build with -Wall -Wextra -Werror and fix errors

mfshell/commands/auth.c

@@ -36,7 +36,6 @@ _get_passwd_from_user(void);
 int
 mfshell_cmd_auth(mfshell_t *mfshell, int argc, char **argv)
 {
-    int retval;
     char *username;
     char *password;
 

mfshell/commands/debug.c

@@ -30,6 +30,7 @@
 int
 mfshell_cmd_debug(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
     if (argc != 1) {
         fprintf(stderr, "Invalid number of arguments\n");
         return -1;

mfshell/commands/file.c

@@ -52,6 +52,9 @@ mfshell_cmd_file(mfshell_t *mfshell, int argc, char **argv)
     file = file_alloc();
 
     retval = mfconn_api_file_get_info(mfshell->mfconn,file,(char*)quickkey);
+    if (retval != 0) {
+        fprintf(stderr, "api call unsuccessful\n");
+    }
     mfconn_update_secret_key(mfshell->mfconn);
 
     quickkey = file_get_key(file);

mfshell/commands/get.c

@@ -80,9 +80,9 @@ mfshell_cmd_get(mfshell_t *mfshell, int argc, char **argv)
         getcwd(mfshell->local_working_dir,PATH_MAX);
     }
 
-    retval = file_download_direct(file, mfshell->local_working_dir);
+    bytes_read = file_download_direct(file, mfshell->local_working_dir);
 
-    if(retval != -1)
+    if(bytes_read != -1)
         printf("\r   Downloaded %zd bytes OK!\n\r",bytes_read);
     else
         printf("\r\n   Download FAILED!\n\r");

mfshell/commands/help.c

@@ -28,6 +28,12 @@
 int
 mfshell_cmd_help(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
+    if (argc != 1) {
+        fprintf(stderr, "Invalid number of arguments\n");
+        return -1;
+    }
+
     printf(
         "  arguments:\n\r"
         "           <optional>\n\r"
@@ -35,8 +41,8 @@ mfshell_cmd_help(mfshell_t *mfshell, int argc, char **argv)
 
     printf("\n\r");
 
-    int column1_width = 0;
-    int column2_width = 0;
+    unsigned int column1_width = 0;
+    unsigned int column2_width = 0;
 
     _cmd_t* curr_cmd;
     for (curr_cmd = mfshell->commands; curr_cmd->name != NULL; curr_cmd++) {

mfshell/commands/links.c

@@ -53,6 +53,9 @@ mfshell_cmd_links(mfshell_t *mfshell, int argc, char **argv)
     file = file_alloc();
 
     retval = mfconn_api_file_get_links(mfshell->mfconn,file,(char*)quickkey);
+    if (retval != 0) {
+        fprintf(stderr, "api call unsuccessful\n");
+    }
     mfconn_update_secret_key(mfshell->mfconn);
 
     share_link = file_get_share_link(file);

mfshell/commands/list.c

@@ -29,6 +29,7 @@
 int
 mfshell_cmd_list(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
     int         retval;
     const char  *folder_curr;
 

mfshell/commands/lpwd.c

@@ -29,6 +29,7 @@
 int
 mfshell_cmd_lpwd(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
     if(mfshell == NULL) return -1;
 
     if (argc != 1) {

mfshell/commands/pwd.c

@@ -29,6 +29,7 @@
 int
 mfshell_cmd_pwd(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
     const char  *folder_name;
     char        *folder_name_tmp = NULL;
 

mfshell/commands/whoami.c

@@ -29,6 +29,7 @@
 int
 mfshell_cmd_whoami(mfshell_t *mfshell, int argc, char **argv)
 {
+    (void)argv;
     int retval;
 
     if (argc != 1) {