PHP, how to rewrite/change only 1 line in external txt file - php

First of all I know that there was topic about this, but I couldn't understand it so that I could use it in this case.
HTML: (Cannot be changed!)
<form action="index.php" method="get">
Select voting number:
<select name="candidate">
<option value=1 selected>1</option>
<option value=2>2</option>
<option value=3>3</option>
<option value=4>4</option>
<option value=5>5</option>
</select>
<br>
<input type="submit" value="Submit">
</form>
student.txt:
1|0
2|0
3|0
4|0
5|0
So the task is that, when user give number (1,2,3,4 or 5), that should change the line in txt file in that number line.
Example: user give value 2 ---> txt file should look like this:
1|0
2|1
3|0
4|0
5|0
next user give value 5:
1|0
2|1
3|0
4|0
5|1
and so on...
Also index.php should show total number of votes that txt file has including latest vote that user gave.

You could make use of external tools (sed etc in Linux) that you call from PHP, or finding the location in the file, moving file pointer and write the bytes that have changed. Depending on the layout of the file it can become more fiddly though if you all of a sudden want to add new records in the middle of the file.
The easiest way is basically, load data from file, update data and write data to file again. Sure you might write "more bytes than needed" for a small update, but it will be very easy to do.

<?php
$userInput = $_GET['candidate'];
$rows = explode(PHP_EOL, file_get_contents('votes.txt'));// Read file content and convert it into array
foreach($rows as $k => $v) {
$row = explode('|', $v);
if($userInput === $row[0]) {
$newTotal = (int)$row[1] + 1;
$rows[$k] = $row[0] . '|' . $newTotal;
$rows = implode(PHP_EOL, $rows);// Convert array to string again
file_put_contents('votes.txt', $rows);// Save changes
break;
}
}
I wouldn't have posted this answer, but I know sometimes schools give assignment and explain nothing. Don't just copy-paste this answer, try to understand the code. Please.

Related

How to parse an array into variables (PHP)?

