diff --git a/examples/sotest/lib/modprint/modprint.c b/examples/sotest/lib/modprint/modprint.c
index ea14702a7..f326c5cfe 100644
--- a/examples/sotest/lib/modprint/modprint.c
+++ b/examples/sotest/lib/modprint/modprint.c
@@ -36,7 +36,7 @@
  * Private Function Prototypes
  ****************************************************************************/
 
-static void modprint(FAR const char *fmt, ...);
+static void modprint(FAR const char *fmt, ...) printflike(1, 2);
 
 /****************************************************************************
  * Private Data
diff --git a/examples/sotest/lib/sotest/sotest.c b/examples/sotest/lib/sotest/sotest.c
index 549c15931..cfca240d2 100644
--- a/examples/sotest/lib/sotest/sotest.c
+++ b/examples/sotest/lib/sotest/sotest.c
@@ -37,7 +37,7 @@
  ****************************************************************************/
 
 #if CONFIG_MODLIB_MAXDEPEND > 0
-void modprint(FAR const char *fmt, ...);
+void modprint(FAR const char *fmt, ...) printflike(1, 2);
 #endif
 
 /****************************************************************************
diff --git a/include/graphics/curses.h b/include/graphics/curses.h
index acba716bd..3c9b79518 100644
--- a/include/graphics/curses.h
+++ b/include/graphics/curses.h
@@ -89,8 +89,7 @@
 #define MOUSE_X_POS             (Mouse_status.x)
 #define MOUSE_Y_POS             (Mouse_status.y)
 
-/*
- * Bits associated with the .changes field:
+/* Bits associated with the .changes field:
  *   3         2         1         0
  * 210987654321098765432109876543210
  *                                 1 <- button 1 has changed
@@ -139,8 +138,9 @@
 #define BUTTON3_MOVED           0x00004000L /* PDCurses */
 
 /* For the ncurses-compatible functions only, BUTTON4_PRESSED and
-   BUTTON5_PRESSED are returned for mouse scroll wheel up and down;
-   otherwise PDCurses doesn't support buttons 4 and 5 */
+ * BUTTON5_PRESSED are returned for mouse scroll wheel up and down;
+ * otherwise PDCurses doesn't support buttons 4 and 5
+ */
 
 #define BUTTON4_RELEASED        0x00008000L
 #define BUTTON4_PRESSED         0x00010000L
@@ -200,9 +200,9 @@
  *
  * long form:
  *
- * ----------------------------------------------------------------------------
- * |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|15|14|13|12|..| 3| 2| 1| 0|
- * ----------------------------------------------------------------------------
+ * -------------------------------------------------------------------------
+ * |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|15|14|13|..| 3| 2| 1| 0|
+ * -------------------------------------------------------------------------
  *       color number      |     modifiers         |      character eg 'a'
  *
  * The available non-color attributes are bold, underline, invisible,
@@ -345,8 +345,7 @@
 #define ACS_LANTERN   ACS_PICK('i', '*')
 #define ACS_BLOCK     ACS_PICK('0', '#')
 
-/* That goes double for these -- undocumented SysV symbols. Don't use
-   them. */
+/* That goes double for these -- undocumented SysV symbols. Don't use them. */
 
 #define ACS_S3        ACS_PICK('p', '-')
 #define ACS_S7        ACS_PICK('r', '-')
@@ -799,9 +798,12 @@ typedef unsigned long mmask_t;
 typedef struct
 {
   short id;             /* unused, always 0 */
-  int x, y, z;          /* x, y same as MOUSE_STATUS; z unused */
+  int x;                /* x, y same as MOUSE_STATUS; z unused */
+  int y;
+  int z;
   mmask_t bstate;       /* equivalent to changes + button[], but
-                         * in the same format as used for mousemask() */
+                         * in the same format as used for mousemask()
+                         */
 } MEVENT;
 
 /* PDCurses Structure Definitions */
@@ -830,7 +832,8 @@ typedef struct _win     /* definition of a window */
   int   _tmarg;         /* top of scrolling region */
   int   _bmarg;         /* bottom of scrolling region */
   int   _delayms;       /* milliseconds of delay for getch() */
-  int   _parx, _pary;   /* coords relative to parent (0,0) */
+  int   _parx;          /* coords relative to parent (0,0) */
+  int   _pary;
   struct _win *_parent; /* subwin's pointer to parent win */
 } WINDOW;
 
@@ -858,6 +861,7 @@ typedef struct
   int   orig_cursor;    /* original cursor size */
   int   lines;          /* new value for LINES */
   int   cols;           /* new value for COLS */
+
   unsigned long _trap_mbe;       /* trap these mouse button events */
   unsigned long _map_mbe_to_key; /* map mouse buttons to slk */
   int   mouse_wait;              /* time to wait (in ms) for a
@@ -942,9 +946,9 @@ struct pdc_context_s
   short         COLOR_PAIRS;
   short         TABSIZE;
   short         first_col;
-  short         c_pindex;        /* putter index */
-  short         c_gindex;        /* getter index */
-  short         c_ungind;        /* ungetch() push index */
+  short         c_pindex;            /* putter index */
+  short         c_gindex;            /* getter index */
+  short         c_ungind;            /* ungetch() push index */
   short         c_ungch[NUNGETCH];   /* array of ungotten chars */
   short         c_buffer[_INBUFSIZ]; /* character buffer */
   RIPPEDOFFLINE linesripped[5];
@@ -1026,8 +1030,8 @@ void                       PDC_ctx_free(void);
 #define graphic_screen     ctx->graphic_screen
 #endif
 
-void* pdc_alloc_panel_ctx(void);
-void* pdc_alloc_term_ctx(void);
+void *pdc_alloc_panel_ctx(void);
+void *pdc_alloc_term_ctx(void);
 
