代码:
$tmp_file_path = '/path/to/tmp/file';
// move file from tmp dir
$new_file_path = '/path/to/new/location/file';
while(file_exists($new_file_path)){
$new_file_path = $new_file_path . microtime(true);
usleep(100000);
}
// HERE ANOTHER INSTANCE OF THIS SCRIPT COULD HAVE ALREADY TAKEN NEW NAME,
// $new_file_path
// BUT NEXT CALL TO rename function OVERWRITES IT WITH NEW CONTENT!
rename($tmp_file_path, $new_file_path ); //Attempts to rename oldname to newname,
// moving it between directories if necessary. If newname exists, it will be
// overwritten.
在PHP中有什么解决方案使file_exists函数创建一个文件，如果它不存在，像touch一样，在一个原子操作中?
PHP有tempnam函数:
// create a file with unique name in $new_file_path
$new_file_path = '/path/to/new/location';
$tmpfname = tempnam($new_file_path, "foo");
根据手册:
tempnam创建一个具有唯一文件名的文件，访问权限设置为0600，在指定的目录下。如果目录不存在，tempnam()可能会在系统的临时目录中生成一个文件，并且返回它的名称