X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=unix%2Fuxplink.c;h=8351a6ea7280528acbe8660a0db18e66237823c0;hb=48eafd66aa274c32fc8169a0d36619663905c210;hp=40b126615e31f3b3662a29ac8585ba2e4c100b84;hpb=b5423b51d468b76eb2b6cd19bb2c900b882e24f3;p=PuTTY.git

diff --git a/unix/uxplink.c b/unix/uxplink.c
index 40b12661..8351a6ea 100644
--- a/unix/uxplink.c
+++ b/unix/uxplink.c
@@ -581,6 +581,8 @@ static void usage(void)
     printf("  -N        don't start a shell/command (SSH-2 only)\n");
     printf("  -nc host:port\n");
     printf("            open tunnel in place of session (SSH-2 only)\n");
+    printf("  -shareexists\n");
+    printf("            test whether a connection-sharing upstream exists\n");
     exit(1);
 }
 
@@ -607,6 +609,7 @@ int main(int argc, char **argv)
     int errors;
     int use_subsystem = 0;
     int got_host = FALSE;
+    int just_test_share_exists = FALSE;
     unsigned long now;
     struct winsize size;
 
@@ -685,6 +688,8 @@ int main(int argc, char **argv)
                     --argc;
 		    provide_xrm_string(*++argv);
 		}
+	    } else if (!strcmp(p, "-shareexists")) {
+                just_test_share_exists = TRUE;
 	    } else {
 		fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 		errors = 1;
@@ -959,6 +964,19 @@ int main(int argc, char **argv)
 	!conf_get_str_nthstrkey(conf, CONF_portfwd, 0))
 	conf_set_int(conf, CONF_ssh_simple, TRUE);
 
+    if (just_test_share_exists) {
+        if (!back->test_for_upstream) {
+            fprintf(stderr, "Connection sharing not supported for connection "
+                    "type '%s'\n", back->name);
+            return 1;
+        }
+        if (back->test_for_upstream(conf_get_str(conf, CONF_host),
+                                    conf_get_int(conf, CONF_port), conf))
+            return 0;
+        else
+            return 1;
+    }
+
     /*
      * Start up the connection.
      */