xref: /aosp_15_r20/external/curl/docs/libcurl/curl_easy_unescape.md (revision 6236dae45794135f37c4eb022389c904c8b0090d)

---
c: Copyright (C) Daniel Stenberg, <[email protected]>, et al.
SPDX-License-Identifier: curl
Title: curl_easy_unescape
Section: 3
Source: libcurl
See-also:
  - curl_easy_escape (3)
  - curl_url_get (3)
Protocol:
  - All
Added-in: 7.15.4
---

# NAME

curl_easy_unescape - URL decode a string

# SYNOPSIS

~~~c
#include <curl/curl.h>

char *curl_easy_unescape(CURL *curl, const char *input,
                         int inlength, int *outlength);
~~~

# DESCRIPTION

This function converts the URL encoded string **input** 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)
uses strlen() on **input** to find out the size.

If **outlength** is non-NULL, the function writes the length of the returned
string in the integer it points to. This allows proper handling even for
strings containing %00. 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 returned in
this parameter.

Since 7.82.0, the **curl** parameter is ignored. Prior to that there was
per-handle character conversion support for some old operating systems such as
TPF, but it was otherwise ignored.

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

# %PROTOCOLS%

# EXAMPLE

~~~c
int main(void)
{
  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);
    }
    curl_easy_cleanup(curl);
  }
}
~~~

# %AVAILABILITY%

# RETURN VALUE

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