php教程

fnmatch

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

fnmatch用模式匹配文件名

说明

fnmatch ( string $pattern , string $string [, int $flags = 0 ] ) : bool

fnmatch() 检查传入的 string 是否匹配给出的 shell 统配符 pattern

参数

pattern

shell 统配符。

string

要检查的字符串。 此函数对于文件名尤其有用,但也可以用于普通的字符串。

普通用户可能习惯于 shell 模式或者至少其中最简单的形式 '?''*' 通配符,因此使用 fnmatch() 来代替 preg_match() 来进行前端搜索表达式输入对于非程序员用户更加方便。

flags

The value of flags can be any combination of the following flags, joined with the binary OR (|) operator.

A list of possible flags for fnmatch()
Flag Description
FNM_NOESCAPE Disable backslash escaping.
FNM_PATHNAME Slash in string only matches slash in the given pattern.
FNM_PERIOD Leading period in string must be exactly matched by period in the given pattern.
FNM_CASEFOLD Caseless match. Part of the GNU extension.

返回值

匹配则返回 TRUE,否则返回 FALSE

更新日志

版本 说明
5.3.0 此函数开始在 Windows 平台上生效。

范例

Example #1 用 shell 中的通配符模式匹配来检查颜色名称

<?php
if (fnmatch("*gr[ae]y"$color)) {
  echo 
"some form of gray ...";
}
?>

注释

Warning

目前该函数无法在 Windows 或其它非 POSIX 兼容的系统上使用。

参见

  • glob() - 寻找与模式匹配的文件路径
  • preg_match() - 执行匹配正则表达式
  • sscanf() - 根据指定格式解析输入的字符
  • printf() - 输出格式化字符串
  • sprintf() - Return a formatted string

User Contributed Notes

bwilcock at gmail dot com 13-Nov-2013 03:49
fnmatch is not 100% reliable. Bug 14185 is still open and may or may not have been patched.

In certain wildcard circumstance fnmatch("*needle*", $haystack, match) returns false intermittantly

However stripos or preg returns a "find".
bernd dot ebert at gmx dot net 13-Jul-2012 11:21
There is a problem within the  pcre_fnmatch-Function concerning backslashes. Those will be masked by preq_quote and ADDITONALLY by the strtr if FN_NOESCAPE is not set -> something like "*a(*" will finally result in "#^.*a\\(.*$#". Note the double backslash which effectively does NOT mask the "(" correctly.
 
Since preq_quote always matches a backslash I don't think that this'll work with using preg_quote at all.
me at rowanlewis dot com 30-Sep-2010 10:58
Here's a definitive solution, which supports negative character classes and the four documented flags.

<?php
   
   
if (!function_exists('fnmatch')) {
       
define('FNM_PATHNAME', 1);
       
define('FNM_NOESCAPE', 2);
       
define('FNM_PERIOD', 4);
       
define('FNM_CASEFOLD', 16);
       
        function
fnmatch($pattern, $string, $flags = 0) {
            return
pcre_fnmatch($pattern, $string, $flags);
        }
    }
   
    function
pcre_fnmatch($pattern, $string, $flags = 0) {
       
$modifiers = null;
       
$transforms = array(
           
'\*'    => '.*',
           
'\?'    => '.',
           
'\[\!'    => '[^',
           
'\['    => '[',
           
'\]'    => ']',
           
'\.'    => '\.',
           
'\\'    => '\\\\'
       
);
       
       
// Forward slash in string must be in pattern:
       
if ($flags & FNM_PATHNAME) {
           
$transforms['\*'] = '[^/]*';
        }
       
       
// Back slash should not be escaped:
       
if ($flags & FNM_NOESCAPE) {
            unset(
$transforms['\\']);
        }
       
       
// Perform case insensitive match:
       
if ($flags & FNM_CASEFOLD) {
           
$modifiers .= 'i';
        }
       
       
// Period at start must be the same as pattern:
       
if ($flags & FNM_PERIOD) {
            if (
strpos($string, '.') === 0 && strpos($pattern, '.') !== 0) return false;
        }
       
