alt-svc: the curl command line bits

docs/cmdline-opts/Makefile.inc

@@ -2,6 +2,7 @@
 
 DPAGES =					\
   abstract-unix-socket.d			\
+  alt-svc.d                                     \
   anyauth.d					\
   append.d basic.d				\
   cacert.d capath.d				\

docs/cmdline-opts/alt-svc.d

@@ -0,0 +1,17 @@
+Long: alt-svc
+Arg: <file name>
+Protocols: HTTPS
+Help: Enable alt-svc with this cache file
+Added: 7.64.1
+---
+WARNING: this option is experiemental. Do not use in production.
+
+This option enables the alt-svc parser in curl. If the file name points to an
+existing alt-svc cache file, that will be used. After a completed transfer,
+the cache will be saved to the file name again if it has been modified.
+
+Specifiy a "" file name (zero length) to avoid loading/saving and make curl
+just handle the cache in memory.
+
+If this option is used several times, curl will load contents from all the
+files but the the last one will be used for saving.

src/tool_cfgable.c

@@ -53,6 +53,7 @@ static void free_config_fields(struct OperationConfig *config)
   Curl_safefree(config->random_file);
   Curl_safefree(config->egd_file);
   Curl_safefree(config->useragent);
+  Curl_safefree(config->altsvc);
   Curl_safefree(config->cookie);
   Curl_safefree(config->cookiejar);
   Curl_safefree(config->cookiefile);

src/tool_cfgable.h

@@ -46,6 +46,7 @@ struct OperationConfig {
   char *cookie;             /* single line with specified cookies */
   char *cookiejar;          /* write to this file */
   char *cookiefile;         /* read from this file */
+  char *altsvc;             /* alt-svc cache file name */
   bool cookiesession;       /* new session? */
   bool encoding;            /* Accept-Encoding please */
   bool tr_encoding;         /* Transfer-Encoding please */

src/tool_getparam.c

@@ -214,6 +214,7 @@ static const struct LongShort aliases[]= {
   {"a",  "append",                   ARG_BOOL},
   {"A",  "user-agent",               ARG_STRING},
   {"b",  "cookie",                   ARG_STRING},
+  {"ba", "alt-svc",                  ARG_STRING},
   {"B",  "use-ascii",                ARG_BOOL},
   {"c",  "cookie-jar",               ARG_STRING},
   {"C",  "continue-at",              ARG_STRING},
@@ -1244,7 +1245,12 @@ ParameterError getparameter(const char *flag, /* f or -long-flag */
       /* This specifies the User-Agent name */
       GetStr(&config->useragent, nextarg);
       break;
-    case 'b': /* cookie string coming up: */
+    case 'b':
+      switch(subletter) {
+      case 'a': /* --alt-svc */
+        GetStr(&config->altsvc, nextarg);
+        break;
+      default:  /* --cookie string coming up: */
         if(nextarg[0] == '@') {
           nextarg++;
         }
@@ -1255,6 +1261,7 @@ ParameterError getparameter(const char *flag, /* f or -long-flag */
         }
         /* We have a cookie file to read from! */
         GetStr(&config->cookiefile, nextarg);
+      }
       break;
     case 'B':
       /* use ASCII/text when transferring */

src/tool_help.c

@@ -48,6 +48,8 @@ struct helptxt {
 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",

src/tool_operate.c

@@ -1538,6 +1538,12 @@ static CURLcode operate_do(struct GlobalConfig *global,
         if(config->disallow_username_in_url)
           my_setopt(curl, CURLOPT_DISALLOW_USERNAME_IN_URL, 1L);
 
+#ifdef USE_ALTSVC
+        /* only if explicitly enabled in configure */
+        if(config->altsvc)
+          my_setopt_str(curl, CURLOPT_ALTSVC, config->altsvc);
+#endif
+
         /* initialize retry vars for loop below */
         retry_sleep_default = (config->retry_delay) ?
           config->retry_delay*1000L : RETRY_SLEEP_DEFAULT; /* ms */