--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/src/tool_help.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,634 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, 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.haxx.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.
+ *
+ ***************************************************************************/
+#include "tool_setup.h"
+#if defined(HAVE_STRCASECMP) && defined(HAVE_STRINGS_H)
+#include <strings.h>
+#endif
+
+#include "tool_panykey.h"
+#include "tool_help.h"
+#include "tool_libinfo.h"
+#include "tool_version.h"
+
+#include "memdebug.h" /* keep this as LAST include */
+
+#ifdef MSDOS
+#  define USE_WATT32
+#endif
+
+/*
+ * The help output is generated with the following command
+ ---------------------------------------------------------
+
+  cd $srcroot/docs/cmdline-opts
+  ./gen.pl listhelp
+ */
+
+struct helptxt {
+  const char *opt;
+  const char *desc;
+};
+
+static const struct helptxt helptext[] = {
+  {"    --abstract-unix-socket <path>",
+   "Connect via abstract Unix domain socket"},
+  {"    --alt-svc <file name>",
+   "Enable alt-svc with this cache file"},
+  {"    --anyauth",
+   "Pick any authentication method"},
+  {"-a, --append",
+   "Append to target file when uploading"},
+  {"    --basic",
+   "Use HTTP Basic Authentication"},
+  {"    --cacert <file>",
+   "CA certificate to verify peer against"},
+  {"    --capath <dir>",
+   "CA directory to verify peer against"},
+  {"-E, --cert <certificate[:password]>",
+   "Client certificate file and password"},
+  {"    --cert-status",
+   "Verify the status of the server certificate"},
+  {"    --cert-type <type>",
+   "Certificate file type (DER/PEM/ENG)"},
+  {"    --ciphers <list of ciphers>",
+   "SSL ciphers to use"},
+  {"    --compressed",
+   "Request compressed response"},
+  {"    --compressed-ssh",
+   "Enable SSH compression"},
+  {"-K, --config <file>",
+   "Read config from a file"},
+  {"    --connect-timeout <seconds>",
+   "Maximum time allowed for connection"},
+  {"    --connect-to <HOST1:PORT1:HOST2:PORT2>",
+   "Connect to host"},
+  {"-C, --continue-at <offset>",
+   "Resumed transfer offset"},
+  {"-b, --cookie <data|filename>",
+   "Send cookies from string/file"},
+  {"-c, --cookie-jar <filename>",
+   "Write cookies to <filename> after operation"},
+  {"    --create-dirs",
+   "Create necessary local directory hierarchy"},
+  {"    --crlf",
+   "Convert LF to CRLF in upload"},
+  {"    --crlfile <file>",
+   "Get a CRL list in PEM format from the given file"},
+  {"-d, --data <data>",
+   "HTTP POST data"},
+  {"    --data-ascii <data>",
+   "HTTP POST ASCII data"},
+  {"    --data-binary <data>",
+   "HTTP POST binary data"},
+  {"    --data-raw <data>",
+   "HTTP POST data, '@' allowed"},
+  {"    --data-urlencode <data>",
+   "HTTP POST data url encoded"},
+  {"    --delegation <LEVEL>",
+   "GSS-API delegation permission"},
+  {"    --digest",
+   "Use HTTP Digest Authentication"},
+  {"-q, --disable",
+   "Disable .curlrc"},
+  {"    --disable-eprt",
+   "Inhibit using EPRT or LPRT"},
+  {"    --disable-epsv",
+   "Inhibit using EPSV"},
+  {"    --disallow-username-in-url",
+   "Disallow username in url"},
+  {"    --dns-interface <interface>",
+   "Interface to use for DNS requests"},
+  {"    --dns-ipv4-addr <address>",
+   "IPv4 address to use for DNS requests"},
