Where have my Konqueror favicons gone?

I upgraded to KDE 4.13.0 recently only to find that Konqueror no longer displayed some of the favicons, neither in the Bookmarks menu nor in the URL address bar. It seems this is a known KDE bug first reported in 2007 (Bug 153049 – Konqueror from KDE4 doesn’t load some favicons) although apparently it does not affect many users, which is why it still has not been fixed, I suppose.

In 2010 a KDE user reported in the KDE Community Forums thread Konqueror favicons again the steps he used to fix the problem in his installation, but he did not give the precise file names and paths of the files he deleted. In any case, I did not fancy deleting any sockets.

I tried various things, such as exporting and reimporting bookmarks in Konqueror, but was unable to get the missing favicons to display again. In the end I accepted I would have to lose all my bookmarks and decided to reinstall Konqueror. However, not all files are removed when a package is uninstalled, so I made sure everything was gone as follows:

1. Uninstall Konqueror

# emerge -C konqueror

2. Delete left-over directories and files relating to Konqueror

# rm -rf /home/fitzcarraldo/.kde4/share/apps/konqueror/
# rm /home/fitzcarraldo/.kde4/share/config/konq*

3. Log out of KDE and switch to a VT (virtual terminal, a.k.a. console)

# rm /var/tmp/kdecache-fitzcarraldo/favicons/*
# rm /var/tmp/kdecache-fitzcarraldo/icon-cache.kcache

4. Log in to KDE again and re-install Konqueror

# emerge -1v konqueror

5. Launch Konqueror and bookmark all your favourite Web sites.

That will get favicons working again in Konqueror, but what a hassle. KDE developers, please fix this old bug (no. 153049)!

Using KWrite to find and replace a character with a CRLF (Carriage Return/Line Feed)

Occasionally I need to edit a long string and replace the space character with a CRLF and some text. Even though I was sure the KDE editor KWrite could do that, I had never bothered to find out how. Today I finally bit the bullet. It’s not difficult, of course. To show you how it is done, I’ll give an actual example…

I wanted to edit in KWrite the single line of text shown below. (Not that it’s relevant to the subject of this post, but the line was a command to the Gentoo package manager to install a long list of packages, and I wanted to split it into separate commands in order to install each package individually.)

