Print which option was in error along with usage message

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

4 files changed, 17 insertions, 12 deletions

diff --git a/configure.ac b/configure.ac
index 8ec6674..99e1722 100644
--- a/configure.ac
+++ b/configure.ac
@@ -48,7 +48,7 @@ if test x$use_xkb != xno ; then
 fi
 
 # Checks for pkg-config packages
-PKG_CHECK_MODULES(XWD, [x11 xproto >= 7.0.17 ${XKBMODULE}])
+PKG_CHECK_MODULES(XWD, [x11 xproto >= 7.0.25 ${XKBMODULE}])
 
 AC_CONFIG_FILES([
 	Makefile
diff --git a/dsimple.c b/dsimple.c
index fa31e8f..4fb1a81 100644
--- a/dsimple.c
+++ b/dsimple.c
@@ -76,7 +76,7 @@ char *Get_Display_Name(
 	char *arg = argv[i];
 
 	if (!strcmp (arg, "-display") || !strcmp (arg, "-d")) {
-	    if (++i >= argc) usage ();
+	    if (++i >= argc) usage ("-display requires an argument");
 
 	    displayname = argv[i];
 	    *pargc -= 2;
@@ -180,7 +180,7 @@ Window Select_Window_Args(
 	nargv = argv+1; argc = ARGC;
 #define OPTION argv[0]
 #define NXTOPTP ++argv, --argc>0
-#define NXTOPT if (++argv, --argc==0) usage()
+#define NXTOPT(arg) if (++argv, --argc==0) usage(arg " requires an argument")
 #define COPYOPT nargv++[0]=OPTION, nargc++
 
 	while (NXTOPTP) {
@@ -195,7 +195,7 @@ Window Select_Window_Args(
 			continue;
 		}
 		if (!strcmp(OPTION, "-name")) {
-			NXTOPT;
+			NXTOPT("-name");
 			w = Window_With_Name(dpy, RootWindow(dpy, screen),
 					     OPTION);
 			if (!w)
@@ -203,7 +203,7 @@ Window Select_Window_Args(
 			continue;
 		}
 		if (!strcmp(OPTION, "-id")) {
-			NXTOPT;
+			NXTOPT("-id");
 			w=0;
 			sscanf(OPTION, "0x%lx", &w);
 			if (!w)
diff --git a/dsimple.h b/dsimple.h
index b0422bd..18679b8 100644
--- a/dsimple.h
+++ b/dsimple.h
@@ -61,7 +61,7 @@ Display *Open_Display(const char *);
 void Setup_Display_And_Screen(int *, char **);
 void Close_Display(void);
 Window Select_Window_Args(int *, char **);
-void usage(void) _X_NORETURN;
+void usage(const char *errmsg) _X_NORETURN _X_COLD;
 
 #define X_USAGE "[host:display]"              /* X arguments handled by
 						 Get_Display_Name */
@@ -76,5 +76,5 @@ void usage(void) _X_NORETURN;
 
 Window Select_Window(Display *, int);
 Window Window_With_Name(Display *, Window, const char *);
-void Fatal_Error(const char *, ...) _X_NORETURN _X_ATTRIBUTE_PRINTF(1, 2);
+void Fatal_Error(const char *, ...) _X_NORETURN _X_ATTRIBUTE_PRINTF(1, 2) _X_COLD;
 void outl(const char *, ...) _X_ATTRIBUTE_PRINTF(1, 2);
diff --git a/xwd.c b/xwd.c
index 85734ea..d446bd5 100644
--- a/xwd.c
+++ b/xwd.c
@@ -163,9 +163,9 @@ main(int argc, char **argv)
 	    continue;
 	}
 	if (!strcmp(argv[i], "-help"))
-	  usage();
+	  usage(NULL);
 	if (!strcmp(argv[i], "-out")) {
-	    if (++i >= argc) usage();
+	    if (++i >= argc) usage("-out requires an argument");
 	    if (!(out_file = fopen(argv[i], "wb")))
 	      Fatal_Error("Can't open output file as specified.");
 	    standard_out = False;
@@ -184,7 +184,7 @@ main(int argc, char **argv)
 	    continue;
 	}
 	if (!strcmp(argv[i], "-add")) {
-	    if (++i >= argc) usage();
+	    if (++i >= argc) usage("-add requires an argument");
 	    add_pixel_value = parse_long (argv[i]);
 	    continue;
 	}
@@ -196,7 +196,9 @@ main(int argc, char **argv)
 	    silent = True;
 	    continue;
 	}
-	usage();
+	fprintf (stderr, "%s: unrecognized argument '%s'\n",
+		 program_name, argv[i]);
+	usage(NULL);
     }
 #ifdef WIN32
     if (standard_out)
@@ -518,8 +520,11 @@ Window_Dump(Window window, FILE *out)
  * Report the syntax for calling xwd.
  */
 void
-usage(void)
+usage(const char *errmsg)
 {
+    if (errmsg != NULL)
+        fprintf (stderr, "%s: %s\n", program_name, errmsg);
+
     fprintf (stderr,
 "usage: %s [-display host:dpy] [-debug] [-help] %s [-nobdrs] [-out <file>]",
 	   program_name, "[{-root|-id <id>|-name <name>}]");