+  {"    --dns-ipv6-addr <address>",
+   "IPv6 address to use for DNS requests"},
+  {"    --dns-servers <addresses>",
+   "DNS server addrs to use"},
+  {"    --doh-url <URL>",
+   "Resolve host names over DOH"},
+  {"-D, --dump-header <filename>",
+   "Write the received headers to <filename>"},
+  {"    --egd-file <file>",
+   "EGD socket path for random data"},
+  {"    --engine <name>",
+   "Crypto engine to use"},
+  {"    --expect100-timeout <seconds>",
+   "How long to wait for 100-continue"},
+  {"-f, --fail",
+   "Fail silently (no output at all) on HTTP errors"},
+  {"    --fail-early",
+   "Fail on first transfer error, do not continue"},
+  {"    --false-start",
+   "Enable TLS False Start"},
+  {"-F, --form <name=content>",
+   "Specify multipart MIME data"},
+  {"    --form-string <name=string>",
+   "Specify multipart MIME data"},
+  {"    --ftp-account <data>",
+   "Account data string"},
+  {"    --ftp-alternative-to-user <command>",
+   "String to replace USER [name]"},
+  {"    --ftp-create-dirs",
+   "Create the remote dirs if not present"},
+  {"    --ftp-method <method>",
+   "Control CWD usage"},
+  {"    --ftp-pasv",
+   "Use PASV/EPSV instead of PORT"},
+  {"-P, --ftp-port <address>",
+   "Use PORT instead of PASV"},
+  {"    --ftp-pret",
+   "Send PRET before PASV"},
+  {"    --ftp-skip-pasv-ip",
+   "Skip the IP address for PASV"},
+  {"    --ftp-ssl-ccc",
+   "Send CCC after authenticating"},
+  {"    --ftp-ssl-ccc-mode <active/passive>",
+   "Set CCC mode"},
+  {"    --ftp-ssl-control",
+   "Require SSL/TLS for FTP login, clear for transfer"},
+  {"-G, --get",
+   "Put the post data in the URL and use GET"},
+  {"-g, --globoff",
+   "Disable URL sequences and ranges using {} and []"},
+  {"    --happy-eyeballs-timeout-ms <milliseconds>",
+   "How long to wait in milliseconds for IPv6 before trying IPv4"},
+  {"    --haproxy-protocol",
+   "Send HAProxy PROXY protocol v1 header"},
+  {"-I, --head",
+   "Show document info only"},
+  {"-H, --header <header/@file>",
+   "Pass custom header(s) to server"},
+  {"-h, --help",
+   "This help text"},
+  {"    --hostpubmd5 <md5>",
+   "Acceptable MD5 hash of the host public key"},
+  {"    --http0.9",
+   "Allow HTTP 0.9 responses"},
+  {"-0, --http1.0",
+   "Use HTTP 1.0"},
+  {"    --http1.1",
+   "Use HTTP 1.1"},
+  {"    --http2",
+   "Use HTTP 2"},
+  {"    --http2-prior-knowledge",
+   "Use HTTP 2 without HTTP/1.1 Upgrade"},
+  {"    --http3",
+   "Use HTTP v3"},
+  {"    --ignore-content-length",
+   "Ignore the size of the remote resource"},
+  {"-i, --include",
+   "Include protocol response headers in the output"},
+  {"-k, --insecure",
+   "Allow insecure server connections when using SSL"},
+  {"    --interface <name>",
+   "Use network INTERFACE (or address)"},
+  {"-4, --ipv4",
+   "Resolve names to IPv4 addresses"},
+  {"-6, --ipv6",
+   "Resolve names to IPv6 addresses"},
+  {"-j, --junk-session-cookies",
+   "Ignore session cookies read from file"},
+  {"    --keepalive-time <seconds>",
+   "Interval time for keepalive probes"},
+  {"    --key <key>",
+   "Private key file name"},
+  {"    --key-type <type>",
+   "Private key file type (DER/PEM/ENG)"},
+  {"    --krb <level>",
+   "Enable Kerberos with security <level>"},
+  {"    --libcurl <file>",
+   "Dump libcurl equivalent code of this command line"},
+  {"    --limit-rate <speed>",
+   "Limit transfer speed to RATE"},