emerge -vD1 --backtrack=30 media-video/dvdrip:0 dev-vcs/git:0 dev-vcs/subversion:0 net-print/foomatic-db-engine:0 app-antivirus/clamtk:0 dev-perl/XML-SAX:0 dev-perl/X11-Protocol:0 dev-perl/Goo-Canvas:0 dev-perl/Readonly:0 dev-perl/File-Find-Rule:0 dev-perl/Net-SSLeay:0 dev-perl/XML-LibXML:0 dev-perl/HTTP-Message:0 dev-perl/Digest-SHA1:0 dev-perl/XML-XPath:0 dev-perl/File-Which:0 dev-perl/Authen-SASL:0 dev-perl/glib-perl:0 dev-perl/prefork:0 dev-perl/IO-Socket-SSL:0 dev-perl/Exception-Class:0 dev-perl/Proc-Simple:0 dev-perl/WWW-Mechanize:0 dev-perl/gnome2-canvas:0 dev-perl/gnome2-vfs-perl:0 dev-perl/IO-String:0 dev-perl/HTML-Tagset:0 dev-perl/Carp-Clan:0 dev-perl/Pod-Spell:0 dev-perl/Sane:0 dev-perl/TermReadKey:0 dev-perl/HTTP-Date:0 dev-perl/Encode-Locale:0 dev-perl/Event-RPC:0 dev-perl/File-HomeDir:0 dev-perl/Bit-Vector:0 dev-perl/gnome2-wnck:0 dev-perl/File-Copy-Recursive:0 dev-perl/Text-Unidecode:0 dev-perl/Unicode-EastAsianWidth:0 dev-perl/extutils-pkgconfig:0 dev-perl/Clone:0 dev-perl/Event-ExecFlow:0 dev-perl/B-Keywords:0 dev-perl/PDF-API2:0 dev-perl/HTTP-Negotiate:0 dev-perl/HTML-Form:0 dev-perl/extutils-depends:0 dev-perl/PlRPC:0 dev-perl/libwww-perl:0 dev-perl/gtk2-perl:0 dev-perl/File-MimeInfo:0 dev-perl/Font-TTF:0 dev-perl/libintl-perl:0 dev-perl/List-MoreUtils:0 dev-perl/Log-Log4perl:0 dev-perl/XML-DOM:0 dev-perl/HTML-Parser:0 dev-perl/Try-Tiny:0 dev-perl/XML-Twig:0 dev-perl/Gtk2-Ex-Simple-List:0 dev-perl/LWP-MediaTypes:0 dev-perl/LWP-Protocol-https:0 dev-perl/XML-Simple:0 dev-perl/Pango:0 dev-perl/set-scalar:0 dev-perl/Gtk2-Unique:0 dev-perl/Params-Util:0 dev-perl/Net-Daemon:0 dev-perl/GSSAPI:0 dev-perl/XML-NamespaceSupport:0 dev-perl/PPI:0 dev-perl/Proc-ProcessTable:0 dev-perl/String-Format:0 dev-perl/Date-Calc:0 dev-perl/XML-Parser:0 dev-perl/Email-Address:0 dev-perl/Class-Data-Inheritable:0 dev-perl/Email-Simple:0 dev-perl/JSON:0 dev-perl/gnome2-perl:0 dev-perl/XML-SAX-Base:0 dev-perl/Net-SMTP-SSL:0 dev-perl/Gtk2-ImageView:0 dev-perl/IO-HTML:0 dev-perl/WWW-RobotRules:0 dev-perl/Digest-HMAC:0 dev-perl/HTTP-Cookies:0 dev-perl/DBI:0 dev-perl/URI:0 dev-perl/Text-Iconv:0 dev-perl/gtk2-ex-formfactory:0 dev-perl/Email-Date-Format:0 dev-perl/libxml-perl:0 dev-perl/XML-SAX-Writer:0 dev-perl/XML-Filter-BufferText:0 dev-perl/Number-Compare:0 dev-perl/XML-RegExp:0 