How to compare strings using QString and Qt::MatchFlags for Qt5 and up

The Qt QString class is missing a really great opportunity to use the same Qt::MatchFlags that are used elsewhere in Qt. In the interest of making it super easy to add this functionality to my existing code and yours, just copy the following code into one of your commonly used header files. Make sure to actually include the required headers as shown in the comments. Then you can match your strings using Qt::MatchFlags.


/** determine if the pattern matches the string using Qt::MatchFlags
    \param str the string
    \param pattern the pattern to find
    \param flags any combination of the follow Qt flags
                - Qt::MatchFixedString
                - Qt::MatchContains
                - Qt::MatchStartsWith
                - Qt::MatchEndsWith
                - Qt::MatchRegExp (overrides all flags above)
                - Qt::MatchCaseSensitive
    \returns true if the pattern is found in the string

    requires:
    #include <QString>
    #include <QRegularExpression>
    #include <QRegularExpressionMatch>

    Thank you for visiting sirspot.com
    This code is not guaranteed to work.
    Use at your own risk.
*/
static bool QString_Matches(
    const QString& str,
    const QString& pattern,
    const Qt::MatchFlags& flags = (Qt::MatchCaseSensitive | Qt::MatchFixedString))
{
    if(flags.testFlag(Qt::MatchRegExp) == true)
    {
        QRegularExpression::PatternOptions options = QRegularExpression::NoPatternOption;
        if(flags.testFlag(Qt::MatchCaseSensitive) == false)
        {
            options = QRegularExpression::CaseInsensitiveOption;
        }
        QRegularExpression regex(pattern, options);
        return regex.match(str).hasMatch();
    }
    else
    {
        Qt::CaseSensitivity cs = Qt::CaseSensitive;
        if(flags.testFlag(Qt::MatchCaseSensitive) == false)
        {
            cs = Qt::CaseInsensitive;
        }
        if(flags.testFlag(Qt::MatchContains) == true)
        {
            return str.contains(pattern, cs);
        }
        else
        {
            if(flags.testFlag(Qt::MatchStartsWith) == true)
            {
                if(str.startsWith(pattern, cs) == true)
                {
                    return true;
                }
            }
            if(flags.testFlag(Qt::MatchEndsWith) == true)
            {
                if(str.endsWith(pattern, cs) == true)
                {
                    return true;
                }
            }
            if(flags.testFlag(Qt::MatchFixedString) == true)
            {
                return (str.compare(pattern, cs) == 0);
            }
        }
    }
    return false;
};

Happy String Matching!

VLC Media Player with Telnet (TCP) Control

This post is going to take some time to develop properly.  Here is what to do for those who understand how:

  1. open a command prompt with administrative privileges
  2. change directory to where your VLC exe is found
  3. execute the following command
    vlc -I ntservice --ntservice-install --ntservice-extraintf=telnet --telnet-host=131.185.1.1:4212 --telnet-password=12345
  4. Note: set the ip address to your IP or try 0.0.0.0 if you want to work with all interfaces.  Also, the password is required to make the telnet server work so either keep it as 12345 or select your own.
  5. open a telnet client and connect to TCP port 4212

What is missing?  You may need to enter some firewall rules.  You may need to set some additional configuration options such as which IP to bind to, the port to use, etc.  I’ll try to provide more detailed configuration steps sometime in the future.

Good luck!

 

Is Climate Change and Global Warming Fake News?

It’s really not fake news. The global average temperature is definitely on the rise. What could be considered fake news is how much humans have contributed to the rise in temperature. This is difficult, but not impossible to determine. I think the correlation of the data charted on these two sites is very telling.

https://climate.nasa.gov/climate_resources/24/

https://climate.nasa.gov/vital-signs/global-temperature/

So Yes, global warming is real and humans are responsible.  The next question is, “will it stop or can it be stopped?”  That’s a much harder question to answer!

How to fix Git for Windows login error via HTTPS

There are a lot of ways to login to a Git server, which means there are a lot of ways to also fail. I have a suggestion for you if, after trying everything else, you are still getting this error:

remote: invalid username or password. if you log in via a third party service you must ensure you have an account password set in your account profile.

Open a command prompt as administrator and enter the following commands:

git config –global –unset credential.helper

git config –system –unset credential.helper

Make sure you do both.

Now attempt to pull from the server again. This time you should be asked for your user name and password. Make sure you use the username that is in the URL of your request. For example, in this URL: https://gituser@sirspot.com the user name is gituser.

I hope this helped!

 

Hour of Code

Last year I went to 3 schools for Hour of Code.  This year I have already been to 3 schools and am schedule to visit 2 more schools before the end of the week.  The students range in age from 6 years old to 13 years old.  I tailor my presentation to each class based on how responsive the students are.  It is a lot of fun!  If you don’t know what Hour of Code is, you can visit the official site here: https://code.org/learn but basically it is just a week out of the year when we try to get students interested in computer programming.  Have a great week and give the Hour of Code a try!

Qt 5.7 Designer Hangs and Causes VS2013 to Hang

Apparently designer.exe hangs if the new webengine dlls are present.  The dlls can be removed, but then, what if you need them?  The easiest way around this problem for me was to use the mingw Qt 5.7 binaries for designer.exe (without including webengine) and leave the vs2013 binaries alone.  I’m sure Qt will be fixed soon, but this will get you rolling in the mean time.  Happy Coding!

Possibly the best Linux find command examples

If you have been looking for a file on Mac OS X or Linux or Unix, you want to use the “find” command. The problem with the find command is that the usage information at the command line is just terrible. The solution is to bookmark this awesome website:
http://www.thegeekstuff.com/2009/03/15-practical-linux-find-command-examples/

Here are some of my favorites:

Find a file by name in any directory starting with the root path

find / -name passwd

Find a file by name (case-insensitive) starting at the current directory and then run the command md5sum on each file that matches.

find -iname "MyCProgram.c" -exec md5sum {} \;

Find files starting in your home directory that are larger than 100 megatbytes.

find ~ -size +100M

And last, but not least, create an alias for a find command that will remove all files named “a.out” starting from the current directory

alias rmao="find . -iname a.out -exec rm {} \;"
rmao

Happy Hunting!

How to make Mac OS X and MySQL happy with Qt

Using shared libraries on Mac OS X is one of the things that is actually a lot harder than on Windows.  For example, you cannot just put the shared library for MySQL into your path or into the working directory. You have to change the plugin file itself to make it look in the correct location. You find the current value using the command “otool” and change the value using the command “install_name_tool”. Here is an example:

cd Qt/5.4/clang_64/plugins/sqldrivers/

otool -L libqsqlmysql.dylib 

libqsqlmysql.dylib:
libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
/opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib (compatibility version 18.0.0, current version 18.0.0)
...

install_name_tool -change /opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.20.dylib ./libqsqlmysql.dylib 

otool -L libqsqlmysql.dylib 

libqsqlmysql.dylib:
libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
/usr/local/mysql/lib/libmysqlclient.20.dylib (compatibility version 18.0.0, current version 18.0.0)
...