* 相对路径 -> 绝对路径 realpath
<?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 = []; ??// divide 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, $st_fpos)); ???$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
这里直接realpath就可以了，为什么多此一举?
* 绝对路径 -> 相对路径
... [TO BE DONE]
PHP 相对路径转换为绝对路径 realpath
原文地址：https://www.cnblogs.com/mingzhanghui/p/9434337.html