I want to validate a file name Name of file or folder should not contain \ / ? % * : | " < > . Could you please suggest me the regex expression to use in preg_match()? Thanks.

It would be more efficient to use the strpbrk() function. <pre class="prettyprint"><code>if (strpbrk($filename, "\\/?%*:|\"<>") === FALSE) { /* $filename is legal; doesn't contain illegal character. */ } else { /* $filename contains at least one illegal character. */ } </code></pre>

The regex that meets your requirements: <code>^[^\\/?%*:|"<>\.]+$</code>

regex for validating folder name & file name

2 Answers

It would be more efficient to use the strpbrk() function.

if (strpbrk($filename, "\\/?%*:|\"<>") === FALSE) {
  /* $filename is legal; doesn't contain illegal character. */
}
else {
  /* $filename contains at least one illegal character. */
}