How to do a loop in a text file until an empty line is found

29 views (last 30 days)
Hello,
I would like to open an external text file and do a loop that scans all the lines of the text file until an empty line is found. I know how to code what I would like to do, but I am not sure how I can replace my "For" cycle by a "While" cycle. Could someone help?
I thank you in advance,
Best regards,
Hugo

Accepted Answer

Cris LaPierre
Cris LaPierre on 3 Nov 2020
Edited: Cris LaPierre on 3 Nov 2020
Look at the example on the documentation page for fgetl. Assuming you are doing this in a loop (for or while, doesn't matter), you can use the break command to stop if the result of fgetl is empty.

More Answers (1)

Image Analyst
Image Analyst on 4 Nov 2020
Try this:
% Open the file for reading in text mode.
fileID = fopen(fullFileName, 'rt');
% Read the first line of the file.
textLine = fgetl(fileID);
lineCounter = 1;
while ischar(textLine)
% Print out what line we're operating on.
fprintf('%s\n', textLine);
% Read the next line.
textLine = fgetl(fileID);
if length(textLine) == 0
break;
end
lineCounter = lineCounter + 1;
end
% All done reading all lines, so close the file.
fclose(fileID);
You might also want to look at strtrim() to handle lines that have nothing but spaces on them. Not sure if you want to break on a line that was a space or not.

Categories

Find more on Entering Commands in Help Center and File Exchange

Tags

Products


Release

R2018b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!