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 b62c98772..221cbfbcc 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;