Add -l option to enable command logging.

advent.txt

@@ -24,6 +24,10 @@ port of the 1976 ancestor of this game.  To avoid a name collision,
 this game builds as 'advent', reflecting the fact that the PDP-10
 on which it originally ran limited filenames to 6 characters.
 
+== OPTIONS ==
+
+-l:: Log commands to specified file.
+
 == ENVIRONMENT VARIABLES ==
 ADVENTURE::
    Path to the text database file describing Colossal Cave.

main.c

@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdbool.h>
+#include <getopt.h>
 #include "main.h"
 
 #include "misc.h"
@@ -39,6 +40,7 @@ long ABBNUM, ACTSPK[36], AMBER, ATTACK, AXE, BACK, BATTER, BEAR, BIRD, BLOOD, BO
 		 TRVSIZ = 885, TTEXT[6], TURNS, URN, V1, V2, VASE, VEND, VERB,
 		VOLCAN, VRBSIZ = 35, VRSION = 25, WATER, WD1, WD1X, WD2, WD2X,
 		WZDARK = false, ZZWORD;
+FILE  *logfp;
 
 extern void initialise();
 extern void score(long);
@@ -49,6 +51,7 @@ extern int action(long);
  */
 
 int main(int argc, char *argv[]) {
+	int ch;
 
 /*  Adventure (rev 2: 20 treasures) */
 
@@ -58,6 +61,20 @@ int main(int argc, char *argv[]) {
  *		Errata fixed: 78/12/25 */
 
 
+/*  Options. */
+
+	while ((ch = getopt(argc, argv, "l:")) != EOF) {
+		switch (ch) {
+		case 'l':
+			logfp = fopen(optarg, "w+");
+			if (logfp == NULL)
+				fprintf(stderr,
+					"advent: can't open logfile %s for write\n",
+					optarg);
+			break;
+		}
+	}
+
 /* Logical variables:
  *
  *  CLOSED says whether we're all the way closed
@@ -90,8 +107,6 @@ int main(int argc, char *argv[]) {
 	RSPEAK(201);
 	exit(0);
 
-
-
 /*  Start-up, dwarf stuff */
 
 L1:	SETUP= -1;

main.h

@@ -4,3 +4,4 @@ extern long ABB[], ATAB[], ATLOC[], BLKLIN, DFLAG, DLOC[], FIXED[], HOLDNG,
 		KTAB[], *LINES, LINK[], LNLENG, LNPOSN,
 		PARMS[], PLACE[], PTEXT[], RTEXT[], TABSIZ;
 extern signed char INLINE[LINESIZE+1], MAP1[], MAP2[];
+extern FILE *logfp;

misc.c

@@ -885,7 +885,12 @@ long I, VAL;
 	if(MAP2[1] == 0)MPINIT();
 
 	IGNORE(fgets(INLINE+1,sizeof(INLINE)-1,OPENED));
-	if (!feof(OPENED)) {
+	if (feof(OPENED)) {
+		if (logfp)
+			fclose(logfp);
+	} else {
+		if (logfp)
+			IGNORE(fputs(INLINE+1, logfp));
 		LNLENG=0;
 		for (I=1; I<=sizeof(INLINE) && INLINE[I]!=0; I++) {
 		VAL=INLINE[I]+1;