cat files

[stefanwagner]

I have to append some files together.
The easy description looks like that:

On linux I may say:

cat f.1 f.2 > f.3

On dos i may say

copy -b f.1 + f.2 f.3

Is there an easy way to do something like that in java?

The real description is, that I have to put a String between,
so in pseudocode it is:
file.c = file.a + " some text " + file.b

Of course I can write 'some text' to file.d and use method one if there is one.
And of course I could read file.a, write it to file.c, append text 'some text', read file.b and append it to file.c.

This looks a little bit ugly to me and might be inefficient.
I looked at File, FileChannel, FileWriter and FileOutputStream, but there seems to be nothing close to my Problem.

I remember that this things where easy with c/ c++, but platformdependend of course.

 

[sedj]

Try this ....

String filesIn = "file1.txt file2.txt";
String fileOut ="file3.txt";

BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(new File(fileOut)));

StringTokenizer files = new StringTokenizer(filesIn, " ");
while (files.hasMoreTokens()) {
	File fileIn = new File(files.nextToken());
	BufferedInputStream bis = new BufferedInputStream(new FileInputStream(fileIn));
	byte[] buffer = new byte[(int)fileIn.length()];
	bis.read(buffer, 0, buffer.length);
	bos.write(buffer, 0, buffer.length);
	bos.write("\n".getBytes());
	bos.write("this is some text I put in the middle of a file".getBytes());
	bos.write("\n".getBytes());
	bis.close();
}

bos.flush();
bos.close();

 

[stefanwagner]

I'm afraid, that I did lead you in the wrong direction with my Pseudocode.

I know how to write into a Stream/ File.
I meant to write the context of 'file.a' to 'file.c', append some text, and then append 'file.b'.

I know how to do this by reading file.a and file.b in and writing them bytewise, or Line-by-Line, or bufferwise.

I'm looking for something like (again pseudocode, but more javalike
File file_a, file_c, file_b;
file_a = new File ("f.1"
// ...
file_a.copy_to (file_c);
file_c.append ("some text"
file_c.append (file.b);

 

[sedj]

>>>> file_a.copy_to (file_c);
Read file_a in (using code as above or whatever) and write out the data to file_c.

>>>>> file_c.append ("some text"
Well - the example above does this ... but you can also do it by calling the constructor of FileOutputStream

FileOutputStream(File file, boolean append)

>>> file_c.append (file.b);
The example above does this.

I think the example does do all of the things you require - you just need to modify it a bit - have you tried running it ? file3.txt has the contents of file1.txt, with some appened text in the middle, and then the contents of file2.txt.

Is this not what you wish ?!!

 

[stefanwagner]

No, sorry - it's not.

I have been on the search for a more elegant solution than mine (I already have a working solution).

I thought there might be an solution in the libs somewhere, which I didn't find.

In my first posting I wrote:
'And of course I could read file.a, write it to file.c, append text 'some text', read file.b and append it to file.c.'
And your answer is an Implementation of that.

I hope it was just cut'n paste.