 #else
 
@@ -1072,7 +1076,8 @@ int     baudrate(void);
 int     beep(void);
 int     bkgd(chtype);
 void    bkgdset(chtype);
-int     border(chtype, chtype, chtype, chtype, chtype, chtype, chtype, chtype);
+int     border(chtype, chtype, chtype, chtype,
+               chtype, chtype, chtype, chtype);
 int     box(WINDOW *, chtype, chtype);
 bool    can_change_color(void);
 int     cbreak(void);
@@ -1160,8 +1165,8 @@ int     mvinsch(int, int, chtype);
 int     mvinsnstr(int, int, const char *, int);
 int     mvinsstr(int, int, const char *);
 int     mvinstr(int, int, char *);
-int     mvprintw(int, int, const char *, ...);
-int     mvscanw(int, int, const char *, ...);
+int     mvprintw(int, int, const char *, ...) printflike(3, 4);
+int     mvscanw(int, int, const char *, ...) scanflike(3, 4);
 int     mvvline(int, int, chtype, int);
 int     mvwaddchnstr(WINDOW *, int, int, const chtype *, int);
 int     mvwaddchstr(WINDOW *, int, int, const chtype *);
@@ -1183,8 +1188,8 @@ int     mvwinsnstr(WINDOW *, int, int, const char *, int);
 int     mvwinsstr(WINDOW *, int, int, const char *);
 int     mvwinstr(WINDOW *, int, int, char *);
 int     mvwin(WINDOW *, int, int);
-int     mvwprintw(WINDOW *, int, int, const char *, ...);
-int     mvwscanw(WINDOW *, int, int, const char *, ...);
+int     mvwprintw(WINDOW *, int, int, const char *, ...) printflike(4, 5);
+int     mvwscanw(WINDOW *, int, int, const char *, ...) scanflike(4, 5);
 int     mvwvline(WINDOW *, int, int, chtype, int);
 int     napms(int);
 WINDOW *newpad(int, int);
@@ -1204,7 +1209,7 @@ int     pair_content(short, short *, short *);
 int     pechochar(WINDOW *, chtype);
 int     pnoutrefresh(WINDOW *, int, int, int, int, int, int);
 int     prefresh(WINDOW *, int, int, int, int, int, int);
-int     printw(const char *, ...);
+int     printw(const char *, ...) printflike(1, 2);
 int     putwin(WINDOW *, FILE *);
 void    qiflush(void);
 int     raw(void);
@@ -1215,7 +1220,7 @@ int     reset_shell_mode(void);
 int     resetty(void);
 int     ripoffline(int, int (*)(WINDOW *, int));
 int     savetty(void);
-int     scanw(const char *, ...);
+int     scanw(const char *, ...) scanflike(1, 2);
 int     scr_dump(const char *);
 int     scr_init(const char *);
 int     scr_restore(const char *);
@@ -1260,10 +1265,10 @@ int     vid_attr(attr_t, short, void *);
 int     vidputs(chtype, int (*)(int));
 int     vid_puts(attr_t, short, void *, int (*)(int));
 int     vline(chtype, int);
-int     vw_printw(WINDOW *, const char *, va_list);
-int     vwprintw(WINDOW *, const char *, va_list);
-int     vw_scanw(WINDOW *, const char *, va_list);
-int     vwscanw(WINDOW *, const char *, va_list);
+int     vw_printw(WINDOW *, const char *, va_list) printflike(2, 0);
+int     vwprintw(WINDOW *, const char *, va_list) printflike(2, 0);
+int     vw_scanw(WINDOW *, const char *, va_list) scanflike(2, 0);
+int     vwscanw(WINDOW *, const char *, va_list) scanflike(2, 0);
 int     waddchnstr(WINDOW *, const chtype *, int);
 int     waddchstr(WINDOW *, const chtype *);
 int     waddch(WINDOW *, const chtype);
@@ -1306,10 +1311,10 @@ int     winsstr(WINDOW *, const char *);
 int     winstr(WINDOW *, char *);
 int     wmove(WINDOW *, int, int);
 int     wnoutrefresh(WINDOW *);
-int     wprintw(WINDOW *, const char *, ...);
+int     wprintw(WINDOW *, const char *, ...) printflike(2, 3);
 int     wredrawln(WINDOW *, int, int);
 int     wrefresh(WINDOW *);
-int     wscanw(WINDOW *, const char *, ...);
+int     wscanw(WINDOW *, const char *, ...) scanflike(2, 3);
 int     wscrl(WINDOW *, int);
 int     wsetscrreg(WINDOW *, int, int);
 int     wstandend(WINDOW *);
@@ -1386,8 +1391,9 @@ int     mvwin_wchnstr(WINDOW *, int, int, cchar_t *, int);
 int     mvwin_wchstr(WINDOW *, int, int, cchar_t *);
 int     mvwinwstr(WINDOW *, int, int, wchar_t *);
 int     mvwvline_set(WINDOW *, int, int, const cchar_t *, int);
-int     pecho_wchar(WINDOW *, const cchar_t*);
-int     setcchar(cchar_t*, const wchar_t*, const attr_t, short, const void*);
+int     pecho_wchar(WINDOW *, const cchar_t *);
+int     setcchar(cchar_t *, const wchar_t *, const attr_t,
+                 short, const void *);
 int     slk_wset(int, const wchar_t *, int);
 int     unget_wch(const wchar_t);
 int     vline_set(const cchar_t *, int);
@@ -1491,7 +1497,7 @@ char    wordchar(void);
 wchar_t *slk_wlabel(int);
 #endif
 
