How to append a text file to another text file

I have two files : file1.dat ans file2.dat and I want to add the content of the file2.dat to the end of file1.dat with a space between them like this :

How can I do this ?

Answer 1

[Stephen23]

Assuming no trailing newline characters in the files, perhaps one of these:

Append to existing file:

st2 = fileread('file2.dat');
[fid,msg] = fopen('file1.dat','at');
assert(fid>=3,msg)
fprintf(fid,'\n\n%s',st2);
fclose(fid);

Create a new file:

st1 = fileread('file1.dat');
st2 = fileread('file2.dat');
[fid,msg] = fopen('newfile.dat','wt');
assert(fid>=3,msg)
fprintf(fid,'%s\n\n%s',st1,st2);
fclose(fid);

[Izem]

Thank you so much! It worked. What is te utility of this line 'assert(fid>=3,msg)'?

[Stephen23]

" What is te utility of this line 'assert(fid>=3,msg)'?"

Gives more detailed information (the second output from fopen) in the event that a file cannot be opened, otherwise you will just get a message telling you that the file ID is not valid. The message tells you why.

[Izem]

Alright! Thanks again .

[Rafael Rodriguez]

What if I have a text file with multiple "trailing new line characters". I just want to append it to the end of another file. This could be a simple copy/paste outside of matlab, but I want to include it in my script.

The file is on the order of 100 lines long, so it would take a lot of "fprintf" with specific formatting for each line.

thanks!

[Stephen23]

"The file is on the order of 100 lines long, so it would take a lot of "fprintf" with specific formatting for each line."

I don't see why: FILEREAD includes all newline characters in its output, so you can simply use one FPRINTF call to print file content together with all of its newline characters. Even if that were not the case (e.g. you imported each line separately into a cell array, sans newline characters) it would still be trivial using just one FPRINTF call (and including the newline in the format string).

So far nothing you have explained requires more than one FPRINTF call.