PHP - Searching words in a .txt file - php

Question

I have just learnt some basic skill for html and php and I hope someone could help me .
I had created a html file(a.html) with a form which allow students to input their name, student id, class, and class number .
Then, I created a php file(a.php) to saved the information from a.html into the info.txt file in the following format:
name1,id1,classA,1
name2,id2,classB,24
name3,id3,classA,15
and so on (The above part have been completed with no problem) .
After that I have created another html file(b.html), which require user to enter their name and id in the form.
For example, if the user input name2 and id2 in the form, then the php file(b.php) will print the result:
Class: classB
Class Number: 24
I have no idea on how to match both name and id at the same time in the txt file and return the result in b.php

Answer 1

example data:
name1,id1,classA,1
name2,id2,classB,24
name3,id3,classA,15
<?php
$name2 = $_POST['name2'];
$id2 = $_POST['id2'];
$data = file_get_contents('info.txt');
if($name2!='')
$konum = strpos($data, $name2);
elseif($id2!='')
$konum = strpos($data, $id2);
if($konum!==false){
$end = strpos($data, "\n", $konum);
$start = strrpos($data, "\n", (0-$end));
$row_string = substr($data, $start, ($end - $start));
$row = explode(",",$row_string);
echo 'Class : '.$row[2].'<br />';
echo 'Number : '.$row[3].'<br />';
}
?>

Answer 2

Iterate through lines until you find your match. Example:
<?php
$csv=<<<CSV
John,1,A
Jane,2,B
Joe,3,C
CSV;
$data = array_map('str_getcsv', explode("\n", $csv));
$get_name = function($number, $letter) use ($data) {
foreach($data as $row)
if($row[1] == $number && $row[2] == $letter)
return $row[0];
};
echo $get_name('3', 'C');
Output:
Joe

Answer 3

You could use some simple regex. For example:
<?php
$search_name = (isset($_POST['name'])) ? $_POST['name'] : exit('Name input required.');
$search_id = (isset($_POST['id'])) ? $_POST['id'] : exit('ID input required.');
// First we load the data of info.txt
$data = file_get_contents('info.txt');
// Then we create a array of lines
$lines = preg_split('#\\n#', $data);
// Now we can loop the lines
foreach($lines as $line){
// Now we split the line into parts using the , seperator
$line_parts = preg_split('#\,#', $line);
// $line_parts[0] contains the name, $line_parts[1] contains the id
if($line_parts[0] == $search_name && $line_parts[1] == $search_id){
echo 'Class: '.$line_parts[2].'<br>';
echo 'Class Number: '.$line_parts[3];
// No need to execute the script any further.
break;
}
}

Answer 4

You can run this. I think it is what you need. Also if you use post you can change get to post.
<?php
$name = $_GET['name'];
$id = $_GET['id'];
$students = fopen('info.txt', 'r');
echo "<pre>";
// read each line of the file one by one
while( $student = fgets($students) ) {
// split the file and create an array using the ',' delimiter
$student_attrs = explode(',',$student);
// first element of the array is the user name and second the id
if($student_attrs[0]==$name && $student_attrs[1]==$id){
$result = $student_attrs;
// stop the loop when it is found
break;
}
}
fclose($students);
echo "Class: ".$result[2]."\n";
echo "Class Number: ".$result[3]."\n";
echo "</pre>";

Answer 5

strpos can help you find a match in your file. This script assumes you used line feed characters to separate the lines in your text file, and that each name/id pairing is unique in the file.
if ($_POST) {
$str = $_POST["name"] . "," . $_POST["id"];
$file = file_get_contents("info.txt");
$data = explode("\n", $file);
$result = array();
$length = count($data);
$i = 0;
do {
$match = strpos($data[$i], $str, 0);
if ($match === 0) {
$result = explode(",", $data[$i]);
}
} while (!$result && (++$i < $length));
if ($result) {
print "Class: " . $result[2] . "<br />" . "Class Number: " . $result[3];
} else {
print "Not found";
}
}