From 867a6080fe48b8d23c3845dcb875ba969eeee066 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Fri, 13 May 2005 00:57:30 +0000
Subject: [PATCH] remove duplicated code and rework algorithms to end up with
 smaller code

---
 coreutils/comm.c | 78 +++++++++++++++++++++++-------------------------
 1 file changed, 38 insertions(+), 40 deletions(-)

diff --git a/coreutils/comm.c b/coreutils/comm.c
index b0384fe87..7471c3b31 100644
--- a/coreutils/comm.c
+++ b/coreutils/comm.c
@@ -40,15 +40,16 @@ static int both;
 /* writeline outputs the input given, appropriately aligned according to class */
 static void writeline(char *line, int class)
 {
-	if (class == 1 && !only_file_1)
+	if (class == 0) {
+		if (!only_file_1)
 		return;
-	else if (class == 2) {
+	} else if (class == 1) {
 		if (!only_file_2)
 			return;
 		if (only_file_1)
 			putchar('\t');
 	}
-	else if (class == 3) {
+	else /*if (class == 2)*/ {
 		if (!both)
 			return;
 		if (only_file_1)
@@ -60,73 +61,69 @@ static void writeline(char *line, int class)
 }
 
 /* This is the real core of the program - lines are compared here */
-static int cmp_files(char **infiles)
+static void cmp_files(char **infiles)
 {
-	char thisline[2][100];
+#define LINE_LEN 100
+#define BB_EOF_0 0x1
+#define BB_EOF_1 0x2
+	char thisline[2][LINE_LEN];
 	FILE *streams[2];
-	int i = 0;
+	int i;
 
-	for (i = 0; i < 2; i++) {
-		streams[i] = (strcmp(infiles[i], "=") == 0 ? stdin : bb_xfopen(infiles[i], "r"));
-		fgets(thisline[i], 100, streams[i]);
+	for (i = 0; i < 2; ++i) {
+		streams[i] = ((infiles[i][0] == '=' && infiles[1][1]) ? stdin : bb_xfopen(infiles[i], "r"));
+		fgets(thisline[i], LINE_LEN, streams[i]);
 	}
 
 	while (thisline[0] || thisline[1]) {
 		int order = 0;
-		int tl0_len = strlen(thisline[0]);
-		int tl1_len = strlen(thisline[1]);
+
+		i = 0;
+		if (feof(streams[0])) i |= BB_EOF_0;
+		if (feof(streams[1])) i |= BB_EOF_1;
 
 		if (!thisline[0])
 			order = 1;
 		else if (!thisline[1])
 			order = -1;
 		else {
+			int tl0_len, tl1_len;
+			tl0_len = strlen(thisline[0]);
+			tl1_len = strlen(thisline[1]);
 			order = memcmp(thisline[0], thisline[1], tl0_len < tl1_len ? tl0_len : tl1_len);
 			if (!order)
 				order = tl0_len < tl1_len ? -1 : tl0_len != tl1_len;
 		}
 
-		if ((order == 0) && (!feof(streams[0])) && (!feof(streams[1])))
-			writeline(thisline[1], 3);
-		else if ((order > 0) && (!feof(streams[1])))
+		if (order == 0 && !i)
 			writeline(thisline[1], 2);
-		else if ((order < 0) && (!feof(streams[0])))
-			writeline(thisline[0], 1);
+		else if (order > 0 && !(i & BB_EOF_1))
+			writeline(thisline[1], 1);
+		else if (order < 0 && !(i & BB_EOF_0))
+			writeline(thisline[0], 0);
 
-		if (feof(streams[0]) && feof(streams[1])) {
-			fclose(streams[0]);
-			fclose(streams[1]);
+		if (i & BB_EOF_0 & BB_EOF_1) {
 			break;
 
-		} else if (feof(streams[0])) {
-			while (!feof(streams[1])) {
-				if (order < 0)
-					writeline(thisline[1], 2);
-				fgets(thisline[1], 100, streams[1]);
+		} else if (i) {
+			i = (i & BB_EOF_0 ? 1 : 0);
+			while (!feof(streams[i])) {
+				if ((order < 0 && i) || (order > 0 && !i))
+					writeline(thisline[i], i);
+				fgets(thisline[i], LINE_LEN, streams[i]);
 			}
-			fclose(streams[0]);
-			fclose(streams[1]);
-			break;
-
-		} else if (feof(streams[1])) {
-			while (!feof(streams[0])) {
-				if (order > 0)
-					writeline(thisline[0], 1);
-				fgets(thisline[0], 100, streams[0]);
-			}
-			fclose(streams[0]);
-			fclose(streams[1]);
 			break;
 
 		} else {
 			if (order >= 0)
-				fgets(thisline[1], 100, streams[1]);
+				fgets(thisline[1], LINE_LEN, streams[1]);
 			if (order <= 0)
-				fgets(thisline[0], 100, streams[0]);
+				fgets(thisline[0], LINE_LEN, streams[0]);
 		}
 	}
 
-	return 0;
+	fclose(streams[0]);
+	fclose(streams[1]);
 }
 
 int comm_main(int argc, char **argv)
@@ -142,5 +139,6 @@ int comm_main(int argc, char **argv)
 	only_file_2 = !(flags & COMM_OPT_2);
 	both = !(flags & COMM_OPT_3);
 
-	exit(cmp_files(argv + optind) == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+	cmp_files(argv + optind);
+	exit(EXIT_SUCCESS);
 }