Questions[diff](ubuntu)

I am looking for an application that can compare two C++ sources and find the code-meaningful differences (to compare versions which may have been reformatted differently). At the very minimum, something which has the capability for ignoring changes in white spaces, tab spaces and newlines which do not affect the functionality of the source (note that whether a newline is considered whitespace is language-dependent, and C and C++ do so). And, ideally, something that can identify exactly all code-meaningful differences. I am under Ubuntu.

As per diff --help | grep ignore, I expected diff -bBwZ to do reasonably the job (I expected to get some false negatives, to be dealt with later). Nevertheless, it doesn't.

if I have the following files with snippets

test_diff1.txt

    else if (prop == "P1") { return 0; }

and test_diff2.txt

    else if (prop == "P1") {
        return 0;
    }

then

$ diff -bBwZ test_diff1.txt test_diff2.txt
1c1,3
<     else if (prop == "P1") { return 0; }
---
>     else if (prop == "P1") {
>         return 0;
>     }

instead of empty results.

Using a code formatter as a "filter" on both inputs may filter out these differences, but then the resulting output would have to be tied back to the original inputs for the final reporting of differences to keep actual text and line numbers. So the objective is attainable without a need for a compiler properly... I do not know if something is available, though.

Can the objective be attained with diff? Otherwise, is there an alternative (preferably, for command line)?

I am using meld to visualise a diff between two files. meld shows the diff output in... something like Japanese or Chinese?

Any idea what could happen? A locale issue? What is strange is that when using diff or colordiff in terminal, they work perfectly!

Thanks!

I have installed Meld and found out it's a great comparing tool. Unfortunately there is no integration with Nautilus 3.2. This means, I can't right click on files and select an option to open them in Meld for comparison.

I have seen in the tools comment that the tool need the diff-ext package to be installed. This package has been removed from Ubuntu universe, I am guessing because gtk 3.0. Even if I manually downloaded from source forge the diff-ext package, when I try to configure it the check fails with the message:

checking for DIFF_EXT... configure: error: Package requirements (libnautilus-extension >= 2.14.0 gconf-2.0 >= 2.14.0 gnome-vfs-module-2.0 >= 2.14) were not met:

No package 'libnautilus-extension' found
No package 'gconf-2.0' found
No package 'gnome-vfs-module-2.0' found

Ok, so from this output I gather that indeed gtk 2 is being required to install the diff extension to nautilus.

Now, my question is: Is there a possibility to integrate Meld into Nautilus? Or, are there any other diff based tool which integrate with current Nautilus? So gtk3 based.

I am using Ubuntu 11.10 if there was any doubt so far.

I am trying to find diffs between all files of same names across two copies of a directory (say a working and a backup). For example, I can diff two files of same name in both:

> diff d1/f.cpp d2/f.cpp

or I can find differences across the directories:

> diff d1 d2

but how can I find differences between the *.cpp files only?

> diff d1/*.cpp d2/*.cpp

does not seem to work (for obvious reasons).

[It is probably easy to solve with loops, but I am trying to find a more elegant way]

I'm looking for something that will compare directories and files like Beyond Compare does for windows.

Its mainly for use of source control, but I need to use it for deployment as well.