scramble

commit ed9fac767d26938b2797cfeaef33687816837d3c
parent 590cd3a6d2359734ec4775c9d1e8b431514e732b
Author: Nihal Jere <noocsharp@gmail.com>
Date:   Wed, 29 Jan 2020 23:34:05 -0600

renamed main.c, removed unnecessary calloc, made help work

Diffstat:
M
Makefile
 | 
2
+-
D
main.c
 | 
88
-------------------------------------------------------------------------------
A
scramble.c
 | 
84
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 85 insertions(+), 89 deletions(-)
diff --git a/Makefile b/Makefile
@@ -2,7 +2,7 @@ PREFIX = /usr/local
 CC = cc
 
 all:
-	${CC} main.c -o scramble
+	${CC} scramble.c -o scramble
 
 clean:
 	rm -f scramble
diff --git a/main.c b/main.c
@@ -1,88 +0,0 @@
-#include <stdlib.h>
-#include <time.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <sys/random.h>
-
-#define DEFAULT_LENGTH 25
-
-static const char* pmoves[3][6] = { {"U", "D", "L", "R", "F", "B"}, {"U'", "D'", "L'", "R'", "F'", "B'"}, {"U2", "D2", "L2", "R2", "F2", "B2"} };
-
-const char help[] = "usage: scramble [LENGTH]";
-
-static char const** typo_scramble(uint8_t length) {
-    char const** moves = calloc(length, sizeof(char*));
-
-    if (moves == NULL) return NULL;
-
-    uint8_t last_side = 0;
-
-    uint8_t counter = 0;
-    // TODO deal with RAND_MAX
-    while (counter < length) {
-        uint8_t rval = (uint8_t) rand();
-        // 3 possible values for set, so 2 bits
-        uint8_t set = rval & 3;
-        // 6 possible values for side, so 3 bits
-        uint8_t side = (rval >> 2) & 7;
-
-        // prevent biasing of results that would occur if
-        // we just took the modulus of the values
-        if (set == 3 || side > 5) continue;
-
-        // if the side is the same as before, choose another side
-        if (counter != 0 && side == last_side) continue;
-
-        moves[counter++] = pmoves[set][side];
-        last_side = side;
-    }
-
-    return moves;
-}
-
-int main(int argc, char** argv) {
-    uint8_t length = DEFAULT_LENGTH;
-
-    if (argc > 2) {
-        printf("%s: Too many arguments\n", argv[0]);
-        return -1;
-    } else if (argc == 2) {
-        if (argv[1] == "-h" || argv[1] == "--help") {
-            printf("%s\n", help);
-            return 0;
-        }
-
-        char* endptr = NULL;
-        long int newlength = strtol(argv[1], &endptr, 10);
-
-        if (*endptr != '\0') {
-            printf("%s: invalid length\n", argv[0]);
-            return -2;
-        }
-
-        if (0 > newlength || newlength > 255) {
-            printf("%s: invalid length, max of 255\n", argv[0]);
-            return -3;
-        }
-
-        length = newlength;
-    }
-
-    uint32_t seed = 0;
-    getrandom((void*) &seed, 4, GRND_NONBLOCK);
-    srand(seed);
-
-    const char** moves;
-
-    
-    if ((moves = typo_scramble(length)) != NULL) {
-        for (uint8_t i = 0; i < length; ++i) {
-            printf("%s ", moves[i]);
-        }
-        printf("\n");
-        free(moves);
-    }
-
-    return 0;
-
-}
diff --git a/scramble.c b/scramble.c
@@ -0,0 +1,84 @@
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/random.h>
+
+#define DEFAULT_LENGTH 25
+
+static const char* pmoves[3][6] = { {"U", "D", "L", "R", "F", "B"}, {"U'", "D'", "L'", "R'", "F'", "B'"}, {"U2", "D2", "L2", "R2", "F2", "B2"} };
+
+const char help[] = "usage: scramble [LENGTH]";
+
+static int typo_scramble(const char** moves, uint8_t length) {
+
+    uint8_t last_side = 0;
+
+    uint8_t counter = 0;
+    // TODO deal with RAND_MAX
+    while (counter < length) {
+        uint8_t rval = (uint8_t) rand();
+        // 3 possible values for set, so 2 bits
+        uint8_t set = rval & 3;
+        // 6 possible values for side, so 3 bits
+        uint8_t side = (rval >> 2) & 7;
+
+        // prevent biasing of results that would occur if
+        // we just took the modulus of the values
+        if (set == 3 || side > 5) continue;
+
+        // if the side is the same as before, choose another side
+        if (counter != 0 && side == last_side) continue;
+
+        moves[counter++] = pmoves[set][side];
+        last_side = side;
+    }
+
+    return 0;
+}
+
+int main(int argc, char** argv) {
+    uint8_t length = DEFAULT_LENGTH;
+
+    if (argc > 2) {
+        printf("%s: Too many arguments\n", argv[0]);
+        return -1;
+    } else if (argc == 2) {
+        if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--help") == 0) {
+            printf("%s\n", help);
+            return 0;
+        }
+
+        char* endptr = NULL;
+        long int newlength = strtol(argv[1], &endptr, 10);
+
+        if (*endptr != '\0') {
+            printf("%s: invalid length\n", argv[0]);
+            return -2;
+        }
+
+        if (0 > newlength || newlength > 255) {
+            printf("%s: invalid length, max of 255\n", argv[0]);
+            return -3;
+        }
+
+        length = newlength;
+    }
+
+    uint32_t seed = 0;
+    getrandom((void*) &seed, 4, GRND_NONBLOCK);
+    srand(seed);
+
+    const char* moves[length];
+    
+    if (typo_scramble(moves, length) == 0) {
+        for (uint8_t i = 0; i < length; ++i) {
+            printf("%s ", moves[i]);
+        }
+        printf("\n");
+    }
+
+    return 0;
+
+}