diff --git a/adb/commandline.c b/adb/commandline.c
index 8781081..3ee54c7 100644
--- a/adb/commandline.c
+++ b/adb/commandline.c
@@ -112,6 +112,7 @@
         "  adb push <local> <remote>    - copy file/dir to device\n"
         "  adb pull <remote> [<local>]  - copy file/dir from device\n"
         "  adb sync [ <directory> ]     - copy host->device only if changed\n"
+        "                                 (-l means list but don't copy)\n"
         "                                 (see 'adb help all')\n"
         "  adb shell                    - run remote shell interactively\n"
         "  adb shell <command>          - run remote shell command\n"
@@ -1041,10 +1042,19 @@
 
     if(!strcmp(argv[0], "sync")) {
         char *srcarg, *android_srcpath, *data_srcpath;
+        int listonly = 0;
+
         int ret;
         if(argc < 2) {
             /* No local path was specified. */
             srcarg = NULL;
+        } else if (argc >= 2 && strcmp(argv[1], "-l") == 0) {
+            listonly = 1;
+            if (argc == 3) {
+                srcarg = argv[2];
+            } else {
+                srcarg = NULL;
+            }
         } else if(argc == 2) {
             /* A local path or "android"/"data" arg was specified. */
             srcarg = argv[1];
@@ -1055,9 +1065,9 @@
         if(ret != 0) return usage();
 
         if(android_srcpath != NULL)
-            ret = do_sync_sync(android_srcpath, "/system");
+            ret = do_sync_sync(android_srcpath, "/system", listonly);
         if(ret == 0 && data_srcpath != NULL)
-            ret = do_sync_sync(data_srcpath, "/data");
+            ret = do_sync_sync(data_srcpath, "/data", listonly);
 
         free(android_srcpath);
         free(data_srcpath);
diff --git a/adb/file_sync_client.c b/adb/file_sync_client.c
index 65d4941..da25ae8 100644
--- a/adb/file_sync_client.c
+++ b/adb/file_sync_client.c
@@ -670,7 +670,7 @@
 }
 
 
-static int copy_local_dir_remote(int fd, const char *lpath, const char *rpath, int checktimestamps)
+static int copy_local_dir_remote(int fd, const char *lpath, const char *rpath, int checktimestamps, int listonly)
 {
     copyinfo *filelist = 0;
     copyinfo *ci, *next;
@@ -718,8 +718,9 @@
     for(ci = filelist; ci != 0; ci = next) {
         next = ci->next;
         if(ci->flag == 0) {
-            fprintf(stderr,"push: %s -> %s\n", ci->src, ci->dst);
-            if(sync_send(fd, ci->src, ci->dst, ci->time, ci->mode, 0 /* no verify APK */)){
+            fprintf(stderr,"%spush: %s -> %s\n", listonly ? "would " : "", ci->src, ci->dst);
+            if(!listonly &&
+               sync_send(fd, ci->src, ci->dst, ci->time, ci->mode, 0 /* no verify APK */)){
                 return 1;
             }
             pushed++;
@@ -757,7 +758,7 @@
 
     if(S_ISDIR(st.st_mode)) {
         BEGIN();
-        if(copy_local_dir_remote(fd, lpath, rpath, 0)) {
+        if(copy_local_dir_remote(fd, lpath, rpath, 0, 0)) {
             return 1;
         } else {
             END();
@@ -1001,7 +1002,7 @@
     }
 }
 
-int do_sync_sync(const char *lpath, const char *rpath)
+int do_sync_sync(const char *lpath, const char *rpath, int listonly)
 {
     fprintf(stderr,"syncing %s...\n",rpath);
 
@@ -1012,7 +1013,7 @@
     }
 
     BEGIN();
-    if(copy_local_dir_remote(fd, lpath, rpath, 1)){
+    if(copy_local_dir_remote(fd, lpath, rpath, 1, listonly)){
         return 1;
     } else {
         END();
diff --git a/adb/file_sync_service.h b/adb/file_sync_service.h
index 4ee40ba..11ea06b 100644
--- a/adb/file_sync_service.h
+++ b/adb/file_sync_service.h
@@ -79,7 +79,7 @@
 void file_sync_service(int fd, void *cookie);
 int do_sync_ls(const char *path);
 int do_sync_push(const char *lpath, const char *rpath, int verifyApk);
-int do_sync_sync(const char *lpath, const char *rpath);
+int do_sync_sync(const char *lpath, const char *rpath, int listonly);
 int do_sync_pull(const char *rpath, const char *lpath);
 
 #define SYNC_DATA_MAX (64*1024)