For the life of me I cannot get this to work. I've looked at many articles on stackoverflow so if you could help that would be wonderful! I am working on a form submission for a client. They want to be able to select multiple values from a dropdown, which in turn I will pull from a database to get their query results.
<form id="test" action="results.php" method="POST">
<select id="role" name="role[]" multiple>
<option value="Student">Student</option>
<option value="Faculty">Faculty</option>
<option value="Alumni">Alumni</option>
</select>
<?php
$query="SELECT City FROM Cities";
$result = mysqli_query($link, $query);
echo '<select name="city" id="city" multiple>';
while($r = mysqli_fetch_assoc($result)){
echo '<option value="'.$r['City'].'">'.$r['City'].'</option>'; }
?>
</select>
<input type="submit"/>
</form>
//results.php
$results=array();
$results[] = $_POST['role'];
$results[]= $_POST['city'];
echo "<pre>";
print_r($results);
echo "</pre>";
**How do I obtain all the values from the array and parse it into separate variables so I can use the variables in a SQL statement? Here is my output: **
Array
(
[0] => Array
(
[0] => Faculty
[1] => Alumni
)
[2] => Adams
)
Thanks so much for any help! :) And if there is a better way to do this, let me know.
[EDIT] : This code is wild open to SQL Injection , Please don't use it.
One submit options i already have in the question and one i created
dummy submit options for city, run this code in the different file,
than select different different options, and click on submit button,
to check how our query is getting built
Please read the note first and make sure you read the comment in the code, as they are more important than the code
Note 1-> in short you want to run the query, according to the selected options by the user,
make sure you read the comment to understand the logic, comments are more important than the code it's self,
Note 2-> and more thing i did not realize, you may be storing your value in different different table, if that's the case, code will change little bit, but basic shell will remain the same
Note 3-> To achieve the out come which you want to achieve, you basically have to create your query according to the set options, and than use IN keyword and you are good go,
Note 4-> I added echo statement, so you can see stage by stage how our query is developing, i added the comment, if you want see just remove the comment, I did not add the comment in the last echo so you can see the ready to use query string
Note Again-> one submit options i already have, one i created by my self, so you can see what happening, and you it going to work out for you.
as you said in the comment you may have 12 field, in your form, if that's the case, use this code, because lets say if you have to change
some thing in the future, and you have to change at tweleve places,
you will make mistake like miss some thing, or use the wrong variable
or some thing else, with this code, you have to change it one place,
and it will get apply to 12 or 24 places, number of places does not
matter,
and one more thing, it will better if you wrap this php code inside the function, the reason is lets say you have form on some other page, and you need same functionality only thing you have to do than, just call the function, and in the future if you have change some thing, just change the function code
I am giving you example on your code why it is better to wrap this in a function, lets say your table name are different than the given selected name in your form or you decided to hole values in different different table, than you have to change the code, if you wrote this twelve times or each form, and than you have to change it, than you are in big trouble, but if you use this code as function for different different form, you just have to do some changes in function or in here, and will get applied everywhere, in short chances of you screwing up some thing is just not their, so hope fully this will help you
SideNote -- one more thing i want to say, the reason this solution look big, is because of note, form and comment, if you count the php code line, with out the last echo statement, it actually only 10 lines of php code, so dont get afraid, becuase it's look big
<form id="test" action="" method="POST">
<select id="role" name="role[]" multiple>
<option value="Student">Student</option>
<option value="Faculty">Faculty</option>
<option value="Alumni">Alumni</option>
</select>
<select id="city" name="city[]" multiple>
<option value="London">London</option>
<option value="Paris">Paris</option>
<option value="New York">New York</option>
</select>
<input type="submit">
</form>
<?php
//creating variable and saying all the post request is equal to this variable
$selected_options=$_POST;
foreach($selected_options as $key=>$option){
$countValue = count($option);
for($i=0; $i<$countValue; $i++){
/*
* start adding the value seperated by coma, remember again it going to
* be on extra coma so we have to remove it.
*/
$queryString_start_with_coma .= ",$option[$i]";
}
/*
* come out of loop, and now remove that extra coma
*/
$queryString_remove_extra_come= preg_replace("/,/", "", $queryString_start_with_coma, 1);
/*
* start building your query, use variable $key, just check the line below,
* you will understand where and why i am using variable $key.
*/
$query_string_with_and .= " AND $key IN($queryString_remove_extra_come)";
/*
* now unset the variable, this line is very important, so please also check
* your out come without this line,
* what i am simply doing is emptying the variable, if you dont
* do it, it will add the value in the existing value, which i dont want, what
* i want when the loop run for the second selected options, i want my variable
* to be empty, so i can create new string
* you will understand more if you remove this line and compare your two outcome
* Note: you dont have to unset if you dont want to, but you have empty the
* variable, you can also do by creating a empty string, do what ever you want
* to do, just make sure the variable is empty for the second loop
*/
unset($queryString_start);
}
$query_string_second_part_ready = preg_replace("/AND/", "", $query_string_with_and, 1);
//echo "$query_string_second_part_ready<br>";
$query_string= "SELECT * FROM table_name WHERE ".$query_string_second_part_ready;
//see how your query look like
echo $query_string;
It sounds like you want to be able to build a query based on the data submitted by the user. This may be a little more complex if you have multiple tables, but the basic idea is to use the input names with the fields, assemble the query from them, prepare the statement and bind the parameters.
Name the inputs the same as the database fields they match to
// Identify which database fields can be searched
// These names must match the names of the inputs
// Each name has a type which will be used later
$databaseFields = [ 'city' => 's', 'name' => 's', 'grade' => 'i' ];
$databaseFieldNames = array_keys($databaseFields);
// Set up the beginning of the query
$query = 'SELECT * FROM some_table WHERE ';
// Initialize an array to use to store fields to be searched
$where = [];
// Loop through all the post data
foreach ($_POST as $name => $value) {
// If the name is in the database fields list, add it to the query
if (in_array($name,$databaseFieldNames)) {
$where[] = $name;
}
}
// Add all the requested columns to the where
if (!empty($where)) {
$query .= ' '.$where[0].'=?';
array_pop($where);
foreach ($where as $name) {
if (is_array($_POST[$name])) {
// Use any to check for multiple possible values
$query .= ' AND '.$name.' = ANY (?)';
} else {
$query .= ' AND '.$name.'=?';
}
}
} else {
// Avoid an empty WHERE which will cause an error
$query .= ' TRUE';
}
$stmt = mysqli_prepare($query);
/* Bind parameters */
foreach ($where as $name) {
// $_POST should be validated here
if (is_array($_POST[$name])) {
// Arrays are imploded to work in an ANY
$value = "'".implode("','",addslashes($_POST[$name]))."'";
} else {
// Other values are used as sent
$value = $_POST[$name];
}
$type = $databaseFields[$name];
$stmt->bind_param($type,$value);
}
$stmt->execute();

Insert a .txt document into a select drop down?

