I saw using fseek to insert string before last line this question, but this isn't solving my problem. I not use "?>" tag. Php version PHP 5.4
example line1
example line2
//i need insert here
lastline $eg};
My code is working but this is adding empty lines after all lines :
$filename = 'example.php';
$arr = file($filename);
if ($arr === false) {
die('Error' . $filename);
}
array_pop($arr);
file_put_contents($filename, implode(PHP_EOL, $arr));
/// I'm deleting last line here
$person = "my text here\n";
file_put_contents($filename, $person, FILE_APPEND);
$person = "andherelastline";
file_put_contents($filename, $person, FILE_APPEND);
//and then add again here
$file = "tmp/saf.txt";
$fc = fopen($file, "r");
while (!feof($fc)) {
$buffer = fgets($fc, 4096);
$lines[] = $buffer;
}
fclose($fc);
//open same file and use "w" to clear file
$f = fopen($file, "w") or die("couldn't open $file");
$lineCount = count($lines);
//loop through array writing the lines until the secondlast
for ($i = 0; $i < $lineCount- 1; $i++) {
fwrite($f, $lines[$i]);
}
fwrite($f, 'Your insert string here'.PHP_EOL);
//write the last line
fwrite($f, $lines[$lineCount-1]);
fclose($f);
Related
I want to read a file line by line, but without completely loading it in memory.
My file is too large to open in memory, and if try to do so I always get out of memory errors.
The file size is 1 GB.
You can use the fgets() function to read the file line by line:
$handle = fopen("inputfile.txt", "r");
if ($handle) {
while (($line = fgets($handle)) !== false) {
// process the line read.
}
fclose($handle);
}
if ($file = fopen("file.txt", "r")) {
while(!feof($file)) {
$line = fgets($file);
# do same stuff with the $line
}
fclose($file);
}
You can use an object oriented interface class for a file - SplFileObject http://php.net/manual/en/splfileobject.fgets.php (PHP 5 >= 5.1.0)
<?php
$file = new SplFileObject("file.txt");
// Loop until we reach the end of the file.
while (!$file->eof()) {
// Echo one line from the file.
echo $file->fgets();
}
// Unset the file to call __destruct(), closing the file handle.
$file = null;
If you want to use foreach instead of while when opening a big file, you probably want to encapsulate the while loop inside a Generator to avoid loading the whole file into memory:
/**
* #return Generator
*/
$fileData = function() {
$file = fopen(__DIR__ . '/file.txt', 'r');
if (!$file) {
return; // die() is a bad practice, better to use return
}
while (($line = fgets($file)) !== false) {
yield $line;
}
fclose($file);
};
Use it like this:
foreach ($fileData() as $line) {
// $line contains current line
}
This way you can process individual file lines inside the foreach().
Note: Generators require >= PHP 5.5
There is a file() function that returns an array of the lines contained in the file.
foreach(file('myfile.txt') as $line) {
echo $line. "\n";
}
The obvious answer wasn't there in all the responses.
PHP has a neat streaming delimiter parser available made for exactly that purpose.
$fp = fopen("/path/to/the/file", "r");
while (($line = stream_get_line($fp, 1024 * 1024, "\n")) !== false) {
echo $line;
}
fclose($fp);
Use buffering techniques to read the file.
$filename = "test.txt";
$source_file = fopen( $filename, "r" ) or die("Couldn't open $filename");
while (!feof($source_file)) {
$buffer = fread($source_file, 4096); // use a buffer of 4KB
$buffer = str_replace($old,$new,$buffer);
///
}
foreach (new SplFileObject(__FILE__) as $line) {
echo $line;
}
One of the popular solutions to this question will have issues with the new line character. It can be fixed pretty easy with a simple str_replace.
