18.2. Creating a Temporary File
Problem
You need a file to temporarily hold some data.
Solution
Use tmpfile( )
if the file needs to last only the duration
of the running script:
$temp_fh = tmpfile(); // write some data to the temp file fputs($temp_fh,"The current time is ".strftime('%c')); // the file goes away when the script ends exit(1);
If the file needs to last longer, generate a filename with
tempnam( )
, and then use fopen( )
:
$tempfilename = tempnam('/tmp','data-'); $temp_fh = fopen($tempfilename,'w') or die($php_errormsg); fputs($temp_fh,"The current time is ".strftime('%c')); fclose($temp_fh) or die($php_errormsg);
Discussion
The function tmpfile( )
creates a file with a
unique name and returns a file handle. The file is removed when
fclose( )
is called on that file handle, or the
script ends.
Alternatively, tempnam( )
generates a filename. It
takes two arguments: the first is a directory, and the second is a
prefix for the filename. If the directory doesn’t
exist or isn’t writeable, tempnam( )
uses the system temporary directory — the
TMPDIR
environment variable in Unix or the
TMP
environment variable in Windows. For example:
$tempfilename = tempnam('/tmp','data-');
print "Temporary data will be stored in $tempfilename";
Temporary data will be stored in /tmp/data-GawVoL
Because of the way PHP generates temporary filenames, the filename
tempnam( )
returns is actually created but left empty, even if your script never explicitly opens the file. This ensures another program ...
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