php cannot write new line, file gets overwirtten - php

I have read a lot of questions, none of which worked. I have a txt file. The first line contains headers separated by a tab "\n". Now when i post to this file I want it to take the values and separate them by a tab and then write them on a new line of the txt file. But when I run it, it just overwrites the first line.
<?php
$post = $_POST;
$myFile = 'test.txt';
$fh = fopen($myFile, 'w');
$columns = "";
foreach ($post as $key => $value){
$columns .= $value . "\t";
}
fwrite($fh, $columns . PHP_EOL);
fclose($fh);
?>

You're looking for a instead w:
$fh = fopen($myFile, 'a');
From the docs:
'w' Open for writing only; place the file pointer at the beginning of
the file and truncate the file to zero length. If the file does not
exist, attempt to create it.
'a' Open for writing only; place the file pointer at the end of the
file. If the file does not exist, attempt to create it.

w is used for writing which means anything before gets overwritten.
Change the following line:
$fh = fopen($myFile, 'w'); //w = write
To
$fh = fopen($myFile, 'a'); //a = append
It should fix the issue for you.

Try $fh = fopen($myFile, 'a'); if you don't want to overwrite content.
Using w overwrites, while a or a+ appends.
For more information on the fwrite() function, you can consult the PHP manual.
http://php.net/manual/en/function.fwrite.php
Also consult the PHP manual on fopen() http://php.net/manual/en/function.fopen.php
'a' Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
'a+' Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it.

Related

php records erasing txt

A registration form write the data to a txt file using this code:
<?
if( isset( $_GET['list'] ) AND $_GET['list'] != '' ) {
$listId = $_GET['list'];
}
$email = $_POST['widget-subscribe-form-email'];
$fname = isset( $_POST['widget-subscribe-form-fname'] ) ? $_POST['widget-subscribe-form-fname'] : '';
$lname = isset( $_POST['widget-subscribe-form-lname'] ) ? $_POST['widget-subscribe-form-lname'] : '';
$fp = fopen("newsletter_subscriptions.txt","w+");
fputs($fp, "email : ");
fputs($fp, $_POST['widget-subscribe-form-email']);
fputs($fp, "\nPrénom : ");
fputs($fp, $_POST['widget-subscribe-form-fname']);
fputs($fp, "\nNom : ");
fputs($fp, $_POST['widget-subscribe-form-lname']);
fclose($fp);
?>
My problem is that each new record erase the previous one. I want to keep all records in the txt file.
How to do it ?
File open modes:
w+ Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
a+ Open for reading and writing; place the file pointer at the end of the file.
You are opening the file in the wrong mode. From the manual:
'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
You want to append to the file, you should use:
'a+' Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it. In this mode, fseek() only affects the reading position, writes are always appended.
Change the fopen line to:
$fp = fopen("newsletter_subscriptions.txt","a+");