dev-perl/Email-LocalDelivery:0 dev-perl/config-general:0 dev-perl/HTTP-Daemon:0 dev-perl/File-Listing:0 dev-perl/Devel-StackTrace:0 dev-perl/Set-IntSpan:0 dev-perl/Cairo:0 dev-perl/Email-FolderType:0 dev-perl/XML-Handler-YAWriter:0 dev-perl/Archive-Zip:0 dev-perl/Net-DBus:0 dev-perl/DBD-mysql:0 dev-perl/AnyEvent:0 dev-perl/perltidy:0 dev-perl/Locale-gettext:0 dev-perl/Sort-Naturally:0 dev-perl/Net-HTTP:0 dev-perl/Perl-Critic:0 media-gfx/gscan2pdf:0 media-libs/exiftool:0 perl-core/CPAN-Meta-Requirements:0 virtual/perl-CPAN-Meta-Requirements:0 perl-core/IPC-Cmd:0 virtual/perl-IPC-Cmd:0 perl-core/Storable:0 virtual/perl-Storable:0 perl-core/File-Spec:0 virtual/perl-File-Spec:0 perl-core/CPAN-Meta:0 virtual/perl-CPAN-Meta:0 perl-core/Getopt-Long:0 virtual/perl-Getopt-Long:0 perl-core/Locale-Maketext-Simple:0 virtual/perl-Locale-Maketext-Simple:0 perl-core/ExtUtils-Manifest:0 virtual/perl-ExtUtils-Manifest:0 perl-core/Pod-Simple:0 virtual/perl-Pod-Simple:0 perl-core/CPAN-Meta-YAML:0 virtual/perl-CPAN-Meta-YAML:0 perl-core/Encode:0 virtual/perl-Encode:0 perl-core/Compress-Raw-Bzip2:0 virtual/perl-Compress-Raw-Bzip2:0 perl-core/Module-Load:0 virtual/perl-Module-Load:0 perl-core/Archive-Tar:0 virtual/perl-Archive-Tar:0 perl-core/Scalar-List-Utils:0 virtual/perl-Scalar-List-Utils:0 perl-core/ExtUtils-CBuilder:0 virtual/perl-ExtUtils-CBuilder:0 perl-core/Parse-CPAN-Meta:0 virtual/perl-Parse-CPAN-Meta:0 perl-core/version:0 virtual/perl-version:0 perl-core/Digest-SHA:0 virtual/perl-Digest-SHA:0 perl-core/Module-Load-Conditional:0 virtual/perl-Module-Load-Conditional:0 perl-core/Compress-Raw-Zlib:0 virtual/perl-Compress-Raw-Zlib:0 perl-core/ExtUtils-Install:0 virtual/perl-ExtUtils-Install:0 perl-core/IO:0 virtual/perl-IO:0 perl-core/Time-Local:0 virtual/perl-Time-Local:0 perl-core/Module-CoreList:0 virtual/perl-Module-CoreList:0 perl-core/Digest-MD5:0 virtual/perl-Digest-MD5:0 perl-core/JSON-PP:0 virtual/perl-JSON-PP:0 perl-core/ExtUtils-ParseXS:0 virtual/perl-ExtUtils-ParseXS:0 perl-core/File-Temp:0 virtual/perl-File-Temp:0 perl-core/Params-Check:0 virtual/perl-Params-Check:0 perl-core/Module-Metadata:0 virtual/perl-Module-Metadata:0 perl-core/Sys-Syslog:0 virtual/perl-Sys-Syslog:0 perl-core/IO-Compress:0 virtual/perl-IO-Compress:0 perl-core/Test-Harness:0 virtual/perl-Test-Harness:0

