2019-11-08 in class

midterm/processes/processes.c

@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include <stdlib.h>
 #include "processes.h"
 
@@ -10,7 +11,7 @@ struct process {
 	uint pid;
 	uint ppid;
 	char user[9];
-	double priority;
+	float priority;
 	ulong resident_size;
 	ulong size;
 	ulong virtual_size;
@@ -20,24 +21,56 @@ struct process {
 struct processes {
 	ulong size;
 	ulong capacity;
-	struct process procs[];
+	struct process* procs;
 };
 
 struct processes* new_processes() {
-	struct processes* p = malloc(sizeof(struct processes) + INIT_CAP *
-			sizeof(struct process));
+	struct processes* p = malloc(sizeof(struct processes));
 	if (!p) {
 		return NULL;
 	}
 
+	struct process* p_arr = malloc(INIT_CAP * sizeof(struct process));
+	if (!p_arr) {
+		free(p);
+		return NULL;
+	}
+
 	p->size = 0;
 	p->capacity = INIT_CAP;
+	p->procs = p_arr;
 	return p;
 }
 
 void delete(struct processes* p) {
+	free(p->procs);
 	free(p);
 }
 
+int add_from_file(struct processes* ps, const char* filename) {
+	FILE* f = fopen(filename, "r");
+	if (!f) {
+		return 0;
+	}
+
+	struct process p;
+	while (fscanf(f, "%u %u %8s %f %lu %lu %lu %15s\n", &p.pid, &p.ppid,
+			p.user, &p.priority,&p.resident_size, &p.size,
+			&p.virtual_size, p.command) == 8) {
+
+		if (ps->size == ps->capacity) {
+			ps->capacity *= 2;
+			struct process* new_procs = realloc(ps->procs,
+				ps->capacity * sizeof(struct process));
+			if (!new_procs) {
+				return 0;
+			}
+			ps->procs = new_procs;
+		}
+
+		ps->procs[ps->size] = p;
+		ps->size++;
+	}
+}