how can i add email in one by one using read/write in php

how can i add email in one by one using read/write in php
Am getting the following output and create one folder called "update" update folder contain user entered one email is stored and user enter another email id already existing email id replaced to new email id why?
I need one by one email id called
apap#gmail.com
asadsd#gmail.com
here are my code please review
<form action="demo.php" method="post">
<input type="text" name="textEmail">
<input type="submit" value="send">
</form>
Demo.php file are
<?php
// Open the text file
$f = fopen("update.txt", "w");
// Write text
$text = strtr(" ",' ', $_POST['textEmail']);
fwrite($f,$text);
//fwrite($f,$text);
// Close the text file
fclose($f);
// Open file for reading, and read the line
$f = fopen("update.txt", "r");
// Read text
echo fgets($f);
fclose($f);
?>
Open the file in append mode instead of write mode
replace "w" with "a"
$f = fopen("update.txt", "a");
From: http://php.net/manual/en/function.fopen.php
'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'a' Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it...
Open your file as append mode so that you not need to open the file twice, for writing in the file, for you one email per line you need to use the \n after each email. For reading use the while loop to read end of the file and use fgets to make sure it reads the whole line at a time.
$myfile = fopen("update.txt", "a+");
$txt = $_POST['textEmail']."\n";
fwrite($myfile, $txt);
while(!feof($myfile)) {
echo fgets($myfile) . "<br/>";
}
fclose($myfile);
Documentation: php_file_create and php_file_open
I am unsure on what you are trying to achieve but I will clarify the difference between file write and file append.
Writing to a file when opened in 'w' mode writes from the current file pointer position which when open in 'w' mode is the very beginning of the file, to change this position in this mode use the fseek() method.
Writing to a file when opened in 'a' mode (append mode) will set the file pointer to the last location in the file and in php specifically will always when fwrite() is called will write to the end of the file.
Append File Example
Contents of update.txt before write:
sometext
sometext2
Code that writes to file
$f = fopen('update.txt', 'w');
//Description of 'a' mode from php manual
//Open for writing only; place the file pointer at the end of the file.
//If the file does not exist, attempt to create it. In this mode,
//fseek() has no effect, writes are always appended.
fwrite($f, "somevalue" . "\n");
fclose($f);
Results In an update.txt with contents:
sometext
sometext2
somevalue
Php doc on functions used in this example:
fopen()
fwrite()
<?php
if ($_POST['textEmail'] != '') {
$text = str_replace(" ", ' ', $_POST['textEmail']);
$pattern = '/([a-zA-Z0-9._%+-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6})/';
preg_match_all($pattern,file_get_contents("update.txt"), $matches);
$emails = $matches[0]; // get Array of all email in file
if (!in_array($text, $emails)) { // echck for existing email
file_put_contents("update.txt", PHP_EOL.$_POST['textEmail'], FILE_APPEND);
}else{
echo 'Email address alerady exist';
}
echo $f = file_get_contents("update.txt");
}
?>
Would you please try this for demo.php ?

Append at the beginning of the file in PHP [duplicate]

This question already has answers here:
Need to write at beginning of file with PHP
(10 answers)
Closed 9 years ago.
Hi I want to append a row at the beginning of the file using php.
Lets say for example the file is containing the following contnet:
Hello Stack Overflow, you are really helping me a lot.
And now i Want to add a row on top of the repvious one like this:
www.stackoverflow.com
Hello Stack Overflow, you are really helping me a lot.
This is the code that I am having at the moment in a script.
$fp = fopen($file, 'a+') or die("can't open file");
$theOldData = fread($fp, filesize($file));
fclose($fp);
$fp = fopen($file, 'w+') or die("can't open file");
$toBeWriteToFile = $insertNewRow.$theOldData;
fwrite($fp, $toBeWriteToFile);
fclose($fp);
I want some optimal solution for it, as I am using it in a php script. Here are some solutions i found on here:
Need to write at beginning of file with PHP
which says the following to append at the beginning:
<?php
$file_data = "Stuff you want to add\n";
$file_data .= file_get_contents('database.txt');
file_put_contents('database.txt', $file_data);
?>
And other one here:
Using php, how to insert text without overwriting to the beginning of a text file
says the following:
$old_content = file_get_contents($file);
fwrite($file, $new_content."\n".$old_content);
So my final question is, which is the best method to use (I mean optimal) among all the above methods. Is there any better possibly than above?
Looking for your thoughts on this!!!.
function file_prepend ($string, $filename) {
$fileContent = file_get_contents ($filename);
file_put_contents ($filename, $string . "\n" . $fileContent);
}
usage :
file_prepend("couldn't connect to the database", 'database.logs');
My personal preference when writing to a file is to use file_put_contents
From the manual:
This function is identical to calling fopen(), fwrite() and fclose()
successively to write data to a file.
Because the function automatically handles those three functions for me I do not have to remember to close the resource after I'm done with it.
There is no really efficient way to write before the first line in a file. Both solutions mentioned in your questions create a new file from copying everything from the old one then write new data (and there is no much difference between the two methods).
If you are really after efficiency, ie avoiding the whole copy of the existing file, and you need to have the last inserted line being the first in the file, it all depends how you plan on using the file after it is created.
three files
Per you comment, you could create three files header, content and footer and output each of them in sequence ; that would avoid the copy even if header is created after content.
work reverse in one file
This method puts the file in memory (array).
Since you know you create the content before the header, always write lines in reverse order, footer, content, then header:
function write_reverse($lines, $file) { // $lines is an array
for($i=count($lines)-1 ; $i>=0 ; $i--) fwrite($file, $lines[$i]);
}
then you call write_reverse() first with footer, then content and finally header. Each time you want to add something at the beginning of the file, just write at the end...
Then to read the file for output
$lines = array();
while (($line = fgets($file)) !== false) $lines[] = $line;
// then print from last one
for ($i=count($lines)-1 ; $i>=0 ; $i--) echo $lines[$i];
Then there is another consideration: could you avoid using files at all - eg via PHP APC
You mean prepending. I suggest you read the line and replace it with next line without losing data.
<?php
$dataToBeAdded = "www.stackoverflow.com";
$file = "database.txt";
$handle = fopen($file, "r+");
$final_length = filesize($file) + strlen($dataToBeAdded );
$existingData = fread($handle, strlen($dataToBeAdded ));
rewind($handle);
$i = 1;
while (ftell($handle) < $final_length)
{
fwrite($handle, $dataToBeAdded );
$dataToBeAdded = $existingData ;
$existingData = fread($handle, strlen($dataToBeAdded ));
fseek($handle, $i * strlen($dataToBeAdded ));
$i++;
}
?>

