#ifndef LOG_H
#define LOG_H

#include <time.h>

typedef struct data_struct {
    time_t time;
    char *string;
} data_t;

int addmsg(data_t data);
void clearlog(void);
char *getlog(void);
int savelog(char *filename);

#endif

#ifndef LOG_H
#define LOG_H

#include <time.h>

typedef struct data_struct {
    time_t time;
    char *string;
} data_t;

int addmsg(data_t data);
void clearlog(void);
char *getlog(void);
int savelog(const char *filename);

#endif

Make the char * parameter as const char *
Make the char * parameter as const char *