-void    PDC_debug(const char *, ...);
+void    PDC_debug(const char *, ...) printflike(1, 2);
 int     PDC_ungetch(int);
 int     PDC_set_blink(bool);
 int     PDC_set_line_color(short);
diff --git a/include/graphics/nxwidgets/cnxstring.hxx b/include/graphics/nxwidgets/cnxstring.hxx
index 525b98e3a..4bf4d94ec 100644
--- a/include/graphics/nxwidgets/cnxstring.hxx
+++ b/include/graphics/nxwidgets/cnxstring.hxx
@@ -510,7 +510,7 @@ namespace NXWidgets
      * @return New CNxString instance.
      */
 
-    static CNxString format(const char *fmt, ...);
+    static CNxString format(const char *fmt, ...) printflike(1, 2);
   };
 }
 
diff --git a/include/netutils/telnetc.h b/include/netutils/telnetc.h
index 163efdc86..66e9bc0b2 100644
--- a/include/netutils/telnetc.h
+++ b/include/netutils/telnetc.h
@@ -586,7 +586,8 @@ void telnet_begin_compress2(struct telnet_s *telnet);
  *
  ****************************************************************************/
 
-int telnet_printf(struct telnet_s *telnet, const char *fmt, ...);
+int telnet_printf(struct telnet_s *telnet, const char *fmt, ...)
+    printflike(2, 3);
 
 /****************************************************************************
  * Name: telnet_vprintf
@@ -598,7 +599,8 @@ int telnet_printf(struct telnet_s *telnet, const char *fmt, ...);
  *
  ****************************************************************************/
 
-int telnet_vprintf(struct telnet_s *telnet, const char *fmt, va_list va);
+int telnet_vprintf(struct telnet_s *telnet, const char *fmt, va_list va)
+    printflike(2, 0);
 
 /****************************************************************************
  * Name: telnet_raw_printf
@@ -619,7 +621,8 @@ int telnet_vprintf(struct telnet_s *telnet, const char *fmt, va_list va);
  *
  ****************************************************************************/
 
-int telnet_raw_printf(struct telnet_s *telnet, const char *fmt, ...);
+int telnet_raw_printf(struct telnet_s *telnet, const char *fmt, ...)
+    printflike(2, 3);
 
 /****************************************************************************
  * Name: telnet_raw_vprintf
@@ -631,7 +634,8 @@ int telnet_raw_printf(struct telnet_s *telnet, const char *fmt, ...);
  *
  ****************************************************************************/
 
-int telnet_raw_vprintf(struct telnet_s *telnet, const char *fmt, va_list va);
+int telnet_raw_vprintf(struct telnet_s *telnet, const char *fmt, va_list va)
+    printflike(2, 0);
 
 /****************************************************************************
  * Name: telnet_begin_newenviron
diff --git a/include/netutils/xmlrpc.h b/include/netutils/xmlrpc.h
index 067c04373..edf5d1684 100644
--- a/include/netutils/xmlrpc.h
+++ b/include/netutils/xmlrpc.h
@@ -40,11 +40,9 @@
  * POSSIBILITY OF SUCH DAMAGE.
  ****************************************************************************/
 
-/*
- *  Lightweight Embedded XML-RPC Server Types and Definitions
- *
- *  mtj@cogitollc.com
+/* Lightweight Embedded XML-RPC Server Types and Definitions
  *
+ * mtj@cogitollc.com
  */
 
 #ifndef __APPS_INCLUDE_NETUTILS_XMLRPC_H
@@ -86,13 +84,13 @@ struct xmlrpc_arg_s
     int i;
     char boolean;
     double d;
-    char string[CONFIG_XMLRPC_STRINGSIZE+1];
+    char string[CONFIG_XMLRPC_STRINGSIZE + 1];
   } u;
 };
 
 struct xmlrpc_s
 {
-  char  name[CONFIG_XMLRPC_STRINGSIZE+1];
+  char  name[CONFIG_XMLRPC_STRINGSIZE + 1];
   struct xmlrpc_arg_s arguments[MAX_ARGS];
   char  args[MAX_ARGS];
   int   argsize;
@@ -104,7 +102,7 @@ struct xmlrpc_s
 struct xmlrpc_entry_s
 {
   struct xmlrpc_entry_s *next;
-  int (*func)(struct xmlrpc_s*);
+  int (*func)(struct xmlrpc_s *);
   char *name;
 };
 
diff --git a/interpreters/bas/bas_error.h b/interpreters/bas/bas_error.h
index d0f50a035..0d2697aeb 100644
--- a/interpreters/bas/bas_error.h
+++ b/interpreters/bas/bas_error.h
@@ -83,7 +83,7 @@
 #define STRAYELSE2         STATIC+46, _("`else' without `end if'")
 #define STRAYENDIF         STATIC+47, _("`end if' without multiline `if' or `else'")
 #define STRAYSUBEND        STATIC+49, _("`subend', `end sub' or `endproc' without `sub' or `def proc' inside %s")
-#define STRAYSUBEXIT       STATIC+50, _("`subexit' without `sub' inside %s")
+#define STRAYSUBEXIT       STATIC+50, _("`subexit' without `sub' inside")
 #define STRAYENDSELECT     STATIC+51, _("`end select' without `select case'")
 #define STRAYENDFN         STATIC+52, _("`end function' without `def fn' or `function'")
 #define STRAYENDEQ         STATIC+53, _("`=' returning from function without `def fn'")
diff --git a/interpreters/bas/bas_statement.c b/interpreters/bas/bas_statement.c
index 9638b6cf9..194123677 100644
--- a/interpreters/bas/bas_statement.c
+++ b/interpreters/bas/bas_statement.c
@@ -1241,7 +1241,7 @@ struct Value *stmt_EDIT(struct Value *value)
 
   return (struct Value *)0;
 #else
-  return Value_new_ERROR(value, NOTAVAILABLE, strerror(ENOSYS));
+  return Value_new_ERROR(value, NOTAVAILABLE);
 #endif
 }
 
