How to insert new empty lines in middle of an exisiting text file

Hello,

i have the following problem: I have a txt.file into which i want to add a couple of new empty lines at a certain position (row number).

Old Text File: Line1 Line2 Line3 Line4

New Txt File: Line1 Line2 New Empty Line New Empty Line Line3 Line4

Thanks for your help

[Adam]

Read in all the data after the point you want to insert the empty line, then write it back out (making sure you append to the existing file, not overwrite it) with the empty lines added in front.

[Omar Shehata]

@Adam

Im sorry, im new to Matlab. Can you write like a small code or pseudocode regarding this.

[Kevin Xia]

How are you representing the new empty lines? With whitespace?

[Omar Shehata]

with sprintf('\n');

Answer 1

[Kevin Xia]

Try using the functions importdata and strjoin with '\n' as the delimiter. importdata will give output a cell array that you can insert an extra row in. Something like:

rowNum=3;
textlines=[textlines(1:rowNum);sprintf('\n');textlines(rowNum+1:end)]

will insert a newline into the cell array at the desired row number. Strjoin can join the cell array together into a character array, which can be printed to a file using fopen and fprintf. Please see the documentation for these functions for more details.

Answer 2

[Guillaume]

One of the many possible ways to do this:

filepath = 'c:\somewhere\somefile.txt;
contents = fileread(filepath);
lines = strsplit(contents, '\n', 'CollapseDelimiters', false);  
newlines = [lines(1:2), {'', ''}, lines(3:end)];  %to insert two blank lines at line 3
newcontents = strjoin(newlines, '\n');
fid = fopen(filepath, 'w');
fwrite(fid, newcontents);
fclose(fid);