发生错误时完成 script/function 执行

Question

我正在使用读取和处理结构化文件的功能：

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

当 读取和挖掘 部分出现任何错误时，会抛出一条错误消息，但文件会打开并且 FID 指针会丢失。多半是漏线或错线造成的。

发生错误时如何避免丢失FID指针（用于手动关闭）and/or发生错误时执行fclose(FID)？或者有没有办法打开文件而不锁定它？

Answer 1

也许使用 try-catch 块。事实上，你甚至不需要这里的 catch：

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，如果您想显示错误：

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);

发生错误时完成 script/function 执行

Finishing script/function execution when error occurs

matlab

error-handling

fopen