I'm not sure if this is the best way of doing this or if it is even possible however what I'm trying to achieve is to echo out all these countries as a list in a select dropdown here is the list Country text document
So my question is how would I display these in a select dropdown or if I can't do this the way I'm trying to do it what would be the best way of doing it without manually adding each country to the form?
<select>
<option value="GB: United Kingdom">GB: United Kingdom</option>
<option value="etc">etc</option>
<option value="etc">etc</option>
<option value="etc">etc</option>
</select>
Remark: The .txt document mentioned in the question contains the list of world countries. It is a list with fixed content; it doesn't change during the execution of the program, it doesn't change between different executions of the program. It changes sometimes, not very often, when an entry is added or removed from the list. More often, the code or the name of existing items change.
This answer is tailored to the content of the file. It is not a recipe good for all situations.
The best way (given the content of the file you want to load) is to have the list of country names indexed by country code in the PHP code, in a separate file.
Something like this (file listCountries.php):
<?php
// ISO-3166 country codes
return array(
'AF' => 'Afghanistan',
'AX' => 'Åland Islands',
'AL' => 'Albania',
// ...
);
// This is the end of file; there is no need for a PHP close tag
When you need to use it, all you have to do is to write something like this:
$listCountries = include 'listCountries.php`;
Of course, you should put it somewhere in a directory of included files and take care of the path in the include line.
You can then iterate over $listCountries and generate the HTML code you need:
<select>
<?php
// Assuming the country with code $selectedCode have to be already selected in the list
foreach ($listCountries as $code => $name) {
$selected = ($code == $selectedCode) ? ' selected="selected"' : '';
echo('<option value="'.$code.'"'.$selected.'>'.htmlspecialchars($name)."</option>\n");
}
?>
</select>
You can generate the file using search and replace in your editor (if it knows search and replace with regular expressions) or you can write a little PHP script to generate the list for you:
$listCountries = array();
$fh = fopen('http://www.textfixer.com/resources/dropdowns/country-list-iso-codes.txt', 'r');
while (! feof($fh)) {
list($code, $name) = fgetcsv($fh, 0, ':');
$listCountries[$code] = $name;
}
fclose($fh);
echo("<?php\n");
echo('$listCountries = ');
var_export($listCountries);
echo(";\n");
echo("// That's all, folks!\n");
Run it using the PHP command line and it will dump the PHP code of the list to the output. You can either redirect its output to a file or change it to write the code into a file (the first option is easier).
You can read more about the ISO-3166 country codes on Wikipedia or you can get the up to date information directly from the authoritative source: the ISO.
A simple example which certainly needs more love:
<?php
$fh = fopen('list.text', 'r');
?>
<select>
<?php
while ($line = fgets($fh, 1024)) {
echo sprintf(' <option value="%1$s">%1$s</option>'."\n", trim($line));
}
?>
</select>
The output obviously is:
<select>
<option value="AF:Afghanistan">AF:Afghanistan</option>
<option value="AX:Åland Islands">AX:Åland Islands</option>
.....
</select>
The short answer is yes it is possible, but is it the best way? No, it isn't, there are many other better ways than plain text storage.
If you ask for advice I would tell you to do it from a DB table or from a JSON, even from a XML.
If you are going to change your mind and use one of these methods I recommend you to google it (You can find the structure that suits your application).
Any way as a guidance I have used these two recently:
DB Script format
JSON format
Right now in my case I'm using a JSON format.
To access and populate the select you can use javascript, more in particular JQuery would be handy, like this:
$.getJSON( "test.json", function( data ) {
var items = [];
$.each( data, function( key, val ) {
items.push( "<option value='" + key + "'>" + val + "</option>" );
});
});
For further information check the official manual.
If you prefer to populate your dropdown on the server you could do something like this:
$json = file_get_contents('your_json_url');
$countries = json_decode($json);
foreach ($countries as $option){
echo "<option value='" .$option[key]. "'>" .$option[$value]. "</option>";
}
If you want to do it from your databese the proccess is really similar as long as you also get an array.
If you still want to keep using your .txt format the #arkascha and #axiac answers are totally valid.
Hope this helped you ;)

