From 16aeaf6c379f10caa690a3ecb9d11674e4770bce Mon Sep 17 00:00:00 2001
From: Ivaylo Ivanov <me@ivayloivanov.eu>
Date: Sun, 16 Dec 2018 17:58:23 +0100
Subject: [PATCH] Refactor string building and fix reader

---
 cpair/cpair.c | 69 +++++++++++++--------------------------------------
 1 file changed, 17 insertions(+), 52 deletions(-)

diff --git a/cpair/cpair.c b/cpair/cpair.c
index 4ef5384..4c26110 100644
--- a/cpair/cpair.c
+++ b/cpair/cpair.c
@@ -81,7 +81,8 @@ int main(int argc, char *argv[]) {
         exit(EXIT_FAILURE);
     }
 
-    char input[__UINT8_MAX__] = ""; ///< An array to save the input to
+    char * input = ""; ///< An array to save the input to
+    size_t input_len;
     int point_num = 0; ///< Save the number of points
     node_t * head = NULL;
 
@@ -89,7 +90,8 @@ int main(int argc, char *argv[]) {
 
     node_t * current = head;
 
-    while(fgets(input, __INT8_MAX__, stdin) != NULL) { ///< Read line by line
+    while(getline(&input, &input_len, stdin) > 0) { ///< Read line by line
+        fprintf(stderr, "pid: %d \n%s\n", getpid(), input);
         /// Split the input by whitespace as delimiter
         char *x = strtok(input, " ");
         char *y = strtok(NULL, " ");
@@ -107,11 +109,6 @@ int main(int argc, char *argv[]) {
         }
     }
 
-    if(feof(stdin) == 0) {
-        fprintf(stderr, "ERROR: An error interrupted the read\n");
-        exit(EXIT_FAILURE);
-    }
-
     if(point_num == 1)
         exit(EXIT_SUCCESS);
 
@@ -169,30 +166,22 @@ int main(int argc, char *argv[]) {
 
                     float x_mean = get_x_mean(head);
 
-                    node_t * first_part = malloc(sizeof(node_t));
-                    int first_part_len = 1;
-
-                    node_t * second_part = malloc(sizeof(node_t));
-                    int second_part_len = 1;
-
-                    node_t * first_part_buff = first_part;
-                    node_t * second_part_buff = second_part;
-
                     /// Separate the lists based on the mean
                     current = head;
+
+                    char * first_part = malloc(point_num * __UINT8_MAX__);
+                    char * second_part = malloc(point_num * __UINT8_MAX__);
+
                     while(current -> next != NULL) {
+                        char point[__UINT8_MAX__];
                         if(current -> points[0] <= x_mean) {
-                            first_part_buff -> points[0] = current -> points[0];
-                            first_part_buff -> points[1] = current -> points[1];
-                            first_part_buff -> next = malloc(sizeof(node_t));
-                            first_part_buff = first_part_buff -> next;
-                            first_part_len ++;
+                            /// Setup string for first child pipe
+                            sprintf(point, "%f %f\n", current -> points[0], current -> points[1]);
+                            strcat(first_part, point);
                         } else {
-                            second_part_buff -> points[0] = current -> points[0];
-                            second_part_buff -> points[1] = current -> points[1];
-                            second_part_buff -> next = malloc(sizeof(node_t));
-                            second_part_buff = second_part_buff -> next;
-                            second_part_len ++;
+                            /// Setup string for second child pipe
+                            sprintf(point, "%f %f\n", current -> points[0], current -> points[1]);
+                            strcat(second_part, point);
                         }
                         current = current -> next;
                     }
@@ -202,24 +191,13 @@ int main(int argc, char *argv[]) {
                      * Send first half to first child
                      *
                      **/
-                    /// Setup string for first child pipe
-                    current = first_part;
-                    char first_part_string[first_part_len][__UINT8_MAX__];
-                    int i = 0;
-                    while(current -> next != NULL) {
-                        sprintf(first_part_string[i], "%f %f\n", current -> points[0], current -> points[1]);
-                        i++;
-                        current = current -> next;
-                    }
-                    first_part_string[first_part_len][0] = EOF;
-
                     if(dup2(in_pipe_a[1], STDIN_FILENO) != STDIN_FILENO) {
                         fprintf(stderr, "ERROR: Failed duplicating STDIN\n");
                         exit(EXIT_FAILURE);
                     }
 
                     /// Write to pipe
-                    if (write(in_pipe_a[1], first_part_string, first_part_len * __UINT8_MAX__) < 0) {
+                    if (write(in_pipe_a[1], first_part, strlen(first_part)) < 0) {
                         fprintf(stderr, "ERROR: Failed writing to child\n");
                         exit(EXIT_FAILURE);
                     }
@@ -230,24 +208,13 @@ int main(int argc, char *argv[]) {
                      * Send second half to second child
                      *
                      **/
-                    /// Setup string for second child pipe
-                    current = second_part;
-                    char second_part_string[second_part_len + 1][__UINT8_MAX__];
-                    i = 0;
-                    while(current -> next != NULL) {
-                        sprintf(second_part_string[i], "%f %f\n", current -> points[0], current -> points[1]);
-                        i++;
-                        current = current -> next;
-                    }
-                    second_part_string[second_part_len][0] = EOF;
-
                     if(dup2(in_pipe_b[1], STDIN_FILENO) != STDIN_FILENO) {
                         fprintf(stderr, "ERROR: Failed duplicating STDIN\n");
                         exit(EXIT_FAILURE);
                     }
 
                     /// Write to pipe
-                    if (write(in_pipe_b[1], second_part_string, second_part_len * __UINT8_MAX__) < 0) {
+                    if (write(in_pipe_b[1], second_part, strlen(second_part)) < 0) {
                         fprintf(stderr, "ERROR: Failed writing to child\n");
                         exit(EXIT_FAILURE);
                     }
@@ -262,9 +229,7 @@ int main(int argc, char *argv[]) {
                     /// Free the memory
                     free(head);
                     free(first_part);
-                    free(first_part_buff);
                     free(second_part);
-                    free(second_part_buff);
                     free(current);
                     break;
             }