How to read a text file into a char array

This is probably trivial, but I have not found an easy way to convert a text file of n lines and m columns (sample attached) into a char array of the same shape. The only way that might work for me is an n-long for-loop of "fscanf", but I do not know n beforehand, and I figure there must be a simpler and faster vectorized command, which I ignore (I tried fileread and textread to no avail).

Answer 1

[Walter Roberson]

temp = regexp(fileread('sample_input.txt'), '\r?\n', 'split');
output = vertcat(temp{:});

[Paolo Binetti]

Good that I asked, my several attempts were way off! One question: what is the purpose of "?" ? I have tried without, and it also works.

[Walter Roberson]

The \r represents carriage return. I did not bother to check whether your file has those or only newlines (and it is really easy end up accidentally having a mix of files) so I made the carriage return optional which is done by adding a ? after it.

An alternative to the \r?\n for your situation would be \W+ which would mean any sequence of consecutive non-"word" characters. That would also cover the case where you had multiple columns separated by blanks that you wanted to treat the same as if each were its own line.

[Paolo Binetti]

Thank you, clear and useful.