+  {"-l, --list-only",
+   "List only mode"},
+  {"    --local-port <num/range>",
+   "Force use of RANGE for local port numbers"},
+  {"-L, --location",
+   "Follow redirects"},
+  {"    --location-trusted",
+   "Like --location, and send auth to other hosts"},
+  {"    --login-options <options>",
+   "Server login options"},
+  {"    --mail-auth <address>",
+   "Originator address of the original email"},
+  {"    --mail-from <address>",
+   "Mail from this address"},
+  {"    --mail-rcpt <address>",
+   "Mail to this address"},
+  {"-M, --manual",
+   "Display the full manual"},
+  {"    --max-filesize <bytes>",
+   "Maximum file size to download"},
+  {"    --max-redirs <num>",
+   "Maximum number of redirects allowed"},
+  {"-m, --max-time <seconds>",
+   "Maximum time allowed for the transfer"},
+  {"    --metalink",
+   "Process given URLs as metalink XML file"},
+  {"    --negotiate",
+   "Use HTTP Negotiate (SPNEGO) authentication"},
+  {"-n, --netrc",
+   "Must read .netrc for user name and password"},
+  {"    --netrc-file <filename>",
+   "Specify FILE for netrc"},
+  {"    --netrc-optional",
+   "Use either .netrc or URL"},
+  {"-:, --next",
+   "Make next URL use its separate set of options"},
+  {"    --no-alpn",
+   "Disable the ALPN TLS extension"},
+  {"-N, --no-buffer",
+   "Disable buffering of the output stream"},
+  {"    --no-keepalive",
+   "Disable TCP keepalive on the connection"},
+  {"    --no-npn",
+   "Disable the NPN TLS extension"},
+  {"    --no-sessionid",
+   "Disable SSL session-ID reusing"},
+  {"    --noproxy <no-proxy-list>",
+   "List of hosts which do not use proxy"},
+  {"    --ntlm",
+   "Use HTTP NTLM authentication"},
+  {"    --ntlm-wb",
+   "Use HTTP NTLM authentication with winbind"},
+  {"    --oauth2-bearer <token>",
+   "OAuth 2 Bearer Token"},
+  {"-o, --output <file>",
+   "Write to file instead of stdout"},
+  {"-Z, --parallel",
+   "Perform transfers in parallel"},
+  {"    --parallel-max",
+   "Maximum concurrency for parallel transfers"},
+  {"    --pass <phrase>",
+   "Pass phrase for the private key"},
+  {"    --path-as-is",
+   "Do not squash .. sequences in URL path"},
+  {"    --pinnedpubkey <hashes>",
+   "FILE/HASHES Public key to verify peer against"},
+  {"    --post301",
+   "Do not switch to GET after following a 301"},
+  {"    --post302",
+   "Do not switch to GET after following a 302"},
+  {"    --post303",
+   "Do not switch to GET after following a 303"},
+  {"    --preproxy [protocol://]host[:port]",
+   "Use this proxy first"},
+  {"-#, --progress-bar",
+   "Display transfer progress as a bar"},
+  {"    --proto <protocols>",
+   "Enable/disable PROTOCOLS"},
+  {"    --proto-default <protocol>",
+   "Use PROTOCOL for any URL missing a scheme"},
+  {"    --proto-redir <protocols>",
+   "Enable/disable PROTOCOLS on redirect"},
+  {"-x, --proxy [protocol://]host[:port]",
+   "Use this proxy"},
+  {"    --proxy-anyauth",
+   "Pick any proxy authentication method"},
+  {"    --proxy-basic",
+   "Use Basic authentication on the proxy"},
+  {"    --proxy-cacert <file>",
+   "CA certificate to verify peer against for proxy"},
+  {"    --proxy-capath <dir>",
+   "CA directory to verify peer against for proxy"},
+  {"    --proxy-cert <cert[:passwd]>",
+   "Set client certificate for proxy"},
+  {"    --proxy-cert-type <type>",
+   "Client certificate type for HTTPS proxy"},