@@ -3526,7 +3526,7 @@ struct Value *stmt_MATINPUT(struct Value *value)
 
           if (var->dim != 1 && var->dim != 2)
             {
-              return Value_new_ERROR(value, NOMATRIX, var->dim);
+              return Value_new_ERROR(value, DIMENSION);
             }
 
           columns = var->dim == 1 ? 0 : var->geometry[1];
@@ -5772,7 +5772,7 @@ struct Value *stmt_SHELL(struct Value *value)
 
   return (struct Value *)0;
 #else
-  return Value_new_ERROR(value, NOTAVAILABLE, strerror(ENOSYS));
+  return Value_new_ERROR(value, NOTAVAILABLE);
 #endif
 }
 
diff --git a/interpreters/bas/bas_str.h b/interpreters/bas/bas_str.h
index 5c7d02796..97506812c 100644
--- a/interpreters/bas/bas_str.h
+++ b/interpreters/bas/bas_str.h
@@ -14,7 +14,7 @@
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
@@ -64,7 +64,8 @@ struct String *String_clone(struct String *this, const struct String *clon);
 int String_appendString(struct String *this, const struct String *app);
 int String_appendChar(struct String *this, char ch);
 int String_appendChars(struct String *this, const char *ch);
-int String_appendPrintf(struct String *this, const char *fmt, ...);
+int String_appendPrintf(struct String *this, const char *fmt, ...)
+    printflike(2, 3);
 int String_insertChar(struct String *this, size_t where, char ch);
 int String_delete(struct String *this, size_t where, size_t len);
 void String_ucase(struct String *this);
diff --git a/interpreters/bas/bas_value.h b/interpreters/bas/bas_value.h
index e364dba54..68da43967 100644
--- a/interpreters/bas/bas_value.h
+++ b/interpreters/bas/bas_value.h
@@ -14,7 +14,7 @@
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
@@ -58,7 +58,7 @@
 
 enum ValueType
 {
-  V_ERROR=1,
+  V_ERROR = 1,
   V_INTEGER,
   V_NIL,
   V_REAL,
@@ -71,12 +71,16 @@ struct Value
   enum ValueType type;
   union
   {
-    /* V_ERROR   */ struct { char *msg; long int code; } error;
-    /* V_INTEGER */ long int integer;
-    /* V_NIL     */
-    /* V_REAL    */ double real;
-    /* V_STRING  */ struct String string;
-    /* V_VOID    */
+    struct                /* V_ERROR   */
+    {
+      char *msg;
+      long int code;
+    } error;
+    long int integer;     /* V_INTEGER */
+                          /* V_NIL     */
+    double real;          /* V_REAL    */
+    struct String string; /* V_STRING  */
+                          /* V_VOID    */
   } u;
 };
 
@@ -84,7 +88,7 @@ struct Value
  * Public Data
  ****************************************************************************/
 
-extern const enum ValueType Value_commonType[V_VOID+1][V_VOID+1];
+extern const enum ValueType Value_commonType[V_VOID + 1][V_VOID + 1];
 
 /****************************************************************************
  * Public Function Prototypes
@@ -99,7 +103,7 @@ double Value_vald(const char *s, char **end, int *overflow);
 
 struct Value *Value_new_NIL(struct Value *this);
 struct Value *Value_new_ERROR(struct Value *this, int code,
-                              const char *error, ...);
+                              const char *error, ...) printflike(3, 4);
 struct Value *Value_new_INTEGER(struct Value *this, int n);
 struct Value *Value_new_REAL(struct Value *this, double n);
 struct Value *Value_new_STRING(struct Value *this);
diff --git a/modbus/nuttx/port.h b/modbus/nuttx/port.h
index 90fadab60..2fc4b1657 100644
--- a/modbus/nuttx/port.h
+++ b/modbus/nuttx/port.h
@@ -81,7 +81,7 @@ typedef enum
 void vMBPortEnterCritical(void);
 void vMBPortExitCritical(void);
 void vMBPortLog(eMBPortLogLevel eLevel, const char *szModule,
-                const char *szFmt, ...);
+                const char *szFmt, ...) printflike(3, 4);
 void vMBPortTimerPoll(void);
 bool xMBPortSerialPoll(void);
 bool xMBPortSerialSetTimeout(uint32_t dwTimeoutMs);
@@ -90,7 +90,7 @@ bool xMBPortSerialSetTimeout(uint32_t dwTimeoutMs);
   void vMBMasterPortEnterCritical(void);
   void vMBMasterPortExitCritical(void);
   void vMBMasterPortLog(eMBPortLogLevel eLevel, const char *szModule,
-                        const char *szFmt, ...);
+                        const char *szFmt, ...) printflike(3, 4);
   void vMBMasterPortTimerPoll(void);
   bool xMBMasterPortSerialPoll(void);
   bool xMBMasterPortSerialSetTimeout(uint32_t dwTimeoutMs);
diff --git a/netutils/ftpc/ftpc_getfile.c b/netutils/ftpc/ftpc_getfile.c
index 968ff6286..902d61aba 100644
--- a/netutils/ftpc/ftpc_getfile.c
+++ b/netutils/ftpc/ftpc_getfile.c
@@ -25,6 +25,7 @@
 #include "ftpc_config.h"
 
 #include <sys/stat.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -95,7 +96,7 @@ static int ftpc_recvinit(struct ftpc_session_s *session,
        * transfer should start.  This must come after PORT or PASV commands.
        */
 
-      ret = ftpc_cmd(session, "REST %ld", offset);
+      ret = ftpc_cmd(session, "REST %" PRIdOFF, offset);
       if (ret < 0)
         {
           nwarn("WARNING: REST command failed: %d\n", errno);
diff --git a/netutils/ftpc/ftpc_internal.h b/netutils/ftpc/ftpc_internal.h
index 5cce95a64..5546e889a 100644
--- a/netutils/ftpc/ftpc_internal.h
+++ b/netutils/ftpc/ftpc_internal.h
@@ -226,7 +226,8 @@ EXTERN int ftpc_relogin(FAR struct ftpc_session_s *session);
 /* FTP helpers */
 
