Manpages - curl_easy_unescape.3

curl_easy_unescape - URL decodes the given string

#include <curl/curl.h>

char *curl_easy_unescape( CURL **/curl/, const char */url/ *, int */inlength/, int */outlength/ );*

This function converts the given URL encoded input string to a “plain string” and returns that in an allocated memory area. All input characters that are URL encoded (%XX where XX is a two-digit hexadecimal number) are converted to their binary versions.

If the length argument is set to 0 (zero), curl_easy_unescape(3) will use strlen() on the input url string to find out the size.

If outlength is non-NULL, the function will write the length of the returned string in the integer it points to. This allows an escaped string containing %00 to still get used properly after unescaping. Since this is a pointer to an int type, it can only return a value up to INT_MAX so no longer string can be unescaped if the string length is returned in this parameter.

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

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

Added in 7.15.4 and replaces the old curl_unescape(3) function.

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

*curl_easy_escape*(3), *curl_free*(3),*RFC*3986