Code instance where PHP converts a relative path to an absolute path via Realpath

This article brings you the content is about PHP through the Realpath to convert the relative path to absolute path code example, there is a certain reference value, the need for friends can refer to, I hope to help you.

Absolute path, relative path:

<?php/** * @param string $in _rel:relative directory * @param string $out _abs:absolute directory */define (' Path_max ',  255); function Sub_rel2abs (String $in _rel, String & $out _abs) {$i _rtn = 0;  return value $ss _rel = "";    For relative path build $st _fpos = 0;   Front Separator index $SV _path = [];    Pide path to array $st _pos = Strpos ($in _rel, directory_separator);    $npos = 0; while ($npos! = $st _pos) {if ($st _pos! = 0) {Array_push ($sv _path, substr ($in _rel, $st _fpos, $st _pos-        $st _fpos));   }//next ... $st _fpos = $st _pos;            Set current pos-to-last POS $st _pos++;  From next index $st _pos = Strpos ($in _rel, Directory_separator, $st _pos); Next separator Index}//while ($npos! = $st _pos)//FINAL separator Array_push ($sv _path, substr ($in _rel, $st _f     POS));    $LPC = 0;    Loop count $i _max = count ($sv _path); while ($LPC < $i _max && 0 = = = $i _rtn) {$ss_rel. = $sv _path[$LPC];//relative path = relative path $c _abs = Realpath ($ss _rel);        if ($c _abs = = = False) {$i _rtn =-1;            } else {$ss _rel = $c _abs;        $i _rtn = 0;    } $LPC + +;  }//while (count ($sv _path) >0)//Normal ending if (0=== $i _rtn) {$out _abs = $ss _rel; Set converted path} return $i _rtn;} Test$indir = "/users/mch/code/php/directory"; Is_dir ($inDir) | | mkdir ($inDir, 0777, true); $WD = __dir__;chdir ($inDir); $out = ""; Echo sub_rel2abs (".. /.. /.. /eclipse-workspace/blog.zip ", $out). Php_eol;echo $out. Php_eol; ChDir ($WD); @rmdir ($inDir);? >

Output

0/users/mch/eclipse-workspace/blog.zip

Here directly realpath can, why superfluous?