我之前问过一个问题(如何防止该计数器重置为 100,000? https://stackoverflow.com/questions/5250118/how-to-keep-this-counter-from-reseting-at-100-000),现在有一个后续问题。
我有另一个版本的计数器,可以被告知在某个数字处重置,我想确保第二个版本没有与第一个版本相同的问题。
我现在编码的是:
$reset = '10';
$filename4 = "$some_variable/$filename3.txt";
// Open our file in append-or-create mode.
$fh = fopen($filename4, "a+");
if (!$fh)
die("unable to create file");
if ($reset == 'default'){
// Before doing anything else, get an exclusive lock on the file.
// This will prevent anybody else from reading or writing to it.
flock($fh, LOCK_EX);
// Place the pointer at the start of the file.
fseek($fh, 0);
// Read one line from the file, then increment the number.
// There should only ever be one line.
$current = 1 + intval(trim(fgets($fh)));
// Now we can reset the pointer again, and truncate the file to zero length.
fseek($fh, 0);
ftruncate($fh, 0);
// Now we can write out our line.
fwrite($fh, $current . "\n");
// And we're done. Closing the file will also release the lock.
fclose($fh);
}
else {
$current = trim(file_get_contents($filename4)) + 1;
if($current >= $reset) {
$new = '0';
fwrite(fopen($filename4, 'w'), $new);
}
else {
fwrite(fopen($filec, 'w'), $current);
}
}
echo $current;
我不想假设我知道要对此代码进行哪些更改,所以我发布了另一个问题。编辑-如果 $reset 不等于默认值,我应该在此处进行哪些更改以避免无法获得文件的独占锁定?编写此代码的正确方法是什么?这行得通吗?:
$filename4 = "$some_variable/$filename3.txt";
// Open our file in append-or-create mode.
$fh = fopen($filename4, "a+");
if (!$fh)
die("unable to create file");
// Before doing anything else, get an exclusive lock on the file.
// This will prevent anybody else from reading or writing to it.
flock($fh, LOCK_EX);
// Place the pointer at the start of the file.
fseek($fh, 0);
if ($reset == 'default'){
// Read one line from the file, then increment the number.
// There should only ever be one line.
$current = 1 + intval(trim(fgets($fh)));
} else {
// Read one line from the file, then increment the number.
// There should only ever be one line.
$current = 1 + intval(trim(fgets($fh)));
if($current >= $reset) {
$current = '0';
}
else {
// Read one line from the file, then increment the number.
// There should only ever be one line.
$current = 1 + intval(trim(fgets($fh)));
}
}
// Now we can reset the pointer again, and truncate the file to zero length.
fseek($fh, 0);
ftruncate($fh, 0);
// Now we can write out our line.
fwrite($fh, $current . "\n");
// And we're done. Closing the file will also release the lock.
fclose($fh);
echo $current;
编辑-这似乎对我有用:
$reset = "default";
$filename4 = "counter.txt";
// Open our file in append-or-create mode.
$fh = fopen($filename4, "a+");
if (!$fh)
die("unable to create file");
// Before doing anything else, get an exclusive lock on the file.
// This will prevent anybody else from reading or writing to it.
flock($fh, LOCK_EX);
// Place the pointer at the start of the file.
fseek($fh, 0);
// Read one line from the file, then increment the number.
// There should only ever be one line.
$current = 1 + intval(trim(fgets($fh)));
if ($reset == 'default'){
$new = $current;
} else {
if($current >= ($reset + '1')) {
$new = '1';
}
else {
$new = $current;
}
}
// Now we can reset the pointer again, and truncate the file to zero length.
fseek($fh, 0);
ftruncate($fh, 0);
// Now we can write out our line.
fwrite($fh, $new . "\n");
// And we're done. Closing the file will also release the lock.
fclose($fh);
echo $new;
这看起来合适吗?