 EXTERN void ftpc_reset(struct ftpc_session_s *session);
-EXTERN int ftpc_cmd(struct ftpc_session_s *session, const char *cmd, ...);
+EXTERN int ftpc_cmd(struct ftpc_session_s *session, const char *cmd, ...)
+           printflike(2, 3);
 EXTERN int fptc_getreply(struct ftpc_session_s *session);
 EXTERN FAR const char *ftpc_lpwd(void);
 EXTERN int ftpc_xfrmode(struct ftpc_session_s *session, uint8_t xfrmode);
@@ -252,7 +253,7 @@ EXTERN void ftpc_sockcopy(FAR struct ftpc_socket_s *dest,
 /* Socket I/O helpers */
 
 EXTERN int ftpc_sockprintf(FAR struct ftpc_socket_s *sock,
-                           const char *fmt, ...);
+                           const char *fmt, ...) printflike(2, 3);
 EXTERN void ftpc_timeout(wdparm_t arg);
 
 /* Transfer helpers */
diff --git a/netutils/ftpc/ftpc_putfile.c b/netutils/ftpc/ftpc_putfile.c
index 5b51c39c2..feeaf4313 100644
--- a/netutils/ftpc/ftpc_putfile.c
+++ b/netutils/ftpc/ftpc_putfile.c
@@ -26,6 +26,7 @@
 
 #include <sys/stat.h>
 #include <sys/sendfile.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -263,7 +264,7 @@ static int ftpc_sendfile(struct ftpc_session_s *session, const char *path,
 
   if (session->offset > 0)
     {
-      ret = ftpc_cmd(session, "REST %ld", session->offset);
+      ret = ftpc_cmd(session, "REST %" PRIdOFF, session->offset);
       session->size = session->offset;
     }
 
diff --git a/netutils/ftpd/ftpd.c b/netutils/ftpd/ftpd.c
index 4ffc70688..f5322f569 100644
--- a/netutils/ftpd/ftpd.c
+++ b/netutils/ftpd/ftpd.c
@@ -108,7 +108,8 @@ static int ftpd_accept(int sd, FAR void *addr, FAR socklen_t *addrlen,
 static ssize_t ftpd_recv(int sd, FAR void *data, size_t size, int timeout);
 static ssize_t ftpd_send(int sd, FAR const void *data, size_t size,
                          int timeout);
-static ssize_t ftpd_response(int sd, int timeout, FAR const char *fmt, ...);
+static ssize_t ftpd_response(int sd, int timeout, FAR const char *fmt, ...)
+               printflike(3, 4);
 
 static int ftpd_dataopen(FAR struct ftpd_session_s *session);
 static int ftpd_dataclose(FAR struct ftpd_session_s *session);
diff --git a/nshlib/nsh_console.c b/nshlib/nsh_console.c
index 3ee7241a5..d383c8e15 100644
--- a/nshlib/nsh_console.c
+++ b/nshlib/nsh_console.c
@@ -63,9 +63,9 @@ static void nsh_consolerelease(FAR struct nsh_vtbl_s *vtbl);
 static ssize_t nsh_consolewrite(FAR struct nsh_vtbl_s *vtbl,
   FAR const void *buffer, size_t nbytes);
 static int nsh_consoleoutput(FAR struct nsh_vtbl_s *vtbl,
-  FAR const char *fmt, ...);
+  FAR const char *fmt, ...) printflike(2, 3);
 static int nsh_erroroutput(FAR struct nsh_vtbl_s *vtbl,
-  FAR const char *fmt, ...);
+  FAR const char *fmt, ...) printflike(2, 3);
 static FAR char *nsh_consolelinebuffer(FAR struct nsh_vtbl_s *vtbl);
 static void nsh_consoleredirect(FAR struct nsh_vtbl_s *vtbl, int fd,
   FAR uint8_t *save);
diff --git a/nshlib/nsh_console.h b/nshlib/nsh_console.h
index 95fdbbf6f..895f98d51 100644
--- a/nshlib/nsh_console.h
+++ b/nshlib/nsh_console.h
@@ -112,8 +112,10 @@ struct nsh_vtbl_s
   void (*release)(FAR struct nsh_vtbl_s *vtbl);
   ssize_t (*write)(FAR struct nsh_vtbl_s *vtbl, FAR const void *buffer,
                    size_t nbytes);
-  int (*error)(FAR struct nsh_vtbl_s *vtbl, FAR const char *fmt, ...);
-  int (*output)(FAR struct nsh_vtbl_s *vtbl, FAR const char *fmt, ...);
+  int (*error)(FAR struct nsh_vtbl_s *vtbl, FAR const char *fmt, ...)
+      printflike(2, 3);
+  int (*output)(FAR struct nsh_vtbl_s *vtbl, FAR const char *fmt, ...)
+      printflike(2, 3);
   FAR char *(*linebuffer)(FAR struct nsh_vtbl_s *vtbl);
   void (*redirect)(FAR struct nsh_vtbl_s *vtbl, int fd, FAR uint8_t *save);
   void (*undirect)(FAR struct nsh_vtbl_s *vtbl, FAR uint8_t *save);
diff --git a/nshlib/nsh_dbgcmds.c b/nshlib/nsh_dbgcmds.c
index 08289ad5f..e5fb1a6ff 100644
--- a/nshlib/nsh_dbgcmds.c
+++ b/nshlib/nsh_dbgcmds.c
@@ -166,7 +166,7 @@ int cmd_mb(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
 
           /* Make sure we end it with a newline */
 
-          nsh_output(vtbl, "\n", *ptr);
+          nsh_output(vtbl, "\n");
         }
     }
 
