fopen：文件打开
fclose：文件关闭
fread：二进制数据的读取
fwrite：二进制文件写入
fgetl：逐行读取
fgets：逐行读取
fscanf：格式化读取：
fprintf：格式化写入 
clear all;
[fid,message]=fopen('file2.txt','w+');
if fid==-1
    disp(message);
else
    fwrite(fid,'good moring','uint8');
end
fclose(fid);
[fid,message]=fopen('file2.txt','r');
if fid==-1
    disp(message);
else
    a1=fread(fid);
    a1'
    disp(char(a1)');
end
fclose(fid); 

clear all;
[fid,message]=fopen('file3.txt','w+');
if fid==-1
    disp(message);
else
    magic(4)
    fwrite(fid,magic(4),'int32');
end
fclose(fid);
[fid,message]=fopen('file3.txt','r');
if fid==-1
    disp(message);
else
    a1=fread(fid,[3 3],'int32');
    a1
end
fclose(fid);