uemacs: Add --help option.

Add a basic usage() function to support the --help option.

Signed-off-by: Thiago Farina <tfransosi@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

display.c

@@ -1,4 +1,4 @@
-/*	DISPLAY.C
+/*	display.c
  *
  * The functions in this file handle redisplay. There are two halves, the
  * ones that update the virtual display screen, and the ones that make the
@@ -15,6 +15,7 @@
 #include "estruct.h"
 #include "edef.h"
 #include "efunc.h"
+#include "version.h"
 
 struct video {
 	int v_flag;		/* Flags */
@@ -1132,7 +1133,7 @@ static void modeline(struct window *wp)
 	n = 2;
 
 	strcpy(tline, " ");
-	strcat(tline, PROGNAME);
+	strcat(tline, PROGRAM_NAME_LONG);
 	strcat(tline, " ");
 	strcat(tline, VERSION);
 	strcat(tline, ": ");

estruct.h

@@ -21,24 +21,11 @@
 #undef	CTRLZ
 #endif
 
-/*	Program Identification.....
-
-	PROGNAME should always be MicroEMACS for a distibrution
-	unmodified version. People using MicroEMACS as a shell
-	for other products should change this to reflect their
-	product. Macros can query this via the $progname variable
-
-	this version in called uEmacs/PK
-*/
-
-#define	PROGNAME	"uEmacs/PK"
-#define	VERSION		"4.0.15"
-
-/*	Machine/OS definitions			*/
+/* Machine/OS definitions. */
 
 #if defined(AUTOCONF) || defined(MSDOS) || defined(BSD) || defined(SYSV) || defined(VMS)
 
-/*  make an intelligent guess about the target system */
+/* Make an intelligent guess about the target system. */
 
 #if defined(__TURBOC__)
 #define MSDOS 1 /* MS/PC DOS 3.1-4.0 with Turbo C 2.0 */
@@ -72,7 +59,7 @@
 #define VMS 0
 #endif
 
-#define	V7	0		/* no more */
+#define	V7 0 /* No more. */
 
 #else
 
@@ -130,7 +117,7 @@
 #define	TERMCAP	UNIX
 #define	IBMPC	MSDOS
 
-#endif				/*autoconf */
+#endif /* Autoconf. */
 
 /*	Configuration options	*/
 
@@ -159,7 +146,7 @@
 #define	FILOCK	BSD
 #endif
 
-#endif				/* autoconf */
+#endif /* Autoconf. */
 
 #define	ISRCH	1  /* Incremental searches like ITS EMACS          */
 #define	WORDPRO	1  /* Advanced word processing features            */
@@ -185,13 +172,13 @@
 #define	XONXOFF	(UNIX | VMS)
 #define	NATIONL	(UNIX | VMS)
 
-#endif				/* autoconf */
+#endif /* Autoconf. */
 
 #define	PKCODE	1      /* include my extensions P.K., define always    */
 #define	IBMCHR	MSDOS  /* use IBM PC character set P.K.                */
 #define SCROLLCODE 1   /* scrolling code P.K.                          */
 
-/*	System dependant library redefinitions, structures and includes	*/
+/* System dependant library redefinitions, structures and includes. */
 
 #if TURBO
 #include <dos.h>
@@ -220,7 +207,7 @@
 #define	unlink(a)	delete(a)
 #endif
 
-/*	define some ability flags */
+/* Define some ability flags. */
 
 #if	IBMPC
 #define	MEMMAP	1
@@ -234,11 +221,11 @@
 #define	ENVFUNC	0
 #endif
 
-/*	Emacs global flag bit definitions (for gflags)	*/
+/* Emacs global flag bit definitions (for gflags). */
 
 #define	GFREAD	1
 
-/*	internal constants	*/
+/* Internal constants. */
 
 #define	NBINDS	256		/* max # of bound keys          */
 #define NFILEN  80		/* # of bytes, file name        */

eval.c

@@ -1,4 +1,4 @@
-/*	EVAL.C
+/*	eval.c
  *
  *	Expression evaluation functions
  *
@@ -12,19 +12,20 @@
 #include "efunc.h"
 #include "evar.h"
 #include "util.h"
+#include "version.h"
 
+/* Initialize the user variable list. */
 void varinit(void)
-{				/* initialize the user variable list */
+{
 	int i;
-
 	for (i = 0; i < MAXVARS; i++)
 		uv[i].u_name[0] = 0;
 }
 
 /*
- * evaluate a function
+ * Evaluate a function.
  *
- * char *fname;		name of function to evaluate
+ * @fname: name of function to evaluate.
  */
 char *gtfun(char *fname)
 {
@@ -259,7 +260,7 @@ char *gtenv(char *vname)
 	case EVVERSION:
 		return (VERSION);
 	case EVPROGNAME:
-		return (PROGNAME);
+		return (PROGRAM_NAME_LONG);
 	case EVSEED:
 		return (itoa(seed));
 	case EVDISINP:

main.c

@@ -60,6 +60,7 @@
 #include "edef.h"    /* Global definitions. */
 #include "efunc.h"   /* Function declarations and name table. */
 #include "ebind.h"   /* Default key bindings. */
+#include "version.h"
 
 /* For MSDOS, increase the default stack space. */
 #if MSDOS & TURBO
@@ -87,6 +88,16 @@ extern void sizesignal(int);
 #endif
 #endif
 
+void usage(int status)
+{
+  printf("Usage: %s filename\n", PROGRAM_NAME);
+  printf("   or: %s [options]\n\n", PROGRAM_NAME);
+  fputs("      --help     display this help and exit\n", stdout);
+  fputs("      --version  output version information and exit\n", stdout);
+
+  exit(status);
+}
+
 #if CALLED
 int emacs(int argc, char **argv)
 #else
@@ -117,11 +128,11 @@ int main(int argc, char **argv)
 	int newc;
 
 #if	PKCODE & VMS
-	(void) umask(-1);	/* use old protection (this is at wrong place) */
+	(void) umask(-1); /* Use old protection (this is at wrong place). */
 #endif
 
 #if	PKCODE & BSD
-	sleep(1);		/* time for window manager */
+	sleep(1); /* Time for window manager. */
 #endif
 
 #if	UNIX
@@ -130,13 +141,16 @@ int main(int argc, char **argv)
 #endif
 #endif
 	if (argc == 2) {
-		if (!strcmp(argv[1], "--version")) {
-			printf("%s version %s\n", PROGNAME, VERSION);
+		if (strcmp(argv[1], "--help") == 0) {
+			usage(EXIT_FAILURE);
+		}
+		if (strcmp(argv[1], "--version") == 0) {
+			printf("%s version %s\n", PROGRAM_NAME_LONG, VERSION);
 			exit(EXIT_SUCCESS);
 		}
 	}
 
-	/* initialize the editor */
+	/* Initialize the editor. */
 	vtinit();		/* Display */
 	edinit("main");		/* Buffers, windows */
 	varinit();		/* user variables */

version.h

@@ -0,0 +1,9 @@
+#ifndef VERSION_H_
+#define VERSION_H_
+
+#define PROGRAM_NAME "em"
+#define PROGRAM_NAME_LONG "uEmacs/Pk"
+
+#define	VERSION		"4.0.15"
+
+#endif  // VERSION_H_