@@ -222,7 +222,7 @@ int cmd_mh(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
 
           /* Make sure we end it with a newline */
 
-          nsh_output(vtbl, "\n", *ptr);
+          nsh_output(vtbl, "\n");
         }
     }
 
@@ -252,7 +252,7 @@ int cmd_mw(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
         {
           /* Print the value at the address */
 
-          nsh_output(vtbl, "  %p = 0x%08x", ptr, *ptr);
+          nsh_output(vtbl, "  %p = 0x%08" PRIx32, ptr, *ptr);
 
           /* Are we supposed to write a value to this address? */
 
@@ -264,12 +264,12 @@ int cmd_mw(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
                */
 
               *ptr = mem.dm_value;
-              nsh_output(vtbl, " -> 0x%08x", *ptr);
+              nsh_output(vtbl, " -> 0x%08" PRIx32, *ptr);
             }
 
           /* Make sure we end it with a newline */
 
-          nsh_output(vtbl, "\n", *ptr);
+          nsh_output(vtbl, "\n");
         }
     }
 
diff --git a/nshlib/nsh_fscmds.c b/nshlib/nsh_fscmds.c
index 45c6f64ac..4f1afff8f 100644
--- a/nshlib/nsh_fscmds.c
+++ b/nshlib/nsh_fscmds.c
@@ -25,6 +25,7 @@
 #include <nuttx/config.h>
 
 #include <sys/types.h>
+#include <inttypes.h>
 #include <stdint.h>
 #include <stdbool.h>
 
@@ -245,7 +246,7 @@ static int ls_handler(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
 
       if ((lsflags & LSFLAGS_SIZE) != 0)
         {
-          nsh_output(vtbl, "%8d", buf.st_size);
+          nsh_output(vtbl, "%8" PRIdOFF, buf.st_size);
         }
     }
 
@@ -1873,7 +1874,7 @@ int cmd_cmp(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
       if (nbytesread1 != nbytesread2 ||
           memcmp(buf1, buf2, nbytesread1) != 0)
         {
-          nsh_error(vtbl, "files differ: byte %u\n", total_read);
+          nsh_error(vtbl, "files differ: byte %" PRIuOFF "\n", total_read);
           goto errout_with_fd2;
         }
 
diff --git a/nshlib/nsh_fsutils.c b/nshlib/nsh_fsutils.c
index 6b3c27402..9f16f6036 100644
--- a/nshlib/nsh_fsutils.c
+++ b/nshlib/nsh_fsutils.c
@@ -75,15 +75,11 @@ int nsh_catfile(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
                   strlen(CONFIG_NSH_PROC_MOUNTPOINT)) == 0)
         {
           nsh_error(vtbl,
-                    "nsh: %s: Could not open %s (is procfs mounted?): %d\n",
-                    cmd, filepath, NSH_ERRNO);
+                    "nsh: %s: Could not open %s (is procfs mounted?)\n",
+                    cmd, filepath);
         }
-      else
 #endif
-        {
-          nsh_error(vtbl, g_fmtcmdfailed, cmd, "open", NSH_ERRNO);
-        }
-
+      nsh_error(vtbl, g_fmtcmdfailed, cmd, "open", NSH_ERRNO);
       return ERROR;
     }
 
@@ -322,15 +318,11 @@ int nsh_writefile(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
                   strlen(CONFIG_NSH_PROC_MOUNTPOINT)) == 0)
         {
           nsh_error(vtbl,
-                    "nsh: %s: Could not open %s (is procfs mounted?): %d\n",
-                    cmd, filepath, NSH_ERRNO);
+                    "nsh: %s: Could not open %s (is procfs mounted?)\n",
+                    cmd, filepath);
         }
-      else
 #endif
-        {
-          nsh_error(vtbl, g_fmtcmdfailed, cmd, "open", NSH_ERRNO);
-        }
-
+      nsh_error(vtbl, g_fmtcmdfailed, cmd, "open", NSH_ERRNO);
       return ERROR;
     }
 
@@ -384,15 +376,11 @@ int nsh_foreach_direntry(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
                   strlen(CONFIG_NSH_PROC_MOUNTPOINT)) == 0)
         {
           nsh_error(vtbl,
-                    "nsh: %s: Could not open %s (is procfs mounted?): %d\n",
-                    cmd, dirpath, NSH_ERRNO);
+                    "nsh: %s: Could not open %s (is procfs mounted?)\n",
+                    cmd, dirpath);
         }
-      else
 #endif
-        {
-          nsh_error(vtbl, g_fmtnosuch, cmd, "directory", dirpath);
-        }
-
+      nsh_error(vtbl, g_fmtcmdfailed, cmd, "opendir", NSH_ERRNO);
       return ERROR;
     }
 
diff --git a/nshlib/nsh_netcmds.c b/nshlib/nsh_netcmds.c
index 58637f59d..8acd5b6b0 100644
--- a/nshlib/nsh_netcmds.c
+++ b/nshlib/nsh_netcmds.c
@@ -377,8 +377,9 @@ static int nsh_foreach_netdev(nsh_netdev_callback_t callback,
   if (dir == NULL)
     {
       nsh_error(vtbl,
-                "nsh: %s: Could not open %s/net (is procfs mounted?): %d\n",
-                cmd, CONFIG_NSH_PROC_MOUNTPOINT, NSH_ERRNO);
+                "nsh: %s: Could not open %s/net (is procfs mounted?)\n",
+                cmd, CONFIG_NSH_PROC_MOUNTPOINT);
+      nsh_error(vtbl, g_fmtcmdfailed, cmd, "opendir", NSH_ERRNO);
       return ERROR;
     }
 
