linux下c语言计算md5

s8* get_file_md5(s8 *file)
{
    s8 cmd[256] = {0};
    static s8 md5[128] = {0};
    FILE *fp = NULL;

    snprintf(cmd, 255, "md5sum %s |awk '{print $1}'", file);
    fp = fopen(cmd, "r");

    if(fp)
    {
        fgets(md5, 64, fp);

        fclose(fp);
        fp = NULL;

        return md5;
    }
    else
    {
        return -1;
    }
}