       
$pattern = '#^'
           
. strtr(preg_quote($pattern, '#'), $transforms)
            .
'$#'
           
. $modifiers;
       
        return (boolean)
preg_match($pattern, $string);
    }
   
?>

This probably needs further testing, but it seems to function identically to the native fnmatch implementation.
Sinured 19-Mar-2008 01:04
An addition to my previous note: My statement regarding the FNM_* constants was wrong. They are available on POSIX-compliant systems (in other words, if fnmatch() is defined).
theboydanny at gmail dot com 29-Nov-2007 10:31
About the windows compat functions below:
I needed fnmatch for a application that had to work on Windows, took a look here and tested both. Jk's works for me, soywiz didn't (on WinXPSP2, PHP 5.2.3).
The only difference between them is addcslashes (soywiz) instead of preg_quote (jk). They _should_ both work, but for some reason soywiz's didn't for me. So YMMV.
However, to make JK's fnmatch() work with the example in the documentation, you also have to strtr the [ and ] in $pattern.
<?php
$pattern
= strtr(preg_quote($pattern, '#'), array('\*' => '.*', '\?' => '.', '\[' => '[', '\]' => ']'));
?>
And thanks for the functions, guys.
Sinured 30-Jul-2007 10:14
Possible flags (scratched out of fnmatch.h):
...::...

FNM_PATHNAME:
> Slash in $string only matches slash in $pattern.

FNM_PERIOD:
> Leading period in $string must be exactly matched by period in $pattern.

FNM_NOESCAPE:
> Disable backslash escaping.

FNM_NOSYS:
> Obsolescent.

FNM_FILE_NAME:
> Alias of FNM_PATHNAME.

FNM_LEADING_DIR:
> From fnmatch.h: /* Ignore `/...' after a match.  */

FNM_CASEFOLD:
> Caseless match.

Since they're appearing in file.c, but are not available in PHP, we'll have to define them ourselves:
<?php
define
('FNM_PATHNAME', 1);
define('FNM_PERIOD', 4);
define('FNM_NOESCAPE', 2);
// GNU extensions
define('FNM_FILE_NAME', FNM_PATHNAME);
define('FNM_LEADING_DIR', 8);
define('FNM_CASEFOLD', 16);
?>

I didn't test any of these except casefold, which worked for me.
Frederik Krautwald 12-Jun-2007 10:30
soywiz's function still doesn't seem to work -- at least not with PHP 5.2.3 on Windows -- but jk's does.
jk at ricochetsolutions dot com 13-Dec-2006 05:39
soywiz's function didnt seem to work for me, but this did.

<?php
if(!function_exists('fnmatch')) {

    function
fnmatch($pattern, $string) {
        return
preg_match("#^".strtr(preg_quote($pattern, '#'), array('\*' => '.*', '\?' => '.'))."$#i", $string);
    }
// end

} // end if
?>
phlipping at yahoo dot com 06-Aug-2003 03:59
you couls also try this function that I wrote before I found fnmatch:

function WildToReg($str)
{
  $s = "";  
  for ($i = 0; $i < strlen($str); $i++)
  {
   $c = $str{$i};
   if ($c =='?')
    $s .= '.'; // any character
   else if ($c == '*')   
    $s .= '.*'; // 0 or more any characters   
   else if ($c == '[' || $c == ']')
    $s .= $c;  // one of characters within []
   else
    $s .= '\\' . $c;
  }
  $s = '^' . $s . '$';

  //trim redundant ^ or $
  //eg ^.*\.txt$ matches exactly the same as \.txt$
  if (substr($s,0,3) == "^.*")
   $s = substr($s,3);
  if (substr($s,-3,3) == ".*$")
   $s = substr($s,0,-3);
  return $s;
}

if (ereg(WildToReg("*.txt"), $fn))
  print "$fn is a text file";
else
  print "$fn is not a text file";

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