+  {"    --proxy-ciphers <list>",
+   "SSL ciphers to use for proxy"},
+  {"    --proxy-crlfile <file>",
+   "Set a CRL list for proxy"},
+  {"    --proxy-digest",
+   "Use Digest authentication on the proxy"},
+  {"    --proxy-header <header/@file>",
+   "Pass custom header(s) to proxy"},
+  {"    --proxy-insecure",
+   "Do HTTPS proxy connections without verifying the proxy"},
+  {"    --proxy-key <key>",
+   "Private key for HTTPS proxy"},
+  {"    --proxy-key-type <type>",
+   "Private key file type for proxy"},
+  {"    --proxy-negotiate",
+   "Use HTTP Negotiate (SPNEGO) authentication on the proxy"},
+  {"    --proxy-ntlm",
+   "Use NTLM authentication on the proxy"},
+  {"    --proxy-pass <phrase>",
+   "Pass phrase for the private key for HTTPS proxy"},
+  {"    --proxy-pinnedpubkey <hashes>",
+   "FILE/HASHES public key to verify proxy with"},
+  {"    --proxy-service-name <name>",
+   "SPNEGO proxy service name"},
+  {"    --proxy-ssl-allow-beast",
+   "Allow security flaw for interop for HTTPS proxy"},
+  {"    --proxy-tls13-ciphers <list>",
+   "TLS 1.3 ciphersuites for proxy (OpenSSL)"},
+  {"    --proxy-tlsauthtype <type>",
+   "TLS authentication type for HTTPS proxy"},
+  {"    --proxy-tlspassword <string>",
+   "TLS password for HTTPS proxy"},
+  {"    --proxy-tlsuser <name>",
+   "TLS username for HTTPS proxy"},
+  {"    --proxy-tlsv1",
+   "Use TLSv1 for HTTPS proxy"},
+  {"-U, --proxy-user <user:password>",
+   "Proxy user and password"},
+  {"    --proxy1.0 <host[:port]>",
+   "Use HTTP/1.0 proxy on given port"},
+  {"-p, --proxytunnel",
+   "Operate through an HTTP proxy tunnel (using CONNECT)"},
+  {"    --pubkey <key>",
+   "SSH Public key file name"},
+  {"-Q, --quote",
+   "Send command(s) to server before transfer"},
+  {"    --random-file <file>",
+   "File for reading random data from"},
+  {"-r, --range <range>",
+   "Retrieve only the bytes within RANGE"},
+  {"    --raw",
+   "Do HTTP \"raw\"; no transfer decoding"},
+  {"-e, --referer <URL>",
+   "Referrer URL"},
+  {"-J, --remote-header-name",
+   "Use the header-provided filename"},
+  {"-O, --remote-name",
+   "Write output to a file named as the remote file"},
+  {"    --remote-name-all",
+   "Use the remote file name for all URLs"},
+  {"-R, --remote-time",
+   "Set the remote file's time on the local output"},
+  {"-X, --request <command>",
+   "Specify request command to use"},
+  {"    --request-target",
+   "Specify the target for this request"},
+  {"    --resolve <host:port:address[,address]...>",
+   "Resolve the host+port to this address"},
+  {"    --retry <num>",
+   "Retry request if transient problems occur"},
+  {"    --retry-connrefused",
+   "Retry on connection refused (use with --retry)"},
+  {"    --retry-delay <seconds>",
+   "Wait time between retries"},
+  {"    --retry-max-time <seconds>",
+   "Retry only within this period"},
+  {"    --sasl-authzid <identity> ",
+   "Use this identity to act as during SASL PLAIN authentication"},
+  {"    --sasl-ir",
+   "Enable initial response in SASL authentication"},
+  {"    --service-name <name>",
+   "SPNEGO service name"},
+  {"-S, --show-error",
+   "Show error even when -s is used"},
+  {"-s, --silent",
+   "Silent mode"},
+  {"    --socks4 <host[:port]>",
+   "SOCKS4 proxy on given host + port"},
+  {"    --socks4a <host[:port]>",
+   "SOCKS4a proxy on given host + port"},
+  {"    --socks5 <host[:port]>",
