How to read input.txt?

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Yasuyuki Hamanaka
Yasuyuki Hamanaka on 24 Aug 2021
Commented: Walter Roberson on 25 Aug 2021
Would you tell me how to read .txt file like below.
I would like to read first two lines as string and other lines as real.
I tried to use fscanf though, it doesn't work well.
Thank you.
Stephen23 on 24 Aug 2021
@Yasuyuki Hamanaka: what integer do you expect the characters 'aaaaaa' to return ?

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Accepted Answer

Walter Roberson
Walter Roberson on 24 Aug 2021
fid = fopen('input.txt');
textlines{1} = fgetl(fid);
textlines{2} = fgetl(fid);
numbers = cell2mat(textscan(fid, '%f'));
Walter Roberson
Walter Roberson on 25 Aug 2021
For future reference:
There is also the closely related function fgets() . The difference between fgetl() and fgets() is that fgetl() strips the line terminators off, but fgets() leaves them in.
So when the purpose is to copy a file, then fgets() is better because it includes the original line terminators in -- if the original line terminator was CR+LF then the CR+LF will both be present for fgets() and will make it into any file that you write them to fgetl() would remove the CR+LF, so fgetl() is better for the case where you are analyzing the content and don't want to have to worry all the time about whether the original had CR+LF or LF alone.

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More Answers (1)

dpb on 24 Aug 2021
Are the string data pertinent or just in the way of returning the numeric data?
If the former, while you can make it work with low-level i/o such as fprintf, it's the hard way to go at it -- use
readcell instead.
If the latter and the text is (say) a header line and units or similar, use readtable




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