($filePath, "r"); 
while(!feof($handleFile)) { 
  $line = fgets($handleFile, 4096); 
  $linecount += substr_count($line, PHP_EOL); 
}
fclose($handleFile); 
echo $linecount;

Keep Learning 🙂