With the above line of text in a KWrite window, I did the following:

1. I selected Edit > Replace… from the KWrite menu.

2. At the bottom of the KWrite window, I changed the Mode from ‘Plain text’ to ‘Regular expression’.

3. I clicked in the ‘Find’ box and pressed the Space bar to enter a space character.

4. I clicked in the ‘Replace’ box and entered the following text (note that there is ‘\n’ at the beginning and a space at the end):

\nemerge -vD1 --backtrack=30 

The ‘\n‘ represents a CRLF (Carriage Return plus Line Feed).

5. I ticked ‘Selection only’.

6. With the mouse I selected the text in which I wanted to make the replacement, i.e. I selected from (and including) the space following the first package (media-video/dvdrip:0) all the way to the end of the line.

7. I clicked on ‘Replace All’.

The result looked like this:

emerge -vD1 --backtrack=30 media-video/dvdrip:0
emerge -vD1 --backtrack=30 dev-vcs/git:0
emerge -vD1 --backtrack=30 dev-vcs/subversion:0
emerge -vD1 --backtrack=30 net-print/foomatic-db-engine:0
emerge -vD1 --backtrack=30 app-antivirus/clamtk:0
emerge -vD1 --backtrack=30 dev-perl/XML-SAX:0
emerge -vD1 --backtrack=30 dev-perl/X11-Protocol:0
emerge -vD1 --backtrack=30 dev-perl/Goo-Canvas:0
emerge -vD1 --backtrack=30 dev-perl/Readonly:0
emerge -vD1 --backtrack=30 dev-perl/File-Find-Rule:0
emerge -vD1 --backtrack=30 dev-perl/Net-SSLeay:0
emerge -vD1 --backtrack=30 dev-perl/XML-LibXML:0
emerge -vD1 --backtrack=30 dev-perl/HTTP-Message:0
emerge -vD1 --backtrack=30 dev-perl/Digest-SHA1:0
emerge -vD1 --backtrack=30 dev-perl/XML-XPath:0
emerge -vD1 --backtrack=30 dev-perl/File-Which:0
emerge -vD1 --backtrack=30 dev-perl/Authen-SASL:0
emerge -vD1 --backtrack=30 dev-perl/glib-perl:0
emerge -vD1 --backtrack=30 dev-perl/prefork:0
emerge -vD1 --backtrack=30 dev-perl/IO-Socket-SSL:0
emerge -vD1 --backtrack=30 dev-perl/Exception-Class:0
emerge -vD1 --backtrack=30 dev-perl/Proc-Simple:0
emerge -vD1 --backtrack=30 dev-perl/WWW-Mechanize:0
emerge -vD1 --backtrack=30 dev-perl/gnome2-canvas:0
emerge -vD1 --backtrack=30 dev-perl/gnome2-vfs-perl:0
emerge -vD1 --backtrack=30 dev-perl/IO-String:0
emerge -vD1 --backtrack=30 dev-perl/HTML-Tagset:0
emerge -vD1 --backtrack=30 dev-perl/Carp-Clan:0
emerge -vD1 --backtrack=30 dev-perl/Pod-Spell:0
emerge -vD1 --backtrack=30 dev-perl/Sane:0
emerge -vD1 --backtrack=30 dev-perl/TermReadKey:0
emerge -vD1 --backtrack=30 dev-perl/HTTP-Date:0
emerge -vD1 --backtrack=30 dev-perl/Encode-Locale:0
emerge -vD1 --backtrack=30 dev-perl/Event-RPC:0
emerge -vD1 --backtrack=30 dev-perl/File-HomeDir:0
emerge -vD1 --backtrack=30 dev-perl/Bit-Vector:0
emerge -vD1 --backtrack=30 dev-perl/gnome2-wnck:0
emerge -vD1 --backtrack=30 dev-perl/File-Copy-Recursive:0
emerge -vD1 --backtrack=30 dev-perl/Text-Unidecode:0
emerge -vD1 --backtrack=30 dev-perl/Unicode-EastAsianWidth:0
emerge -vD1 --backtrack=30 dev-perl/extutils-pkgconfig:0
emerge -vD1 --backtrack=30 dev-perl/Clone:0
emerge -vD1 --backtrack=30 dev-perl/Event-ExecFlow:0
emerge -vD1 --backtrack=30 dev-perl/B-Keywords:0
emerge -vD1 --backtrack=30 dev-perl/PDF-API2:0
emerge -vD1 --backtrack=30 dev-perl/HTTP-Negotiate:0
emerge -vD1 --backtrack=30 dev-perl/HTML-Form:0
emerge -vD1 --backtrack=30 dev-perl/extutils-depends:0
