updated file database added get_all_users get_user_by_id

get_user_by_username get_user_field_by_id

src/file.c

@@ -2,6 +2,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 char *read_file(const char *path) {
   FILE *fp = fopen(path, "rb");
@@ -14,7 +15,7 @@ char *read_file(const char *path) {
   long file_size = ftell(fp);
   rewind(fp);
 
-  char *buffer = (char *)malloc(file_size + 1);
+  char *buffer = (char *) malloc(file_size + 1);
   if (!buffer) {
     perror("Error allocating memory");
     fclose(fp);
@@ -32,4 +33,20 @@ char *read_file(const char *path) {
   buffer[file_size] = '\0';
   fclose(fp);
   return buffer;
-}
+}
+
+char *write_file(const char *path, const char *data) {
+  FILE *fp = fopen(path, "w");
+  if (fp == NULL) {
+    printf("%s\n", path);
+    perror("Error opening file");
+    return nullptr;
+  }
+  if (fprintf(fp, "%s", data) < 0) {
+    perror("Error write file");
+    return nullptr;
+  }
+  fclose(fp);
+  char *ret = strdup(data);
+  return ret;
+}