$handle = fopen("some_file.txt", "r");
if ($handle) {
while (($line = fgets($handle)) !== false) {
$line = str_replace("\n", "", $line);
}
fclose($handle);
}
This how I manage with very big file (tested with up to 100G). And it's faster than fgets()
$block =1024*1024;//1MB or counld be any higher than HDD block_size*2
if ($fh = fopen("file.txt", "r")) {
$left='';
while (!feof($fh)) {// read the file
$temp = fread($fh, $block);
$fgetslines = explode("\n",$temp);
$fgetslines[0]=$left.$fgetslines[0];
if(!feof($fh) )$left = array_pop($lines);
foreach ($fgetslines as $k => $line) {
//do smth with $line
}
}
}
fclose($fh);
Be careful with the 'while(!feof ... fgets()' stuff, fgets can get an error (returnfing false) and loop forever without reaching the end of file. codaddict was closest to being correct but when your 'while fgets' loop ends, check feof; if not true, then you had an error.
SplFileObject is useful when it comes to dealing with large files.
function parse_file($filename)
{
try {
$file = new SplFileObject($filename);
} catch (LogicException $exception) {
die('SplFileObject : '.$exception->getMessage());
}
while ($file->valid()) {
$line = $file->fgets();
//do something with $line
}
//don't forget to free the file handle.
$file = null;
}
<?php
echo '<meta charset="utf-8">';
$k= 1;
$f= 1;
$fp = fopen("texttranslate.txt", "r");
while(!feof($fp)) {
$contents = '';
for($i=1;$i<=1500;$i++){
echo $k.' -- '. fgets($fp) .'<br>';$k++;
$contents .= fgets($fp);
}
echo '<hr>';
file_put_contents('Split/new_file_'.$f.'.txt', $contents);$f++;
}
?>
Function to Read with array return
function read_file($filename = ''){
$buffer = array();
$source_file = fopen( $filename, "r" ) or die("Couldn't open $filename");
while (!feof($source_file)) {
$buffer[] = fread($source_file, 4096); // use a buffer of 4KB
}
return $buffer;
}
How to delete / clear lines of data if it reaches 100th line. I checked some examples, but it is not working.
I need to check the number of the line end if it reaches line number 100, delete or clear all in that text file.
The following code is taken from an example, but this is also not working:
<?php
$text = "log.txt";
$lines = explode("\n", $text);
$lines = array_slice($lines, 0, 10); //10 is how many lines you want to keep
$text = implode("\n", $lines);
?>
Something like this: you will need to take it and fit it to your application, but I think this is what you are looking for.
//Count lines
$file="largefile.txt";
$linecount = 0;
$handle = fopen($file, "r");
while(!feof($handle)){
$line = fgets($handle);
$linecount++;
}
fclose($handle);
//Remove lines
if ($linecount ==100)
{
$lines = file($file, FILE_IGNORE_NEW_LINES);
$remove = "balblalbllablab";
foreach($lines as $key => $line)
if(stristr($line, $remove)) unset($lines[$key]);
$data = implode('\n', array_values($lines));
$file = fopen($path);
fwrite($file, $data);
fclose($file);
}
I want to read a file line by line, but without completely loading it in memory.
My file is too large to open in memory, and if try to do so I always get out of memory errors.
The file size is 1 GB.
You can use the fgets() function to read the file line by line:
$handle = fopen("inputfile.txt", "r");
if ($handle) {
while (($line = fgets($handle)) !== false) {
// process the line read.
}
fclose($handle);
}
if ($file = fopen("file.txt", "r")) {
while(!feof($file)) {
$line = fgets($file);
# do same stuff with the $line
}
fclose($file);
}
You can use an object oriented interface class for a file - SplFileObject http://php.net/manual/en/splfileobject.fgets.php (PHP 5 >= 5.1.0)
<?php
$file = new SplFileObject("file.txt");
// Loop until we reach the end of the file.
while (!$file->eof()) {
// Echo one line from the file.
echo $file->fgets();
}
// Unset the file to call __destruct(), closing the file handle.