diff --git a/nshlib/nsh_printf.c b/nshlib/nsh_printf.c
index 01d2617b6..e4e1ac748 100644
--- a/nshlib/nsh_printf.c
+++ b/nshlib/nsh_printf.c
@@ -48,7 +48,7 @@ int cmd_printf(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 {
   FAR char *fmt;
   char ch;
-  uint32_t value;
+  unsigned int value;
   int len;
   int i;
 
diff --git a/nshlib/nsh_proccmds.c b/nshlib/nsh_proccmds.c
index 195bb4bfe..86d15a27d 100644
--- a/nshlib/nsh_proccmds.c
+++ b/nshlib/nsh_proccmds.c
@@ -233,13 +233,13 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
   int ret;
   int i;
 #if defined(CONFIG_DEBUG_MM) && !defined(CONFIG_NSH_DISABLE_PSHEAPUSAGE)
-  uint32_t heap_size;
+  unsigned long heap_size = 0;
 #endif
 #if !defined(CONFIG_NSH_DISABLE_PSSTACKUSAGE)
-  uint32_t stack_size;
+  unsigned long stack_size = 0;
 #ifdef CONFIG_STACK_COLORATION
-  uint32_t stack_used;
-  uint32_t stack_filled;
+  unsigned long stack_used = 0;
+  unsigned long stack_filled = 0;
 #endif
 #endif
 
@@ -343,9 +343,7 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
 #if defined(CONFIG_DEBUG_MM) && !defined(CONFIG_NSH_DISABLE_PSHEAPUSAGE)
   /* Get the Heap AllocSize */
 
-  heap_size = 0;
   filepath  = NULL;
-
   ret = asprintf(&filepath, "%s/%s/heap", dirpath, entryp->d_name);
   if (ret < 0 || filepath == NULL)
     {
@@ -393,7 +391,7 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
 
               if (strncmp(line, g_heapsize, strlen(g_heapsize)) == 0)
                 {
-                  heap_size = (uint32_t)atoi(&line[12]);
+                  heap_size = strtoul(&line[12], NULL, 0);
                   break;
                 }
             }
@@ -401,18 +399,13 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
         }
     }
 
-  nsh_output(vtbl, "%08u ", (unsigned int)heap_size);
+  nsh_output(vtbl, "%08lu ", heap_size);
 #endif
 
 #if !defined(CONFIG_NSH_DISABLE_PSSTACKUSAGE)
   /* Get the StackSize and StackUsed */
 
-  stack_size = 0;
-#ifdef CONFIG_STACK_COLORATION
-  stack_used = 0;
-#endif
   filepath   = NULL;
-
   ret = asprintf(&filepath, "%s/%s/stack", dirpath, entryp->d_name);
   if (ret < 0 || filepath == NULL)
     {
@@ -461,12 +454,12 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
 
               if (strncmp(line, g_stacksize, strlen(g_stacksize)) == 0)
                 {
-                  stack_size = (uint32_t)atoi(&line[12]);
+                  stack_size = strtoul(&line[12], NULL, 0);
                 }
 #ifdef CONFIG_STACK_COLORATION
               else if (strncmp(line, g_stackused, strlen(g_stackused)) == 0)
                 {
-                  stack_used = (uint32_t)atoi(&line[12]);
+                  stack_used = strtoul(&line[12], NULL, 0);
                 }
 #endif
             }
@@ -474,12 +467,11 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
         }
     }
 
-  nsh_output(vtbl, "%06u ", (unsigned int)stack_size);
+  nsh_output(vtbl, "%06lu ", stack_size);
 
 #ifdef CONFIG_STACK_COLORATION
-  nsh_output(vtbl, "%06u ", (unsigned int)stack_used);
+  nsh_output(vtbl, "%06lu ", stack_used);
 
-  stack_filled = 0;
   if (stack_size > 0 && stack_used > 0)
     {
       /* Use fixed-point math with one decimal place */
@@ -489,7 +481,7 @@ static int ps_callback(FAR struct nsh_vtbl_s *vtbl, FAR const char *dirpath,
 
   /* Additionally print a '!' if the stack is filled more than 80% */
 
-  nsh_output(vtbl, "%3d.%1d%%%c ",
+  nsh_output(vtbl, "%3lu.%lu%%%c ",
              stack_filled / 10, stack_filled % 10,
              (stack_filled >= 10 * 80 ? '!' : ' '));
 #endif
diff --git a/nshlib/nsh_syscmds.c b/nshlib/nsh_syscmds.c
index 620a246ce..87c4eaac0 100644
--- a/nshlib/nsh_syscmds.c
+++ b/nshlib/nsh_syscmds.c
@@ -217,7 +217,7 @@ int cmd_pmconfig(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
       boardctl(BOARDIOC_PM_CONTROL, (uintptr_t)&ctrl);
       sleep_count = ctrl.count;
 
-      nsh_output(vtbl, "Last state %d, Next state %d",
+      nsh_output(vtbl, "Last state %d, Next state %d"
                  "PM stay [%d, %d, %d, %d]\n",
                  last_state, next_state, normal_count, idle_count,
                  standby_count, sleep_count);
@@ -611,7 +611,7 @@ int cmd_uname(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
               nsh_output(vtbl, " ");
             }
 
-          nsh_output(vtbl, str);
+          nsh_output(vtbl, "%s", str);
           first = false;
         }
     }
diff --git a/system/cle/cle.c b/system/cle/cle.c
index d49066f39..0ec857718 100644
--- a/system/cle/cle.c
+++ b/system/cle/cle.c
@@ -153,7 +153,7 @@ struct cle_s
  ****************************************************************************/
 
 #if CONFIG_SYSTEM_CLE_DEBUGLEVEL > 0
-static void     cle_debug(FAR const char *fmt, ...);
+static void     cle_debug(FAR const char *fmt, ...) printflike(1, 2);
 #endif
 