+   "SOCKS5 proxy on given host + port"},
+  {"    --socks5-basic",
+   "Enable username/password auth for SOCKS5 proxies"},
+  {"    --socks5-gssapi",
+   "Enable GSS-API auth for SOCKS5 proxies"},
+  {"    --socks5-gssapi-nec",
+   "Compatibility with NEC SOCKS5 server"},
+  {"    --socks5-gssapi-service <name>",
+   "SOCKS5 proxy service name for GSS-API"},
+  {"    --socks5-hostname <host[:port]>",
+   "SOCKS5 proxy, pass host name to proxy"},
+  {"-Y, --speed-limit <speed>",
+   "Stop transfers slower than this"},
+  {"-y, --speed-time <seconds>",
+   "Trigger 'speed-limit' abort after this time"},
+  {"    --ssl",
+   "Try SSL/TLS"},
+  {"    --ssl-allow-beast",
+   "Allow security flaw to improve interop"},
+  {"    --ssl-no-revoke",
+   "Disable cert revocation checks (Schannel)"},
+  {"    --ssl-reqd",
+   "Require SSL/TLS"},
+  {"-2, --sslv2",
+   "Use SSLv2"},
+  {"-3, --sslv3",
+   "Use SSLv3"},
+  {"    --stderr",
+   "Where to redirect stderr"},
+  {"    --styled-output",
+   "Enable styled output for HTTP headers"},
+  {"    --suppress-connect-headers",
+   "Suppress proxy CONNECT response headers"},
+  {"    --tcp-fastopen",
+   "Use TCP Fast Open"},
+  {"    --tcp-nodelay",
+   "Use the TCP_NODELAY option"},
+  {"-t, --telnet-option <opt=val>",
+   "Set telnet option"},
+  {"    --tftp-blksize <value>",
+   "Set TFTP BLKSIZE option"},
+  {"    --tftp-no-options",
+   "Do not send any TFTP options"},
+  {"-z, --time-cond <time>",
+   "Transfer based on a time condition"},
+  {"    --tls-max <VERSION>",
+   "Set maximum allowed TLS version"},
+  {"    --tls13-ciphers <list>",
+   "TLS 1.3 ciphersuites (OpenSSL)"},
+  {"    --tlsauthtype <type>",
+   "TLS authentication type"},
+  {"    --tlspassword",
+   "TLS password"},
+  {"    --tlsuser <name>",
+   "TLS user name"},
+  {"-1, --tlsv1",
+   "Use TLSv1.0 or greater"},
+  {"    --tlsv1.0",
+   "Use TLSv1.0 or greater"},
+  {"    --tlsv1.1",
+   "Use TLSv1.1 or greater"},
+  {"    --tlsv1.2",
+   "Use TLSv1.2 or greater"},
+  {"    --tlsv1.3",
+   "Use TLSv1.3 or greater"},
+  {"    --tr-encoding",
+   "Request compressed transfer encoding"},
+  {"    --trace <file>",
+   "Write a debug trace to FILE"},
+  {"    --trace-ascii <file>",
+   "Like --trace, but without hex output"},
+  {"    --trace-time",
+   "Add time stamps to trace/verbose output"},
+  {"    --unix-socket <path>",
+   "Connect through this Unix domain socket"},
+  {"-T, --upload-file <file>",
+   "Transfer local FILE to destination"},
+  {"    --url <url>",
+   "URL to work with"},
+  {"-B, --use-ascii",
+   "Use ASCII/text transfer"},
+  {"-u, --user <user:password>",
+   "Server user and password"},
+  {"-A, --user-agent <name>",
+   "Send User-Agent <name> to server"},
+  {"-v, --verbose",
+   "Make the operation more talkative"},
+  {"-V, --version",
+   "Show version number and quit"},
+  {"-w, --write-out <format>",
+   "Use output FORMAT after completion"},
+  {"    --xattr",
+   "Store metadata in extended file attributes"},
+  { NULL, NULL }
+};
+
+#ifdef NETWARE
+#  define PRINT_LINES_PAUSE 23
+#endif
+
+#ifdef __SYMBIAN32__
+#  define PRINT_LINES_PAUSE 16
+#endif
+
+struct feat {
+  const char *name;
+  int bitmask;
+};
+
+static const struct feat feats[] = {
+  {"AsynchDNS",      CURL_VERSION_ASYNCHDNS},
+  {"Debug",          CURL_VERSION_DEBUG},
+  {"TrackMemory",    CURL_VERSION_CURLDEBUG},