$file = null;
If you want to use foreach instead of while when opening a big file, you probably want to encapsulate the while loop inside a Generator to avoid loading the whole file into memory:
/**
* #return Generator
*/
$fileData = function() {
$file = fopen(__DIR__ . '/file.txt', 'r');
if (!$file) {
return; // die() is a bad practice, better to use return
}
while (($line = fgets($file)) !== false) {
yield $line;
}
fclose($file);
};
Use it like this:
foreach ($fileData() as $line) {
// $line contains current line
}
This way you can process individual file lines inside the foreach().
Note: Generators require >= PHP 5.5
There is a file() function that returns an array of the lines contained in the file.
foreach(file('myfile.txt') as $line) {
echo $line. "\n";
}
The obvious answer wasn't there in all the responses.
PHP has a neat streaming delimiter parser available made for exactly that purpose.
$fp = fopen("/path/to/the/file", "r");
while (($line = stream_get_line($fp, 1024 * 1024, "\n")) !== false) {
echo $line;
}
fclose($fp);
Use buffering techniques to read the file.
$filename = "test.txt";
$source_file = fopen( $filename, "r" ) or die("Couldn't open $filename");
while (!feof($source_file)) {
$buffer = fread($source_file, 4096); // use a buffer of 4KB
$buffer = str_replace($old,$new,$buffer);
///
}
foreach (new SplFileObject(__FILE__) as $line) {
echo $line;
}
One of the popular solutions to this question will have issues with the new line character. It can be fixed pretty easy with a simple str_replace.
$handle = fopen("some_file.txt", "r");
if ($handle) {
while (($line = fgets($handle)) !== false) {
$line = str_replace("\n", "", $line);
}
fclose($handle);
}
This how I manage with very big file (tested with up to 100G). And it's faster than fgets()
$block =1024*1024;//1MB or counld be any higher than HDD block_size*2
if ($fh = fopen("file.txt", "r")) {
$left='';
while (!feof($fh)) {// read the file
$temp = fread($fh, $block);
$fgetslines = explode("\n",$temp);
$fgetslines[0]=$left.$fgetslines[0];
if(!feof($fh) )$left = array_pop($lines);
foreach ($fgetslines as $k => $line) {
//do smth with $line
}
}
}
fclose($fh);
Be careful with the 'while(!feof ... fgets()' stuff, fgets can get an error (returnfing false) and loop forever without reaching the end of file. codaddict was closest to being correct but when your 'while fgets' loop ends, check feof; if not true, then you had an error.
SplFileObject is useful when it comes to dealing with large files.
function parse_file($filename)
{
try {
$file = new SplFileObject($filename);
} catch (LogicException $exception) {
die('SplFileObject : '.$exception->getMessage());
}
while ($file->valid()) {
$line = $file->fgets();
//do something with $line
}
//don't forget to free the file handle.
$file = null;
}
<?php
echo '<meta charset="utf-8">';
$k= 1;
$f= 1;
$fp = fopen("texttranslate.txt", "r");
while(!feof($fp)) {
$contents = '';
for($i=1;$i<=1500;$i++){
echo $k.' -- '. fgets($fp) .'<br>';$k++;
$contents .= fgets($fp);
}
echo '<hr>';
file_put_contents('Split/new_file_'.$f.'.txt', $contents);$f++;
}
?>
Function to Read with array return
function read_file($filename = ''){
$buffer = array();
$source_file = fopen( $filename, "r" ) or die("Couldn't open $filename");
while (!feof($source_file)) {
$buffer[] = fread($source_file, 4096); // use a buffer of 4KB
}
return $buffer;
}
If I have a CSV saved on a server, how can I use PHP to write a given line, say 142,fred,elephants to the bottom of it?