How to overwrite a particular line in flat file?

My text file contains:
a
b
c
d
e
I can't figure out how to amend my code so that I can overwrite line 3 ONLY (ie replacing "c") with whatever I type into the input box 'data'. My code is as follows, currently the contents of the input box 'data' replaces my file entirely:
$data = $_POST['data'];
$file = "data.txt";
$fp = fopen($file, "w") or die("Couldn't open $file for writing");
fwrite($fp, $data) or die("Couldn't write values to file");
fclose($fp);
I have it working the other way around, ie the code below reads line 3 ONLY into the text box when the page first loads:
$file = "data.txt";
$lines = file( $file );
echo stripslashes($lines[2]);
Can anybody advise the code I need to use to achieve this?
The only way is to read the whole file, change the 3rd line, then write it all back out. Basically, like so:
$lines = file($file);
$lines[2] = $_POST['data'];
file_put_contents($file, implode("\n", $lines));
Btw, your reading code does not "ONLY" read line 3 - it reads all lines as per file() and then you only use line 3.

Writing some data to a specific area within a file in PHP

I'm experimenting with fopen for the first time and was wondering if it was possible to search for a particular section within a file before adding or replacing that content with data?
Ideally, I'd like to:
Use fopen to get the file
Search for a comment called <!-- test -->
Replace that comment with new data.
This possible? (for the record - Appending data to the end of the file or adding new data to a specific line number would not work for what I'm working on as the file is constantly changing).
Thanks!
<?php
// make sure radio is set
if( isset($_POST['enableSocialIcons']) )
{
// Open file for read and string modification
$file = "/test";
$fh = fopen($file, 'r+');
$contents = fread($fh, filesize($file));
$new_contents = str_replace("hello world", "hello", $contents);
fclose($fh);
// Open file to write
$fh = fopen($file, 'r+');
fwrite($fh, $new_contents);
fclose($fh);
}
?>
From: http://www.php.net/manual/en/function.fopen.php#81325
EDIT: To see what exactly is getting sent by your form do this at the top of the PHP file you're posting to:
<?php
echo '<pre>';
print_r($_POST);
echo '</pre>';
exit;
?>
If you read the entire file in then use something str_replace to make the change, you should be able to get what you want.

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