PHP implementation code for reading and writing files

$fp = fopen("test.txt", "r");
?>

2.fclose (close file) grammar: fclose(filepointer) filepointer, the file pointer to be closed. The fclose function returns TRUE if successful and FALSE if failed. Example:

$fp = fopen("test.txt", "r");
fclose($fp);
?>

3.feof( Detects whether the end of file has been reached) grammar: feof(filepointer) filepointer, the file pointer to be detected, which must point to a file that was successfully opened but not closed. If the file pointer reaches the end of the file or an error occurs, the feof function returns TRUE. Example:

$fp = fopen("test.txt", "r");
while(! feof($fp))
{
echo fgets($fp). "< br />";
}
fclose($fp);
?>

4.fgets (read a line from the file pointer) grammar: fgets(filepointer) filepointer, the file pointer to be read. Reads a line from the file and returns a string if successful, or FALSE if failed. Example:

$fp = fopen("test.txt", "r");
if($fp)
{
for($i=1;! feof($fp); $i++)
{
echo "line ".$i." : ".fgets($fp). "";
}
}
else
{
echo "Failed to open file";
 }
fclose($fp);
?>

Assume the content of test.txt is: hello world hello cnblogs hello heihaozi hello everyone The page output results are: Line 1: hello world Line 2: hello cnblogs Line 3: hello heihaozi Line 4: hello everyone

5.fwrite (write file) grammar: fwrite(filepointer,string) filepointer, the file pointer to be written. string, the string to be written. Returns the number of characters written if successful, or FALSE if failed. Example:

$fp = fopen("test.txt", "w");//The file is cleared before writing
if($fp)
{
$count=0;
for($i=1;$i<=5;$i++)
{
$flag=fwrite($fp,"行".$i." : "."Hello World!rn");
if( !$flag)
{
echo "Failed to write file";
break;
}
$count+=$flag;
}
echo "A total of ".$count." characters written";
 }
else
{
echo "Failed to open file";
}
fclose($fp);
?>

The page output result is: Write a total of 100 characters

test.txt file will be written: Line 1: Hello World! Line 2: Hello World! Line 3: Hello World! Line 4: Hello World! Line 5: Hello World!