More improvements to the minimal NSH when there is no file system and when print fieldwidths are suppressed

examples/nsh/nsh_main.c

@@ -174,7 +174,12 @@ int nsh_main(int argc, char *argv[])
    * is wrong.
    */
 
+#if CONFIG_NFILE_DESCRIPTORS > 0
   fprintf(stderr, "ERROR: nsh_consolemain() returned: %d\n", ret);
+#else
+  printf("ERROR: nsh_consolemain() returned: %d\n", ret);
+#endif
+
   exitval = 1;
 #endif
 

nshlib/nsh_console.c

@@ -198,6 +198,8 @@ static ssize_t nsh_consolewrite(FAR struct nsh_vtbl_s *vtbl, FAR const void *buf
     }
   return ret;
 #else
+  /* REVISIT: buffer may not be NUL-terminated */
+
   printf("%s", buffer);
   return nbytes;
 #endif
@@ -234,13 +236,30 @@ static int nsh_consoleoutput(FAR struct nsh_vtbl_s *vtbl, const char *fmt, ...)
 
   return ret;
 #else
-  char dest[64 * 16];
+  va_list ap;
+  char *str;
+  int ret;
+
+  /* Use avsprintf() to allocate a buffer and fill it with the formatted
+   * data
+   */
 
   va_start(ap, fmt);
-  vsprintf(dest, fmt, ap);
-  va_end(ap);
+  str = NULL;
+  (void)avsprintf(&str, fmt, ap);
 
-  return printf(dest);
+  /* Was a string allocated? */
+
+  if (str)
+    {
+      /* Yes.. Print then free the allocated string */
+
+      printf("%s", str);
+      free(str);
+    }
+
+  va_end(ap);
+  return 0;
 #endif
 }
 

nshlib/nsh_mmcmds.c

@@ -87,9 +87,15 @@ int cmd_free(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
   (void)mallinfo(&mem);
 #endif
 
+#ifdef CONFIG_NOPRINTF_FIELDWIDTH
+  nsh_output(vtbl, "\ttotal\tused\tfree\tlargest\n");
+  nsh_output(vtbl, "Mem:\t%d\t%d\t%d\t%d\n",
+             mem.arena, mem.uordblks, mem.fordblks, mem.mxordblk);
+#else
   nsh_output(vtbl, "             total       used       free    largest\n");
   nsh_output(vtbl, "Mem:   %11d%11d%11d%11d\n",
              mem.arena, mem.uordblks, mem.fordblks, mem.mxordblk);
+#endif
 
   return OK;
 }

nshlib/nsh_parse.c

@@ -513,7 +513,11 @@ static inline void help_cmdlist(FAR struct nsh_vtbl_s *vtbl)
       nsh_output(vtbl, "  ");
       for (j = 0, k = i; j < CMDS_PER_LINE && k < NUM_CMDS; j++, k += NUM_CMD_ROWS)
         {
+#ifdef CONFIG_NOPRINTF_FIELDWIDTH
+          nsh_output(vtbl, "%s\t", g_cmdmap[k].cmd);
+#else
           nsh_output(vtbl, "%-12s", g_cmdmap[k].cmd);
+#endif
         }
 
       nsh_output(vtbl, "\n");