1--- 2c: Copyright (C) Daniel Stenberg, <daniel.se>, et al. 3SPDX-License-Identifier: curl 4Title: curl_easy_unescape 5Section: 3 6Source: libcurl 7See-also: 8 - curl_easy_escape (3) 9 - curl_free (3) 10--- 11 12# NAME 13 14curl_easy_unescape - URL decodes the given string 15 16# SYNOPSIS 17 18~~~c 19#include <curl/curl.h> 20 21char *curl_easy_unescape(CURL *curl, const char *input, 22 int inlength, int *outlength); 23~~~ 24 25# DESCRIPTION 26 27This function converts the URL encoded string **input** to a "plain string" 28and returns that in an allocated memory area. All input characters that are URL 29encoded (%XX where XX is a two-digit hexadecimal number) are converted to their 30binary versions. 31 32If the **length** argument is set to 0 (zero), curl_easy_unescape(3) 33uses strlen() on **input** to find out the size. 34 35If **outlength** is non-NULL, the function writes the length of the returned 36string in the integer it points to. This allows proper handling even for 37strings containing %00. Since this is a pointer to an *int* type, it can 38only return a value up to *INT_MAX* so no longer string can be returned in 39this parameter. 40 41Since 7.82.0, the **curl** parameter is ignored. Prior to that there was 42per-handle character conversion support for some old operating systems such as 43TPF, but it was otherwise ignored. 44 45You must curl_free(3) the returned string when you are done with it. 46 47# EXAMPLE 48 49~~~c 50int main(void) 51{ 52 CURL *curl = curl_easy_init(); 53 if(curl) { 54 int decodelen; 55 char *decoded = curl_easy_unescape(curl, "%63%75%72%6c", 12, &decodelen); 56 if(decoded) { 57 /* do not assume printf() works on the decoded data! */ 58 printf("Decoded: "); 59 /* ... */ 60 curl_free(decoded); 61 } 62 curl_easy_cleanup(curl); 63 } 64} 65~~~ 66 67# AVAILABILITY 68 69Added in 7.15.4 and replaces the old curl_unescape(3) function. 70 71# RETURN VALUE 72 73A pointer to a null-terminated string or NULL if it failed. 74