当错误发生时

Question

我使用的功能，读取和处理结构化的文件整理脚本/函数执行：

fname=strcat(folder,'\',fname); 
FID=fopen(fname); 
% reading lines and digging and procsesing data using fgetl() and regexp() 
fclose(FID); 

当有任何错误阅读和挖掘部分的错误信息被抛出，但该文件是打开并且FID指针丢失。大部分是由于缺失或错误线路造成的。

发生错误时如何避免丢失FID指针（用于手动关闭）和/或发生错误时执行fclose(FID)？ 或者有没有办法打开一个文件不锁定它？

Answer 1

也许使用try-catch块。事实上，你甚至都不需要catch这里：

fname = strcat(folder,'\',fname); %\\' 
FID = fopen(fname); 
try 
    %// reading lines and digging and procsesing data using fgetl() and regexp() 
    %// errors in this part are not shown 
end 
fclose(FID); %// this gets executed even if there were errors in reading and digging 

或者，如果你想显示错误：

fname = strcat(folder,'\',fname); %\\' 
FID = fopen(fname); 
try 
    %// reading lines and digging and procsesing data using fgetl() and regexp() 
catch 
    e = lasterror; 
    fprintf(2,'%s\n',e.message); %// show message in red 
end 
fclose(FID); %// this gets executed even if there were errors in reading and digging 

或显示错误，但首先关闭文件：

fname = strcat(folder,'\',fname); %\\' 
FID = fopen(fname); 
try 
    %// reading lines and digging and procsesing data using fgetl() and regexp() 
catch ME 
    fclose(FID); %// close file 
    error(ME.message) %// issue error 
end 
fclose(FID);