curl_unescape(3)

curl_unescape3

Url decode a string

Usage

#include <curl/curl.h>
char *curl_unescape(const char *input, int length);

Overview

Deprecated. Use curl_easy_unescape(3) instead.

This function converts the URL encoded string input to a "plain string" and return that as a new allocated string. All input characters that are URL encoded (%XX where XX is a two-digit hexadecimal number) are converted to their plain text versions. Although not constrained by its type, the returned data may not be altered.

If the length argument is set to 0, curl_unescape(3) calls strlen() on input to find out the size.

You must curl_free(3) the returned string when you are done with it.

Protocols

This functionality affects all supported protocols

Examples

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    char *decoded = curl_unescape("%63%75%72%6c", 12);
    if(decoded) {
      /* do not assume printf() works on the decoded data */
      printf("Decoded: ");
      /* ... */
      curl_free(decoded);
    }
  }
}

Deprecated

Since 7.15.4, curl_easy_unescape(3) should be used. This function might be removed in a future release.

Return value

A pointer to a null-terminated string or NULL if it failed.

Releases

13 releases since Debian 3.0 (Woody); the text changed 11 times.

  1. 3.0
  2. 3.1
  3. 4.0–5.0
  4. 6.0
  5. 7
  6. 8
  7. 9
  8. 10
  9. 11
  10. 12
  11. 13
  12. Arch

Availability

Added in curl 7.1

From curl 8.23.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.