+  {"IDN",            CURL_VERSION_IDN},
+  {"IPv6",           CURL_VERSION_IPV6},
+  {"Largefile",      CURL_VERSION_LARGEFILE},
+  {"SSPI",           CURL_VERSION_SSPI},
+  {"GSS-API",        CURL_VERSION_GSSAPI},
+  {"Kerberos",       CURL_VERSION_KERBEROS5},
+  {"SPNEGO",         CURL_VERSION_SPNEGO},
+  {"NTLM",           CURL_VERSION_NTLM},
+  {"NTLM_WB",        CURL_VERSION_NTLM_WB},
+  {"SSL",            CURL_VERSION_SSL},
+  {"libz",           CURL_VERSION_LIBZ},
+  {"brotli",         CURL_VERSION_BROTLI},
+  {"CharConv",       CURL_VERSION_CONV},
+  {"TLS-SRP",        CURL_VERSION_TLSAUTH_SRP},
+  {"HTTP2",          CURL_VERSION_HTTP2},
+  {"HTTP3",          CURL_VERSION_HTTP3},
+  {"UnixSockets",    CURL_VERSION_UNIX_SOCKETS},
+  {"HTTPS-proxy",    CURL_VERSION_HTTPS_PROXY},
+  {"MultiSSL",       CURL_VERSION_MULTI_SSL},
+  {"PSL",            CURL_VERSION_PSL},
+  {"alt-svc",        CURL_VERSION_ALTSVC},
+};
+
+void tool_help(void)
+{
+  int i;
+  puts("Usage: curl [options...] <url>");
+  for(i = 0; helptext[i].opt; i++) {
+    printf(" %-19s %s\n", helptext[i].opt, helptext[i].desc);
+#ifdef PRINT_LINES_PAUSE
+    if(i && ((i % PRINT_LINES_PAUSE) == 0))
+      tool_pressanykey();
+#endif
+  }
+}
+
+static int
+featcomp(const void *p1, const void *p2)
+{
+  /* The arguments to this function are "pointers to pointers to char", but
+     the comparison arguments are "pointers to char", hence the following cast
+     plus dereference */
+#ifdef HAVE_STRCASECMP
+  return strcasecmp(* (char * const *) p1, * (char * const *) p2);
+#elif defined(HAVE_STRCMPI)
+  return strcmpi(* (char * const *) p1, * (char * const *) p2);
+#else
+  return strcmp(* (char * const *) p1, * (char * const *) p2);
+#endif
+}
+
+void tool_version_info(void)
+{
+  const char *const *proto;
+
+  printf(CURL_ID "%s\n", curl_version());
+#ifdef CURL_PATCHSTAMP
+  printf("Release-Date: %s, security patched: %s\n",
+         LIBCURL_TIMESTAMP, CURL_PATCHSTAMP);
+#else
+  printf("Release-Date: %s\n", LIBCURL_TIMESTAMP);
+#endif
+  if(curlinfo->protocols) {
+    printf("Protocols: ");
+    for(proto = curlinfo->protocols; *proto; ++proto) {
+      printf("%s ", *proto);
+    }
+    puts(""); /* newline */
+  }
+  if(curlinfo->features) {
+    char *featp[ sizeof(feats) / sizeof(feats[0]) + 1];
+    size_t numfeat = 0;
+    unsigned int i;
+    printf("Features:");
+    for(i = 0; i < sizeof(feats)/sizeof(feats[0]); i++) {
+      if(curlinfo->features & feats[i].bitmask)
+        featp[numfeat++] = (char *)feats[i].name;
+    }
+#ifdef USE_METALINK
+    featp[numfeat++] = (char *)"Metalink";
+#endif
+    qsort(&featp[0], numfeat, sizeof(char *), featcomp);
+    for(i = 0; i< numfeat; i++)
+      printf(" %s", featp[i]);
+    puts(""); /* newline */
+  }
+  if(strcmp(CURL_VERSION, curlinfo->version)) {
+    printf("WARNING: curl and libcurl versions do not match. "
+           "Functionality may be affected.\n");
+  }
+}
+
+void tool_list_engines(void)
+{
+  CURL *curl = curl_easy_init();
+  struct curl_slist *engines = NULL;
+
+  /* Get the list of engines */
+  curl_easy_getinfo(curl, CURLINFO_SSL_ENGINES, &engines);
+
+  puts("Build-time engines:");
+  if(engines) {
+    for(; engines; engines = engines->next)
+      printf("  %s\n", engines->data);
+  }
+  else {
+    puts("  <none>");
+  }
+
+  /* Cleanup the list of engines */
+  curl_slist_free_all(engines);
+  curl_easy_cleanup(curl);
+}