From 2088ea284e15ec42a475ea8a0841e2579cd9c937 Mon Sep 17 00:00:00 2001
From: Mitja Felicijan <mitja.felicijan@gmail.com>
Date: Sat, 22 Jun 2024 19:57:42 +0200
Subject: New note: Read, write structs

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 ...4-06-22-write-and-read-structs-to-files-in-c.md | 81 ++++++++++++++++++++++
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diff --git a/content/notes/2024-06-22-write-and-read-structs-to-files-in-c.md b/content/notes/2024-06-22-write-and-read-structs-to-files-in-c.md
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+---
+title: "Write and read structs to/from files in C"
+url: write-and-read-structs-to-files-in-c.html
+date: 2024-06-22T16:13:13+02:00
+type: note
+draft: false
+tags: [c]
+---
+
+First let's define a shared header file for the struct definition.
+
+```c
+// struct.h
+typedef struct {
+    char name[50];
+    int health;
+    float damage;
+} Character;
+```
+
+Now lets write it to a `character.dat` file.
+
+```c
+// write.c
+#include <stdio.h>
+#include <string.h>
+
+#include "struct.h"
+
+int main(void) {
+    printf("Write struct\n");
+
+    Character ch;
+
+    strcpy(ch.name, "John Doe");
+    ch.health = 30;
+    ch.damage = 5.9;
+
+    FILE* file = fopen("character.dat", "wb");
+    if (file == NULL) {
+        perror("Error opening file");
+        return 1;
+    }
+
+    fwrite(&ch, sizeof(Character), 1, file);
+    fclose(file);
+
+    return 0;
+}
+```
+
+And reading and serializing back to a struct.
+
+```c
+// read.c
+#include <stdio.h>
+
+#include "struct.h"
+
+int main(void) {
+    printf("Read struct\n");
+
+    Character ch;
+
+    FILE* file = fopen("character.dat", "rb");
+    if (file == NULL) {
+        perror("Error opening file");
+        return 1;
+    }
+
+    fread(&ch, sizeof(Character), 1, file);
+    fclose(file);
+
+    printf("Name: %s\n", ch.name);
+    printf("Health: %d\n", ch.health);
+    printf("Damage: %.1f\n", ch.damage);
+
+    return 0;
+}
+```
+
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