tempnam
Beware that PHP's tmpfile is not an equivalent of unix' tmpfile.
PHP (at least v. 5.3.17/linux I'm using now) creates a file in /tmp with prefix "php", and deletes that file on fclose or script termination.
So, if you want to be sure that you don't leave garbage even in case of a fatal error, or killed process, you shouldn't rely on this function.
Use the classical method of deleting the file after creation:
<?php
$fn = tempnam ('/tmp', 'some-prefix-');
if ($fn)
{
$f = fopen ($fn, 'w+');
unlink ($fn); // even if fopen failed, because tempnam created the file
if ($f)
{
do_something_with_file_handle ($f);
}
}
?>
tmpfile
(PHP 4, PHP 5)
tmpfile — Creates a temporary file
Description
resource tmpfile
( void
)
Creates a temporary file with a unique name in read-write (w+) mode and returns a file handle .
The file is automatically removed when closed (using fclose()), or when the script ends.
For details, consult your system documentation on the tmpfile(3) function, as well as the stdio.h header file.
Return Values
Returns a file handle, similar to the one returned by
fopen(), for the new file or FALSE on failure.
Examples
Example #1 tmpfile() example
<?php
$temp = tmpfile();
fwrite($temp, "writing to tempfile");
fseek($temp, 0);
echo fread($temp, 1024);
fclose($temp); // this removes the file
?>
The above example will output:
writing to tempfile
See Also
- tempnam() - Create file with unique file name
- sys_get_temp_dir() - Returns directory path used for temporary files
add a note
User Contributed Notes
tmpfile - [9 notes]
ssandor ¶
5 months ago
kexianbin at diyism dot com ¶
9 months ago
If you want to specify the extension name of tmp file:
<?php
$tmp=array_search('uri', @array_flip(stream_get_meta_data($GLOBALS[mt_rand()]=tmpfile())));
rename($tmp, $tmp.='.png');
register_shutdown_function(create_function('', "unlink('{$tmp}');"));
?>
oremanj at gmail dot com ¶
6 years ago
No, the fseek() is necessary - after writing to the file, the file pointer (I'll use "file pointer" to refer to the current position in the file, the thing you change with fseek()) is at the end of the file, and reading at the end of the file gives you EOF right away, which manifests itself as an empty upload.
Where you might be getting confused is in some systems' requirement that one seek or flush between reading and writing the same file. fflush() satisfies that prerequisite, but it doesn't do anything about the file pointer, and in this case the file pointer needs moving.
-- Josh
kexianbin at diyism dot com ¶
1 year ago
A clean method to use temporary file:
<?php
$tmp=array_search('uri', @array_flip(stream_get_meta_data($GLOBALS[mt_rand()]=tmpfile())));
file_put_contents($tmp, 'hello');
echo file_get_contents($tmp);
?>
without need to fclose the tmp file, it will be deleted while the php ends.
Anonymous ¶
6 years ago
fseek() is important because if you forget about it you will upload empty file...
i had sth like that ^_^
chris [at] pureformsolutions [dot] com ¶
7 years ago
I found this function useful when uploading a file through FTP. One of the files I was uploading was input from a textarea on the previous page, so really there was no "file" to upload, this solved the problem nicely:
<?php
# Upload setup.inc
$fSetup = tmpfile();
fwrite($fSetup,$setup);
fseek($fSetup,0);
if (!ftp_fput($ftp,"inc/setup.inc",$fSetup,FTP_ASCII)) {
echo "<br /><i>Setup file NOT inserted</i><br /><br />";
}
fclose($fSetup);
?>
The $setup variable is the contents of the textarea.
And I'm not sure if you need the fseek($temp,0); in there either, just leave it unless you know it doesn't effect it.
Anonymous ¶
6 years ago
By the way, this function is really useful for libcurl's CURLOPT_PUT feature if what you're trying to PUT is a string. For example:
<?php
/* Create a cURL handle. */
$ch = curl_init();
/* Prepare the data for HTTP PUT. */
$putString = "Hello, world!";
$putData = tmpfile();
fwrite($putData, $putString);
fseek($putData, 0);
/* Set cURL options. */
curl_setopt($ch, CURLOPT_URL, "http://www.example.com");
curl_setopt($ch, CURLOPT_PUT, true);
curl_setopt($ch, CURLOPT_INFILE, $putData);
curl_setopt($ch, CURLOPT_INFILESIZE, strlen($putString));
/* ... (other curl options) ... */
/* Execute the PUT and clean up */
$result = curl_exec($ch);
fclose($putData);
curl_close($ch);
?>
o_O Tync ¶
6 years ago
Remember, that open_basedir affects this function. You will get an error:
Warning: tmpfile() [function.tmpfile]: open_basedir restriction in effect. File(/var/tmp) is not within the allowed path(s): ....blablabla =)
zlynx at acm dot org ¶
6 years ago
I am fairly sure that the seek just flushes the data from the memory buffers to the file. fflush() should give you the same effect.