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Home Backend Development PHP Tutorial php新建文件自動(dòng)編號(hào)的思路與實(shí)現(xiàn)_php技巧

php新建文件自動(dòng)編號(hào)的思路與實(shí)現(xiàn)_php技巧

May 17, 2016 am 09:18 AM
Automatic numbering

要求:在系統(tǒng)中 在新建文件是可以實(shí)現(xiàn)自動(dòng)編號(hào)。比如新建文本文件 默認(rèn)文件名是:新建 文本文檔.txt,如果繼續(xù)新建時(shí)文件名自動(dòng)變了:新建 文本文檔 (2).txt, 以后就是 3,4,5….請問這種算法用PHP怎么實(shí)現(xiàn)。
思路,原來想用循環(huán)來做,后來想想,用計(jì)數(shù)器遞增吧,簡單高效,這個(gè)TME可以是數(shù)據(jù)庫,可以文件,可以是配置文件,看你怎么做了,循環(huán)只是在維護(hù)的時(shí)候使用的,如果每建一個(gè)新文件也得循環(huán)一次,那得累死,緩存無處不在

復(fù)制代碼 代碼如下:

$dir="/web/csp/images/test/";
if(!file_exists($dir.'cache.txt')){
file_put_contents($dir.'cache.txt',1);
file_put_contents($dir.'新建文件.txt','');
}else{
$num = file_get_contents($dir.'cache.txt');
$num ++ ;
$name = '新建文件 ('.$num.').txt';
file_put_contents($dir.'cache.txt',$num);
file_put_contents($dir.$name,'');
}?>

銀子童鞋重寫后的
復(fù)制代碼 代碼如下:

function createFile($filename, $content = '')
{
if(file_exists($filename . '.tmp'))
{
$num = (int) file_get_contents($filename . '.tmp') + 1;
$fileinfo = pathinfo($filename);
file_put_contents($fileinfo['filename'] . '(' . $num . ').' .$fileinfo['extension'], $content);
file_put_contents($filename . '.tmp', $num);
}
else
{
file_put_contents($filename, $content);
file_put_contents($filename . '.tmp', 1);
}
}
createFile('test.txt');
?>

第三種,循環(huán)的
復(fù)制代碼 代碼如下:


$files = scandir('.'); //此代碼在web根目錄下寫就
$num = 0;
$str = '新建 文本文檔';
foreach ($files as $k=> $file) {
if (is_file($file) && preg_match('/(.*)\((\d+)\)\.txt/', $file, $matched)) {
$num = $matched[2]>$num ? $matched[2] : $num;
}
}
$filename = $num == 0 ? $str . '(1).txt' : $str . '(' . ($num+1) . ').txt';
if (fopen($filename, 'w')) {
echo '成功創(chuàng)建文件:' . $filename;
}
?>

以下是網(wǎng)友的回復(fù):
1.關(guān)于第一段代碼的.
在自動(dòng)新建幾個(gè)文件之后,
比如:現(xiàn)在的新建出來的文件有
新建文件.txt
新建文件 (2).txt
新建文件 (3).txt
這三個(gè)文件,如果這個(gè)時(shí)候刪除了
新建文件 (2).txt
新建文件 (3).txt
這兩個(gè),然后再執(zhí)行那個(gè)PHP,因?yàn)镃ache.txt計(jì)數(shù)的問題,再執(zhí)行的時(shí)候新建的文件是
新建文件 (4).txt
并沒有智能的根據(jù)序列創(chuàng)建.
而上面的操作,在Windows下的結(jié)果 新建出來的文件名應(yīng)該是
新建文件 (2).txt

2.關(guān)于第二段的.
首先,肯定也存在上面的問題,而更為嚴(yán)重的是,創(chuàng)建出來的文件,文件名與擴(kuò)展名的 . 分隔符丟了..
即:
test.txt
test(2)txt
test(3)txt
test(4)txt
究其原因是因?yàn)?在組合文件名的時(shí)候.沒有把擴(kuò)展名的點(diǎn)給加上去.
復(fù)制代碼 代碼如下:

file_put_contents($fileinfo['filename'] . '(' . $num . ')' .$fileinfo['extension'], $content);


來段更好玩的,更短的.
效率應(yīng)該會(huì)比上面的使用緩存(tmp文件)或者正則(preg_match)的好很多.
復(fù)制代碼 代碼如下:

$prefix = '新建 文本文檔';
$suffix = '.txt';
$t = $prefix.$suffix;//新建 文本文檔.txt
$i = 1;
while(file_exists($t)){//新建 文本文檔(\d+).txt
$t = $prefix.'('.++$i.')'.$suffix;
}
fclose(fopen($t, 'w'));
?>
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