 /* Low-level display and data entry functions */
diff --git a/system/hexed/include/hexed.h b/system/hexed/include/hexed.h
index 3eb4880ca..38265e460 100644
--- a/system/hexed/include/hexed.h
+++ b/system/hexed/include/hexed.h
@@ -5,7 +5,8 @@
  *   Copyright (c) 2011, B.ZaaR, All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
+ * modification, are permitted provided that the following conditions are
+ * met:
  *
  *   Redistributions of source code must retain the above copyright notice,
  *   this list of conditions and the following disclaimer.
@@ -18,7 +19,7 @@
  *   products derived from this software without specific prior written
  *   permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
diff --git a/system/i2c/i2c_main.c b/system/i2c/i2c_main.c
index f140c17f6..b8f011dc1 100644
--- a/system/i2c/i2c_main.c
+++ b/system/i2c/i2c_main.c
@@ -140,7 +140,7 @@ static int i2ccmd_help(FAR struct i2ctool_s *i2ctool, int argc, char **argv)
                  i2ctool->autoincr ? "YES" : "NO");
   i2ctool_printf(i2ctool,
                  "  [-f freq] I2C frequency."
-                 "  Default: %d Current: %d\n",
+                 "  Default: %d Current: %" PRIu32 "\n",
                  CONFIG_I2CTOOL_DEFFREQ, i2ctool->freq);
 
   i2ctool_printf(i2ctool, "\nSpecial non-sticky options:\n");
diff --git a/system/i2c/i2ctool.h b/system/i2c/i2ctool.h
index ef9f07f82..fdad24a70 100644
--- a/system/i2c/i2ctool.h
+++ b/system/i2c/i2ctool.h
@@ -170,7 +170,8 @@ extern const char g_i2cxfrerror[];
 
 ssize_t i2ctool_write(FAR struct i2ctool_s *i2ctool, FAR const void *buffer,
                       size_t nbytes);
-int i2ctool_printf(FAR struct i2ctool_s *i2ctool, const char *fmt, ...);
+int i2ctool_printf(FAR struct i2ctool_s *i2ctool, const char *fmt, ...)
+    printflike(2, 3);
 void i2ctool_flush(FAR struct i2ctool_s *i2ctool);
 void i2ctool_hexdump(FILE *outstream, void *addr, int len);
 
diff --git a/system/spi/spi_main.c b/system/spi/spi_main.c
index c78a56b3c..68a6461c3 100644
--- a/system/spi/spi_main.c
+++ b/system/spi/spi_main.c
@@ -122,7 +122,7 @@ static int spicmd_help(FAR struct spitool_s *spitool, int argc,
                  CONFIG_SPITOOL_DEFCMD, spitool->command);
 #endif
   spitool_printf(spitool, "  [-f freq] SPI frequency.  "
-                          "Default: %d Current: %d\n",
+                          "Default: %d Current: %" PRIu32 "\n",
                  CONFIG_SPITOOL_DEFFREQ, spitool->freq);
 
   spitool_printf(spitool, "  [-m mode] Mode for transfer.  "
@@ -130,23 +130,24 @@ static int spicmd_help(FAR struct spitool_s *spitool, int argc,
                  CONFIG_SPITOOL_DEFMODE, spitool->mode);
 
   spitool_printf(spitool, "  [-n CSn] chip select number.  "
-                          "Default: %d Current: %d\n",
+                          "Default: %d Current: %" PRIu32 "\n",
                  0, spitool->csn);
 
   spitool_printf(spitool, "  [-t devtype] Chip Select type "
                           "(see spi_devtype_e).  "
-                          "Default: %d Current: %d\n",
+                          "Default: %d Current: %" PRIu32 "\n",
                  SPIDEVTYPE_USER, spitool->devtype);
 
   spitool_printf(spitool, "  [-u udelay] Delay after transfer in uS.  "
-                          "Default: 0 Current: %d\n", spitool->udelay);
+                          "Default: 0 Current: %" PRIu32 "\n",
+                 spitool->udelay);
 
   spitool_printf(spitool, "  [-w width] Width of bus.  "
                           "Default: %d Current: %d\n",
                  CONFIG_SPITOOL_DEFWIDTH, spitool->width);
 
   spitool_printf(spitool, "  [-x count] Words to exchange  "
-                          "Default: %d Current: %d Max: %d\n",
+                          "Default: %d Current: %" PRIu32 " Max: %d\n",
                  CONFIG_SPITOOL_DEFWORDS, spitool->count, MAX_XDATA);
 
   spitool_printf(spitool, "\nNOTES:\n");
diff --git a/system/spi/spitool.h b/system/spi/spitool.h
index fea92ad4a..b1cb66b43 100644
--- a/system/spi/spitool.h
+++ b/system/spi/spitool.h
@@ -176,7 +176,8 @@ extern const char g_spixfrerror[];
 ssize_t spitool_exchange(FAR struct spitool_s *spitool,
                          FAR const void *outbuffer, size_t noutbytes,
                          FAR void *inbuffer, size_t ninbytes);
-int spitool_printf(FAR struct spitool_s *spitool, const char *fmt, ...);
+int spitool_printf(FAR struct spitool_s *spitool, const char *fmt, ...)
+    printflike(2, 3);
 void spitool_flush(FAR struct spitool_s *spitool);
 
 /* Command handlers */
diff --git a/system/vi/vi.c b/system/vi/vi.c
index 63d9169fd..805314605 100644
--- a/system/vi/vi.c
+++ b/system/vi/vi.c
@@ -391,7 +391,7 @@ static void     vi_clrscreen(FAR struct vi_s *vi);
 /* Final Line display */
 
 static void     vi_printf(FAR struct vi_s *vi, FAR const char *prefix,
-                  FAR const char *fmt, ...);
+                  FAR const char *fmt, ...) printflike(3, 4);
 
 /* Line positioning */