remove duplicated code and rework algorithms to end up with smaller code

1 files 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);
-
-                if (feof(streams[0]) && feof(streams[1])) {
-                        fclose(streams[0]);
-                        fclose(streams[1]);
-                        break;
+                else if (order > 0 && !(i & BB_EOF_1))
+                        writeline(thisline[1], 1);
+                else if (order < 0 && !(i & BB_EOF_0))
+                        writeline(thisline[0], 0);
 
-                } else if (feof(streams[0])) {
-                        while (!feof(streams[1])) {
-                                if (order < 0)
-                                        writeline(thisline[1], 2);
-                                fgets(thisline[1], 100, streams[1]);
-                        }
-                        fclose(streams[0]);
-                        fclose(streams[1]);
+                if (i & BB_EOF_0 & BB_EOF_1) {
                         break;
 
-                } else if (feof(streams[1])) {
-                        while (!feof(streams[0])) {
-                                if (order > 0)
-                                        writeline(thisline[0], 1);
-                                fgets(thisline[0], 100, streams[0]);
+                } 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 (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);
 }