CODEWITHSUNDEEP
matlabfile-io
Molitoris
Molitoris

Reputation: 1035

Append content of one file to another file without loosing formatting

I have several files in .txt format. My goal is to unify the content of all these files into a source file (also .txt format) without changing the formatting. To start, I just want to copy the content from one file to another.

The following code snip allows to copy the content. However, I lose the formatting.

%   load destination file in append mode
destFileId = fopen(destFile, "a");
%   load source file in read mode
sourceFileId = fopen(sourceFile, "r");

%   Extract content from source file
content = textscan(sourceFileId, '%c');

%   Append content into destination file
fprintf(destFileId, content{:});

%   Close both files
fclose(destFileId);
fclose(sourceFileId);

Upvotes: 0

Views: 304

Answers (2)

jodag
jodag

Reputation: 22304

The problem with using fprintf to concatenate files is that if the file contains special characters (like \ or %) then fprintf will likely fail. A very similar approach would be to use fread and fwrite to directly concatenate the file contents without interpreting them in any way.

function catfiles(dest, sources)
    fdest = fopen(dest, 'wb');

    for source = 1:numel(sources)
        fsource = fopen(source,'rb');
        source_data = fread(fsource);
        fwrite(fdest, source_data);
        fclose(fsource);
    end

    fclose(fdest);

Usage

>> catfiles('dest.txt', {'source1.txt', 'source2.txt'});

I didn't include all the checks that @CitizenInsane's answer does but they are a good idea.

Upvotes: 1

CitizenInsane
CitizenInsane

Reputation: 4875

I think using fileread instead of textscan will help in preserving formattiing as you wish to (fileread reads whole file content as a simple matlab string, preserving both for whitespaces and newlines)

Here is some pseudo code (not tested):

 function [] = Dummy(desFile, sourcesFiles)
 %[
    % Open destination file for writing (discarding previous content)
    [destFileId, msg] = fopen(destFile, 'w');
    if (desFileId < 0), error(msg); end

    % Make sure to close file on any error, ctrl+c (and normal termination of course)
    cuo = onCleanup(@()fclose(destFileId));

    % Copy file contents to destination
    count = length(sourcesFiles);
    for fi = 1:count,

        text = fileread(sourcesFiles{fi});
        fprintf(destFileId, '%s', text);

    end
 %]

Upvotes: 4

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