Form search save in file & display result

What is the most elegant and efficient way of search a string against injected script file in PHP.
The flow:
i want make form search when user input strings & click search, data searched save on txt/php file with auto create new file based on month & year ex: -201601.php / txt
then data was saved on safety query with serial key on each string
then if data on -201601.php contents have more than 1000+ query, the data old was deleted automatic
then how showing 50 strings based on random strings on -201601.php
then in -201601.php there are no double string or same string
If you have a solution for my issue and want to post an answer, please add some explanation so that I can understand why/how you did it so that I won't come asking the same questions all over again. Thanks
Im search & create file that i want making it with my plot imagination. Here is what I have so far manually :
<center>
<form action="./cari.php?q=" method="GET">
<input type="text" name="q" value="" placeholder=" Cari .." style="cursor: pointer;width:69%"/>
<input type="submit" value="Search"/>
</form>
</center><?php
if(isset($_GET['q'])) {
$data = ''.$_GET['q']."<br>\n";
$ret = file_put_contents('rcnt.php', htmlspecialchars($data), FILE_APPEND | LOCK_EX);
if($ret === false) {
die('There was an error writing this file');
}
else {
//echo "$ret bytes written to file";
}
}
//else {die('no post data to process');}
?>
Im stuck searching with cant find related tutorial & hope find answer :(
Please your help, i want learn more with this, i use XAMPP 5.6
First step, the ?q= var the browser will create, you don`t need to set this on your form action.
<form method="get">
<input type="text" name="q" placeholder="search">
</form>
The PHP code will be:
<?php
if(!empty($_GET["q"]))
{
$file = fopen(date("Ym") . ".txt","a+");
fwrite($file, $_GET["q"] . "\r\n"); //\r\n jump the line
flose($file);
}
?>
If today is the 1st search of the 1st day of the month, the file will not exists, then, the PHP will create it, otherwise, will open and write on it.
Hope it could help you.
We could try this way:
<?php
$theFile = date("Ym") . ".txt";
$myFile = file($theFile);
for($i = 0; $i < 100; $i++){ //deleting the first 100 lines
unset($myFile[$i]);
}
//rewriting the file without the 100st first lines
file_put_contents($theFile, implode($myFile));
?>

PHP - Stop while loop after reading every single line from text file

I want the Code below to read individual line of text from dataFile.txt and show it in input field.
Problem is After reading first line from text document it shows all remaining lines of text from text file into input field. But on clicking submit it should show second line only then again on submitting it should show third line only, inside input field. please help.
<?php
$file = __DIR__."/dataFile.txt";
$f = fopen($file, "r");
$array1 = array();
<form action="datagGet.php" method="get">
<input type="text" value="
<?php while ( $line = fgets($f, 100) )
{
$nl = mb_strtolower($line);
echo $nl;
if(isset($_GET['done']))
{
$nl++;
}
else
{
break;
}
}
?>"
name="someText">
<input type="submit" name="done" >
</form>
You have several problems with you code. And the first comment above points to many of the. Key is the fact that the $_GET['done'] is set for the form submit and therefore you will echo all the lines of the output. It never breaks.
Also there is the fact that you are opening the file for reading each submit of the form. Although I don't see a simple way around this unless you store the file contents between requests.
One possible option is to use 'file()' to read the entire contents into an array. And then use sessions to store which line has been read. Then on each submit, look for the index of the array from the session read; advance it by one read the file again and return that line. Wow wasteful. But okay for simple site.
so use file to get the lines in an array.
output the first line into the value.
store the next index to be read in the $_SESSION variable like $_SESSION['next_line'] = 1
then upon further submissions. read it all back in. look up the 'next_line', and output that line.
so, for example
$array = file('your file name');
$output = $array[0];
if (isset($_SESSION['next_line']))
$_SESSION['next_line'] = intval($_SESSION['next_line']) + 1;
else
$_SESSION['next_line'] = 1;//prime the pump
echo the form with $output
then rinse and repeat. e.g. read, get output (next_line) with file, set $_session = next_line + 1; render output in form.
ps. some extra notes
* of course you'll need to start session on each request.
* you'll need to check if the $_SESSION['next_line'] is set. if not, set it to 1 (prime it)

