Add File Handling Exampler.

Open_Close_Read_Write/file_handling.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+
+int main(void){
+
+	int FLAG = O_RDONLY;
+	int file = open("/proc/cpuinfo", FLAG);
+	
+	int size = 1000;
+	char *buffer = malloc(size * sizeof(char));
+	if(read(file, buffer, size) == -1){
+		perror("read error");
+		free(buffer);
+		return -1;
+	}
+
+	char var_name[size];
+	char var_value[size];
+	sscanf(buffer, "%*s %*s %*s %s %*s %s", var_name, var_value);
+
+	printf("%s: %s\n", var_name, var_value);
+	
+	int FLAG2 = O_WRONLY;
+	int FLAG3 = O_CREAT;
+	int FLAG4 = O_APPEND;
+	int file2 = open("output.txt", FLAG2 | FLAG3 | FLAG4);
+	
+	char *msg = "Hallo Welt\n";
+		
+
+	if(write(file2, msg, strlen(msg)) == -1){
+		perror("write error");
+		return -1;
+	}
+
+
+	free(buffer);
+	close(file);
+	close(file2);	
+	return 0;
+}