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>

5 files changed, 98 insertions, 86 deletions

diff --git a/display.c b/display.c
index 75e6212..deb54a5 100644
--- a/display.c
+++ b/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
@@ -8,13 +8,14 @@
  *	modified by Petri Kutvonen
  */
 
-#include	<errno.h>
-#include        <stdio.h>
-#include	<stdarg.h>
-#include	<unistd.h>
-#include	"estruct.h"
-#include        "edef.h"
-#include        "efunc.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <unistd.h>
+#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, ": ");
diff --git a/estruct.h b/estruct.h
index aacc217..fc29944 100644
--- a/estruct.h
+++ b/estruct.h
@@ -21,58 +21,45 @@
 #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 */
+#define MSDOS 1 /* MS/PC DOS 3.1-4.0 with Turbo C 2.0 */
 #else
-#define	MSDOS	0
+#define	MSDOS 0
 #endif
 
 #if defined(BSD) || defined(sun) || defined(ultrix) || (defined(vax) && defined(unix)) || defined(ultrix) || defined(__osf__)
 #ifndef BSD
-#define BSD	1		/* Berkeley UNIX */
+#define BSD 1 /* Berkeley UNIX */
 #endif
 #else
-#define	BSD	0
+#define	BSD 0
 #endif
 
 #if defined(SVR4) || defined(__linux__)	/* ex. SunOS 5.3 */
-#define SVR4	1
-#define SYSV	1
+#define SVR4 1
+#define SYSV 1
 #undef BSD
 #endif
 
 #if defined(SYSV) || defined(u3b2) || defined(_AIX) || (defined(i386) && defined(unix)) || defined(__hpux)
-#define	USG	1		/* System V UNIX */
+#define	USG 1 /* System V UNIX */
 #else
-#define	USG	0
+#define	USG 0
 #endif
 
 #if defined(VMS) || (defined(vax) && ! defined(unix))
-#define VMS	1		/* VAX/VMS */
+#define VMS 1 /* VAX/VMS */
 #else
-#define VMS	0
+#define VMS 0
 #endif
 
-#define	V7	0		/* no more */
+#define	V7 0 /* No more. */
 
 #else
 
@@ -130,25 +117,25 @@
 #define	TERMCAP	UNIX
 #define	IBMPC	MSDOS
 
-#endif				/*autoconf */
+#endif /* Autoconf. */
 
 /*	Configuration options	*/
 
-#define CVMVAS  1		/* arguments to page forward/back in pages      */
-#define	CLRMSG	0		/* space clears the message line with no insert */
-#define	CFENCE	1		/* fench matching in CMODE                      */
-#define	TYPEAH	1		/* type ahead causes update to be skipped       */
-#define DEBUGM	1		/* $debug triggers macro debugging              */
-#define	VISMAC	0		/* update display during keyboard macros        */
-#define	CTRLZ	0		/* add a ^Z at end of files under MSDOS only    */
-#define ADDCR	0		/* ajout d'un CR en fin de chaque ligne (ST520) */
-#define	NBRACE	1		/* new style brace matching command             */
-#define	REVSTA	1		/* Status line appears in reverse video         */
+#define CVMVAS  1  /* arguments to page forward/back in pages      */
+#define	CLRMSG	0  /* space clears the message line with no insert */
+#define	CFENCE	1  /* fench matching in CMODE                      */
+#define	TYPEAH	1  /* type ahead causes update to be skipped       */
+#define DEBUGM	1  /* $debug triggers macro debugging              */
+#define	VISMAC	0  /* update display during keyboard macros        */
+#define	CTRLZ	0  /* add a ^Z at end of files under MSDOS only    */
+#define ADDCR	0  /* ajout d'un CR en fin de chaque ligne (ST520) */
+#define	NBRACE	1  /* new style brace matching command             */
+#define	REVSTA	1  /* Status line appears in reverse video         */
 
 #ifndef	AUTOCONF
 
-#define	COLOR	1		/* color commands and windows                   */
-#define	FILOCK	0		/* file locking under unix BSD 4.2              */
+#define	COLOR	1  /* color commands and windows                   */
+#define	FILOCK	0  /* file locking under unix BSD 4.2              */
 
 #else
 
@@ -159,43 +146,43 @@
 #define	FILOCK	BSD
 #endif
 
-#endif				/* autoconf */
+#endif /* Autoconf. */
 
-#define	ISRCH	1		/* Incremental searches like ITS EMACS          */
-#define	WORDPRO	1		/* Advanced word processing features            */
-#define	FNLABEL	0		/* function key label code [HP150]              */
-#define	APROP	1		/* Add code for Apropos command                 */
-#define	CRYPT	1		/* file encryption enabled?                     */
-#define MAGIC	1		/* include regular expression matching?         */
-#define	AEDIT	1		/* advanced editing options: en/detabbing       */
-#define	PROC	1		/* named procedures                             */
-#define	CLEAN	0		/* de-alloc memory on exit                      */
-#define	CALLED	0		/* is emacs a called subroutine? or stand alone */
+#define	ISRCH	1  /* Incremental searches like ITS EMACS          */
+#define	WORDPRO	1  /* Advanced word processing features            */
+#define	FNLABEL	0  /* function key label code [HP150]              */
+#define	APROP	1  /* Add code for Apropos command                 */
+#define	CRYPT	1  /* file encryption enabled?                     */
+#define MAGIC	1  /* include regular expression matching?         */
+#define	AEDIT	1  /* advanced editing options: en/detabbing       */
+#define	PROC	1  /* named procedures                             */
+#define	CLEAN	0  /* de-alloc memory on exit                      */
+#define	CALLED	0  /* is emacs a called subroutine? or stand alone */
 
-#define ASCII	1		/* always using ASCII char sequences for now    */
-#define EBCDIC	0		/* later IBM mainfraim versions will use EBCDIC */
+#define ASCII	1  /* always using ASCII char sequences for now    */
+#define EBCDIC	0  /* later IBM mainfraim versions will use EBCDIC */
 
 #ifndef	AUTOCONF
 
-#define	XONXOFF	0		/* don't disable XON-XOFF flow control P.K.     */
-#define	NATIONL	0		/* interprete [,],\,{,},| as characters P.K.    */
+#define	XONXOFF	0  /* don't disable XON-XOFF flow control P.K.     */
+#define	NATIONL	0  /* interprete [,],\,{,},| as characters P.K.    */
 
 #else
 
 #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.                          */
+#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>
-#include      <mem.h>
+#if TURBO
+#include <dos.h>
+#include <mem.h>
 #undef peek
 #undef poke
 #define       peek(a,b,c,d)   movedata(a,b,FP_SEG(c),FP_OFF(c),d)
@@ -208,7 +195,7 @@
 #define	getname	xgetname
 #endif
 
-#if	MSDOS & MSC
+#if MSDOS & MSC
 #include	<dos.h>
 #include	<memory.h>
 #define	peek(a,b,c,d)	movedata(a,b,FP_SEG(c),FP_OFF(c),d)
@@ -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        */
diff --git a/eval.c b/eval.c
index 269b4d2..8d685f2 100644
--- a/eval.c
+++ b/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:
diff --git a/main.c b/main.c
index 873fbf8..24ee40a 100644
--- a/main.c
+++ b/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 */
diff --git a/version.h b/version.h
new file mode 100644
index 0000000..5f9c6ff
--- /dev/null
+++ b/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_