Open the CSV file for appending (fopenDocs):
$handle = fopen("test.csv", "a");
Then add your line (fputcsvDocs):
fputcsv($handle, $line); # $line is an array of strings (array|string[])
Then close the handle (fcloseDocs):
fclose($handle);
You can use an object oriented interface class for a file - SplFileObject http://php.net/manual/en/splfileobject.fputcsv.php (PHP 5 >= 5.4.0)
$file = new SplFileObject('file.csv', 'a');
$file->fputcsv(array('aaa', 'bbb', 'ccc', 'dddd'));
$file = null;
This solution works for me:
<?php
$list = array
(
'Peter,Griffin,Oslo,Norway',
'Glenn,Quagmire,Oslo,Norway',
);
$file = fopen('contacts.csv','a'); // 'a' for append to file - created if doesn't exit
foreach ($list as $line)
{
fputcsv($file,explode(',',$line));
}
fclose($file);
?>
Ref: https://www.w3schools.com/php/func_filesystem_fputcsv.asp
If you want each split file to retain the headers of the original; this is the modified version of hakre's answer:
$inputFile = './users.csv'; // the source file to split
$outputFile = 'users_split'; // this will be appended with a number and .csv e.g. users_split1.csv
$splitSize = 10; // how many rows per split file you want
$in = fopen($inputFile, 'r');
$headers = fgets($in); // get the headers of the original file for insert into split files
// No need to touch below this line..
$rowCount = 0;
$fileCount = 1;
while (!feof($in)) {
if (($rowCount % $splitSize) == 0) {
if ($rowCount > 0) {
fclose($out);
}
$out = fopen($outputFile . $fileCount++ . '.csv', 'w');
fputcsv($out, explode(',', $headers));
}
$data = fgetcsv($in);
if ($data)
fputcsv($out, $data);
$rowCount++;
}
fclose($out);
In PHP if you write to a file it will write end of that existing file.
How do we prepend a file to write in the beginning of that file?
I have tried rewind($handle) function but seems overwriting if current content is larger than existing.
Any Ideas?
$prepend = 'prepend me please';
$file = '/path/to/file';
$fileContents = file_get_contents($file);
file_put_contents($file, $prepend . $fileContents);
The file_get_contents solution is inefficient for large files. This solution may take longer, depending on the amount of data that needs to be prepended (more is actually better), but it won't eat up memory.
<?php
$cache_new = "Prepend this"; // this gets prepended
$file = "file.dat"; // the file to which $cache_new gets prepended
$handle = fopen($file, "r+");
$len = strlen($cache_new);
$final_len = filesize($file) + $len;
$cache_old = fread($handle, $len);
rewind($handle);
$i = 1;
while (ftell($handle) < $final_len) {
fwrite($handle, $cache_new);
$cache_new = $cache_old;
$cache_old = fread($handle, $len);
fseek($handle, $i * $len);
$i++;
}
?>
$filename = "log.txt";
$file_to_read = #fopen($filename, "r");
$old_text = #fread($file_to_read, 1024); // max 1024
#fclose(file_to_read);
$file_to_write = fopen($filename, "w");
fwrite($file_to_write, "new text".$old_text);
Another (rough) suggestion:
$tempFile = tempnam('/tmp/dir');
$fhandle = fopen($tempFile, 'w');
fwrite($fhandle, 'string to prepend');
$oldFhandle = fopen('/path/to/file', 'r');
while (($buffer = fread($oldFhandle, 10000)) !== false) {
fwrite($fhandle, $buffer);
}
fclose($fhandle);
fclose($oldFhandle);
rename($tempFile, '/path/to/file');
This has the drawback of using a temporary file, but is otherwise pretty efficient.
When using fopen() you can set the mode to set the pointer (ie. the begginng or end.
$afile = fopen("file.txt", "r+");
'r' Open for reading only; place
the file pointer at the beginning of
the file.
'r+' Open for reading and
writing; place the file pointer at the
beginning of the file.
$file = fopen('filepath.txt', 'r+') or die('Error');
$txt = "/n".$string;
fwrite($file, $txt);
fclose($file);
This will add a blank line in the text file, so next time you write to it you replace the blank line. with a blank line and your string.
This is the only and best trick.