PHP - get data from select box without the value

I'm having a bit of a confusing question but hopefully you'll get what I mean:
In my website I'm trying to implement a select box which is updated based on the value from a previous select box. For that I'm using a javascript that takes the values. For example an option from the select box looks like this:
<option value="22"> Apple </option>
I need the value in order to filter the select boxes but in my PHP script I need to get that 'Apple' text. Is there a way to do that?
Sorry for the noob question but web development is new for me.
Edit:
This is the java script I'm using for filtering the second select box:
$("#select1").change(function() {
if ($(this).data('options') == undefined) {
/*Taking an array of all options-2 and kind of embedding it on the select1*/
$(this).data('options', $('#select2 option').clone());
}
var id = $(this).val();
var options = $(this).data('options').filter('[value=' + id + ']');
$('#select2').html(options);
});
If I try to change this 'value' in the filter function to some other attribute it doesn't work for some reason. I don't know JavaScript at all.
Try this
var pName = document.getElementById('selectname');
var name = pName.options[pName.selectedIndex].text;
Send the name value to your php script by hidden form field or ajax request,
It will contain the text of the option
try this
function getSelectedText(elementId) {
var elt = document.getElementById(elementId);
if (elt.selectedIndex == -1)
return null;
return elt.options[elt.selectedIndex].text;
}
var text = getSelectedText('test');
or
this.options[this.selectedIndex].innerHTML
fruits_array.php
<?php
$fruits= array(
22 => 'apple' ,
23 => 'orange'
);
form_handler.php
if( isset($_POST['chosen_fruit']) && (int)$_POST['chosen_fruit'] > 0 ){
include 'fruits_array.php';
echo you chose ' . $fruits[$_POST['chosen_fruit'];
}
pick_your_fruit.php
<form action='form_handler.php' method= POST>
<select name='chosen_fruit'>
<?php
include 'fruits_array.php';
foreach($fruits as $key=$fruit)
echo '<option value=' . $key . '>' . $fruit .'</option>' . PHP_EOL ;
?>
<input type=submit />
</form>
Give this a try. Maintain an array of fruit in one place. Include it where you need it. If necessary that array could be from a database.
Use the array to
generate the form elements
generate the message
But, essentially, transferring the number of the key between the form and the form handler eases the thorny question of validating the incoming data.
DRY. Dont Repeat Yourself. Now if you have 99 fruit, and you add another, you only add it in one place.
(the main thing missing is the handling of a fruit number which does not exist, which probably means someone is tampering with you input form, leave that for another question, eh?)
Try like this
<form method="post" action="getvalue.php">
<select name="fruit">
<option value="">select the option</option>
<option value="1">Apple</option>
<option value="2">Banana</option>
<option value="3">Mango</option>
</select>
</form>
<?php
$option = array('1'=>'Apple','2'=>'Banana','3'=>'Mango');
echo $option[$_POST['fruit']];
?>
The Apple is not passed to the server, only your value, in this case 23. You can see that when you change your formular method to GET, it will look like script.php?some_select=23.
Two solutions to solve it:
The first one (the easy one) would be:
<option value="Apple" data-filterid="22"> Apple </option>
And in your js:
var options = $(this).data('options').filter('[data-filterid=' + id + ']');
So you get Apple in your php script instead of 22. You could then filter it in javascript by accessing data-filterid instead of value.
The second solution would be to store an associative dictionary which maps the value to the number, e.g.:
<?php
$mapped = array(22 => "Apple", 23=>"Orange");
$value = $mapped[$_GET['option_name']];

Categories