update the text file

Question

raviranjan singh 2018-5-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/403154-update-the-text-file

评论： Walter Roberson 2018-5-30

i have only call the number from text file in edit text and if the number is change, it must be update at the give place in same text. there is any code to update the change value in same text after clicking the push bottom for given edit text box.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2018-5-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/403154-update-the-text-file#answer_322468

Updating text files is not recommended. It is only possible if the replacement is exactly the same size as the original text.

It is recommended that instead you write a new text file with the new content, and that you do not get rid of the old file until you are certain that the new one is correct.

2 个评论
显示无隐藏无

raviranjan singh 2018-5-30

in my text file both number and sentence is there and i changes only number, than what i can do?

Walter Roberson 2018-5-30

You can read from the old file, copying to a new file, except for the values you want changed, where you would write out the new value instead.

There is no possibility to just update part of a text file, except in the case where the new text is exactly the same size as the old text. This is not a MATLAB limitation: it is a fundamental restriction on all programs due to the way that text files are stored.

(Historically, there were a couple of operating systems that permitted text files to be stored in a way that permitted them to be updated, but the simplicity and efficiency of the current way of storing files won out in the early 80s.)

请先登录，再进行评论。