curl/docs/libcurl/curl_easy_unescape.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" * SPDX-License-Identifier: curl
.\" *
.\" **************************************************************************
.\"
.TH curl_easy_unescape 3 "7 April 2006" "libcurl" "libcurl"
.SH NAME
curl_easy_unescape - URL decodes the given string
.SH SYNOPSIS
.nf
#include <curl/curl.h>

char *curl_easy_unescape(CURL *curl, const char *input,
                         int inlength, int *outlength);
.fi
.SH DESCRIPTION
This function converts the URL encoded string \fBinput\fP 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 \fBlength\fP argument is set to 0 (zero), \fIcurl_easy_unescape(3)\fP
uses strlen() on \fBinput\fP to find out the size.

If \fBoutlength\fP 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 \fIint\fP type, it can
only return a value up to \fIINT_MAX\fP so no longer string can be returned in
this parameter.

Since 7.82.0, the \fBcurl\fP 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 \fIcurl_free(3)\fP the returned string when you are done with it.
.SH EXAMPLE
.nf
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);
}
.fi
.SH AVAILABILITY
Added in 7.15.4 and replaces the old \fIcurl_unescape(3)\fP function.
.SH RETURN VALUE
A pointer to a null-terminated string or NULL if it failed.
.SH "SEE ALSO"
.BR curl_easy_escape "(3), " curl_free "(3)," RFC 3986