c++: auto_ptr::release()

auto_ptr::release()

The release() function removes ownership of the stored object from the
invoking auto_ptr and returns a pointer to the object. After a call to release(),
the pointed-to object is not automatically destroyed when the auto_ptr object
goes out of scope.

 -- Herb Schildt's C++ Programming Cookbook, Chapter 7, page 489

c++: deleting elements from a map

Q: Does std::map.erase() properly delete pointers, or does it create memory leaks?

A: It properly does not delete pointers, because it can't assume that nothing else points at the same thing. std::map cleans up the memory *it* explicitly allocated. *You* clean up the memory *you* explicitly allocated.


Here's how to safely delete all elements in a map, that will work for any container:

std::map<int, char*> Mappy;

int main()
{
    for(int Index = 0; Index < 10; ++Index)
    Mappy.insert(std::make_pair(Index, new char[10]));

    for(std::map<int, char*>::iterator MapItor = Mappy.begin(); MapItor != Mappy.end(); ++MapItor)
    {
        char* Value = (*MapItor).second;
        delete Value;
    }

    system("pause");
    return 0;
}

visual studio: how to show the full file path in the title bar

http://www.helixoft.com/blog/archives/32

batch file to fix WMI errors

There's a lot to learn about batch file scripting from this example!
source

net stop winmgmt

pause

c:

cd c:\windows\system32\wbem

rd /S /Q repository

regsvr32 /s %systemroot%\system32\scecli.dll

regsvr32 /s %systemroot%\system32\userenv.dll

mofcomp cimwin32.mof

mofcomp cimwin32.mfl

mofcomp rsop.mof

mofcomp rsop.mfl

for /f %%s in ('dir /b /s *.dll') do regsvr32 /s %%s

for /f %%s in ('dir /b *.mof') do mofcomp %%s

for /f %%s in ('dir /b *.mfl') do mofcomp %%s

mofcomp exwmi.mof

mofcomp -n:root\cimv2\applications\exchange wbemcons.mof

mofcomp -n:root\cimv2\applications\exchange smtpcons.mof

mofcomp exmgmt.mof

linux: adding swap space on-the-fly to your system

You might find that the swap partition you specified at install-time just isn't enough anymore. Maybe you've added more RAM to your machine and need to increase the swap partition accordingly. Or maybe you're upgrading your system to a version that uses more swap in relation to physical RAM. Perhaps you're running Oracle. In case your machine is swapping like mad and you just can't take it down right now to add more RAM, you can add more swap space on the fly using the following procedure. As an example, to keep the machine from running out of memory entirely and freezing up, we'll add 128 MB more swap space by creating a swap file. First we check out the memory usage:

[root@domain /root]# free -m
total       used       free     shared    buffers     cached
Mem:           251        242          8         22         11         32
-/+ buffers/cache:        198         52
Swap:          133        133          0

Make sure we have 128 MB laying around somewhere:

[root@domain /root]# df
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hda9               132207     33429     91952  27% /
/dev/hda1                15522      2537     12184  17% /boot
/dev/hda6              6143236    739000   5092176  13% /opt
/dev/hda7              1035660    836204    146848  85% /usr
/dev/hda5              2071384    344048   1622112  17% /usr/local
/dev/hda8               303344     14439    273244   5% /var

OK, we're going to make a swap file in /opt by using dd to create a file 128 MB in size.

[root@domain /opt]# dd if=/dev/zero of=swapfile bs=1024 count=132207
132207+0 records in
132207+0 records out
[root@domain /opt]# ls -l
total 132364
drwxr-xr-x   20 usr-3 users        4096 May 22 10:46 usr-3
drwxr-xr-x    2 root     root        16384 Feb 21 07:04 lost+found
-rw-r--r--    1 root     root     135379968 May 29 11:52 swapfile

Let's not make it world-readable...

[root@domain /opt]# chmod 600 swapfile
[root@domain /opt]# ls -l
total 132364
drwxr-xr-x   20 usr-3 users        4096 May 22 10:46 usr-3
drwxr-xr-x    2 root     root        16384 Feb 21 07:04 lost+found
-rw-------    1 root     root     135379968 May 29 11:52 swapfile

Now we set up the swap area and enable it.

[root@domain /opt]# mkswap swapfile
Setting up swapspace version 1, size = 135372800 bytes
[root@domain /opt]# swapon swapfile

And voila! Twice as much swap as before.

[root@domain /opt]# free
total       used       free     shared    buffers     cached
Mem:        257632     254632       3000       2512      36172      15096
-/+ buffers/cache:     203364      54268
Swap:       268708     136512     132196

You can append a line like this to /etc/fstab to enable your swap file automatically at boot time:

/opt/swapfile           swap                    swap    defaults        0 0

source

python: writing your own urllib2 redirect_handler

class SmartRedirectHandler(urllib2.HTTPRedirectHandler):

    def redirect_request(self, req, fp, code, msg, headers, newurl=''):
        global intermediateURL
        intermediateURL = newurl

        if code in (301, 302, 303, "refresh") or (code == 307 and not req.has_data()):
            newRequest = urllib2.Request(   
                                            newurl,
                                            headers=req.headers,
                                            origin_req_host=req.get_origin_req_host(),
                                            unverifiable=True
                                        )
            newRequest._origin_req = getattr(req, "_origin_req", req)
            
        return newRequest
        
        else:
            raise HTTPError(req.get_full_url(), code, msg, headers, fp)

source

how to enable tap zones on dell mouse drivers

To unlock the native touchpad features which are masked by Dell's touchpad software:

1. Go to control panel and select MOUSE to see what options are available (very few) and close that all up.

2. Next click on the Windows Start icon and type regedit in the search box.
Windows Registry will open.

Navigate to HKEY_LOCALMACHINE\SOFTWARE\Alps\Apoint and look for the key UseCustomGUI (it's the 2nd to last entry on the list)

Change the value from 1 to 0 and click on OK

3. Next minimize the registry (don't close it yet).
Goto Control Panel and select MOUSE.
Now all the ALPs settings are unlocked and appear here.

For example the GESTURES feature is now showing.
Select GESTURES tab and check ON the box for
Use Back/Forward Buttons.
Then click APPLY and OK.
Close the Mouse settings and close the Control panel.

4. Now go back to your registry setting and change
UseCustomGUI back to it's original value of 1 and close it and the reg editor.

Everything is back exactly as it was but the feature remains enabled.

All done....now when your surfing just swipe your finger along the top edge of the touch pad to go back and forward.


source