comm: almost total rewrite; add testsuite

function                                             old     new   delta
writeline                                            128     125      -3
comm_main                                            540     239    -301
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-304)           Total: -304 bytes

1 files changed, 41 insertions, 54 deletions

diff --git a/coreutils/comm.c b/coreutils/comm.c
index b62c987..221cbfb 100644
--- a/coreutils/comm.c
+++ b/coreutils/comm.c
@@ -14,8 +14,9 @@
 #define COMM_OPT_3 (1 << 2)
 
 /* writeline outputs the input given, appropriately aligned according to class */
-static void writeline(char *line, int class, int flags)
+static void writeline(char *line, int class)
 {
+	int flags = option_mask32;
 	if (class == 0) {
 		if (flags & COMM_OPT_1)
 			return;
@@ -32,81 +33,67 @@ static void writeline(char *line, int class, int flags)
 		if (!(flags & COMM_OPT_2))
 			putchar('\t');
 	}
-	fputs(line, stdout);
+	puts(line);
 }
 
 int comm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int comm_main(int argc UNUSED_PARAM, char **argv)
 {
-#define LINE_LEN 100
-#define BB_EOF_0 0x1
-#define BB_EOF_1 0x2
-	char thisline[2][LINE_LEN];
-	FILE *streams[2];
+	char *thisline[2];
+	FILE *stream[2];
 	int i;
-	unsigned flags;
+	int order;
 
 	opt_complementary = "=2";
-	flags = getopt32(argv, "123");
+	getopt32(argv, "123");
 	argv += optind;
 
 	for (i = 0; i < 2; ++i) {
-		streams[i] = (argv[i][0] == '-' && !argv[i][1]) ? stdin : xfopen(argv[i], "r");
-		fgets(thisline[i], LINE_LEN, streams[i]);
+		stream[i] = xfopen_stdin(argv[i]);
 	}
 
-	/* This is the real core of the program - lines are compared here */
-
-	while (*thisline[0] || *thisline[1]) {
-		int order = 0;
-
-		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;
+	order = 0;
+	thisline[1] = thisline[0] = NULL;
+	while (1) {
+		if (order <= 0) {
+			free(thisline[0]);
+			thisline[0] = xmalloc_fgetline(stream[0]);
+		}
+		if (order >= 0) {
+			free(thisline[1]);
+			thisline[1] = xmalloc_fgetline(stream[1]);
 		}
 
-		if (order == 0 && !i)
-			writeline(thisline[1], 2, flags);
-		else if (order > 0 && !(i & BB_EOF_1))
-			writeline(thisline[1], 1, flags);
-		else if (order < 0 && !(i & BB_EOF_0))
-			writeline(thisline[0], 0, flags);
-
-		if (i & BB_EOF_0 & BB_EOF_1) {
+		i = !thisline[0] + (!thisline[1] << 1);
+		if (i)
 			break;
+		order = strcmp(thisline[0], thisline[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, flags);
-				fgets(thisline[i], LINE_LEN, streams[i]);
-			}
-			break;
+		if (order >= 0)
+			writeline(thisline[1], order ? 1 : 2);
+		else
+			writeline(thisline[0], 0);
+	}
 
-		} else {
-			if (order >= 0)
-				fgets(thisline[1], LINE_LEN, streams[1]);
-			if (order <= 0)
-				fgets(thisline[0], LINE_LEN, streams[0]);
+	/* EOF at least on one of the streams */
+	i &= 1;
+	if (thisline[i]) {
+		/* stream[i] is not at EOF yet */
+		/* we did not print thisline[i] yet */
+		char *p = thisline[i];
+		writeline(p, i);
+		while (1) {
+			free(p);
+			p = xmalloc_fgetline(stream[i]);
+			if (!p)
+				break;
+			writeline(p, i);
 		}
 	}
 
 	if (ENABLE_FEATURE_CLEAN_UP) {
-		fclose(streams[0]);
-		fclose(streams[1]);
+		fclose(stream[0]);
+		fclose(stream[1]);
 	}
 
 	return EXIT_SUCCESS;