WorkShop 4

ITC382 Client Server Applications
Tutorial 4

MANIPULATING FILES and DIRECTORIES


Files

1. Testing files, lets test for some existence and status of a file called text1.txt


<?php



// Checking its existence

if (file_exists("text1.txt")) {

echo "The file text1.txt exists!";

}



// checking the status of files

if (is_readable("text1.txt")) {

echo "The file text1.txt is readable";

}



if (is_writeable("text1.txt")) {

echo "The file text1.txt is writeable";

}



if (is_executable("text1.txt")) {

echo "The file text1.txt is exectuable";

}

?>




You probably only see "The file text1.txt exists". If you only see this, you will need to chmod the read,write and execute settings on that file.

2. Reading data from files


<?php



$filename = "text1.txt";

$fp = fopen($filename, "r") or die ("Could not open $filename");

while (!feof($fp)) { // While not end of file

$data = fread($fp, 16); // Reading the file in chunkcs of 16 bytes

echo "$data <br>";

}

?>





There are multiple ways you can read from a file includes
Fgets() : Reading line by line
Fgetc() : Reading a character



3. Writing to a file


<?php



$filename = "text1.txt";

echo "Begin writing to file $filename <br>";

$fp = fopen($filename, "w") or die ("Could not open $filename"); // OPen for writing

fwrite ($fp, "I'm making changes \n");

fclose($fp);

?>




If you have trouble writing to the file, it could be a permission setting. Try chmod 777 . This will give all permissions to the file only. Chmod 777 to the directory give all permissions to the directory and not advisable.

4. Appending to a file


<?php



$filename = "text1.txt";

echo "Appending to a file $filename <br>";

$fp = fopen($filename, "a") or die ("Could not open $filename"); // OPen for writing

fputs ($fp, "\n Another thing I want to add  \n");

fclose($fp);

?>




The file text1.txt will have a new line called Another thing I want to add.


Directories

1. Creating a new directory


<?php



mkdir ("testdir", 0755);

?>




If you failed to create a directory, again it usually means you have incorrect permissions settings.


2. Directory listing


<?php



$dirname = ".";

$dn = opendir($dirname) or die ("Could not open directory");



while (!(($file = readdir($dn)) === false ) ) {

if (is_dir("$dirname/$file")) {

echo "(D) "; // To signify a folder

}

echo "$file <br>";

}

closedir ($dn);

?>