linux c 增量备份

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <time.h>

#define SOURCE_DIR "/path/to/source"
#define BACKUP_DIR "/path/to/backup"
#define TIMESTAMP_FILE "/path/to/last_backup_timestamp.txt"

void backup_file(const char *source, const char *backup) {
    // 实现文件复制功能
    // ...
}

int is_file_modified(const char *file, time_t last_backup_time) {
    struct stat file_stats;
    if (stat(file, &file_stats) == 0) {
        return difftime(file_stats.st_mtime, last_backup_time) > 0;
    }
    return 0;
}

int main() {
    FILE *timestamp_file = fopen(TIMESTAMP_FILE, "r");
    time_t last_backup_time = 0;
    if (timestamp_file) {
        fscanf(timestamp_file, "%ld", &last_backup_time);
        fclose(timestamp_file);
    }

    DIR *dir = opendir(SOURCE_DIR);
    struct dirent *entry;
    while ((entry = readdir(dir)) != NULL) {
        if (entry->d_type == DT_REG) {
            char source_file[1024];
            snprintf(source_file, sizeof(source_file), "%s/%s", SOURCE_DIR, entry->d_name);
            if (is_file_modified(source_file, last_backup_time)) {
                char backup_file[1024];
                snprintf(backup_file, sizeof(backup_file), "%s/%s", BACKUP_DIR, entry->d_name);
                backup_file(source_file, backup_file);
            }
        }
    }
    closedir(dir);

    timestamp_file = fopen(TIMESTAMP_FILE, "w");
    time_t current_time = time(NULL);
    fprintf(timestamp_file, "%ld", current_time);
    fclose(timestamp_file);

    return 0;
}