emerge -vD1 --backtrack=30 dev-perl/PlRPC:0
emerge -vD1 --backtrack=30 dev-perl/libwww-perl:0
emerge -vD1 --backtrack=30 dev-perl/gtk2-perl:0
emerge -vD1 --backtrack=30 dev-perl/File-MimeInfo:0
emerge -vD1 --backtrack=30 dev-perl/Font-TTF:0
emerge -vD1 --backtrack=30 dev-perl/libintl-perl:0
emerge -vD1 --backtrack=30 dev-perl/List-MoreUtils:0
emerge -vD1 --backtrack=30 dev-perl/Log-Log4perl:0
emerge -vD1 --backtrack=30 dev-perl/XML-DOM:0
emerge -vD1 --backtrack=30 dev-perl/HTML-Parser:0
emerge -vD1 --backtrack=30 dev-perl/Try-Tiny:0
emerge -vD1 --backtrack=30 dev-perl/XML-Twig:0
emerge -vD1 --backtrack=30 dev-perl/Gtk2-Ex-Simple-List:0
emerge -vD1 --backtrack=30 dev-perl/LWP-MediaTypes:0
emerge -vD1 --backtrack=30 dev-perl/LWP-Protocol-https:0
emerge -vD1 --backtrack=30 dev-perl/XML-Simple:0
emerge -vD1 --backtrack=30 dev-perl/Pango:0
emerge -vD1 --backtrack=30 dev-perl/set-scalar:0
emerge -vD1 --backtrack=30 dev-perl/Gtk2-Unique:0
emerge -vD1 --backtrack=30 dev-perl/Params-Util:0
emerge -vD1 --backtrack=30 dev-perl/Net-Daemon:0
emerge -vD1 --backtrack=30 dev-perl/GSSAPI:0
emerge -vD1 --backtrack=30 dev-perl/XML-NamespaceSupport:0
emerge -vD1 --backtrack=30 dev-perl/PPI:0
emerge -vD1 --backtrack=30 dev-perl/Proc-ProcessTable:0
emerge -vD1 --backtrack=30 dev-perl/String-Format:0
emerge -vD1 --backtrack=30 dev-perl/Date-Calc:0
emerge -vD1 --backtrack=30 dev-perl/XML-Parser:0
emerge -vD1 --backtrack=30 dev-perl/Email-Address:0
emerge -vD1 --backtrack=30 dev-perl/Class-Data-Inheritable:0
emerge -vD1 --backtrack=30 dev-perl/Email-Simple:0
emerge -vD1 --backtrack=30 dev-perl/JSON:0
emerge -vD1 --backtrack=30 dev-perl/gnome2-perl:0
emerge -vD1 --backtrack=30 dev-perl/XML-SAX-Base:0
emerge -vD1 --backtrack=30 dev-perl/Net-SMTP-SSL:0
emerge -vD1 --backtrack=30 dev-perl/Gtk2-ImageView:0
emerge -vD1 --backtrack=30 dev-perl/IO-HTML:0
emerge -vD1 --backtrack=30 dev-perl/WWW-RobotRules:0
emerge -vD1 --backtrack=30 dev-perl/Digest-HMAC:0
emerge -vD1 --backtrack=30 dev-perl/HTTP-Cookies:0
emerge -vD1 --backtrack=30 dev-perl/DBI:0
emerge -vD1 --backtrack=30 dev-perl/URI:0
emerge -vD1 --backtrack=30 dev-perl/Text-Iconv:0
emerge -vD1 --backtrack=30 dev-perl/gtk2-ex-formfactory:0
emerge -vD1 --backtrack=30 dev-perl/Email-Date-Format:0
emerge -vD1 --backtrack=30 dev-perl/libxml-perl:0
emerge -vD1 --backtrack=30 dev-perl/XML-SAX-Writer:0
emerge -vD1 --backtrack=30 dev-perl/XML-Filter-BufferText:0
emerge -vD1 --backtrack=30 dev-perl/Number-Compare:0
emerge -vD1 --backtrack=30 dev-perl/XML-RegExp:0
emerge -vD1 --backtrack=30 dev-perl/Email-LocalDelivery:0
emerge -vD1 --backtrack=30 dev-perl/config-general:0
emerge -vD1 --backtrack=30 dev-perl/HTTP-Daemon:0
emerge -vD1 --backtrack=30 dev-perl/File-Listing:0
emerge -vD1 --backtrack=30 dev-perl/Devel-StackTrace:0
emerge -vD1 --backtrack=30 dev-perl/Set-IntSpan:0
emerge -vD1 --backtrack=30 dev-perl/Cairo:0
emerge -vD1 --backtrack=30 dev-perl/Email-FolderType:0
emerge -vD1 --backtrack=30 dev-perl/XML-Handler-YAWriter:0
emerge -vD1 --backtrack=30 dev-perl/Archive-Zip:0
emerge -vD1 --backtrack=30 dev-perl/Net-DBus:0
emerge -vD1 --backtrack=30 dev-perl/DBD-mysql:0
emerge -vD1 --backtrack=30 dev-perl/AnyEvent:0
emerge -vD1 --backtrack=30 dev-perl/perltidy:0
emerge -vD1 --backtrack=30 dev-perl/Locale-gettext:0
emerge -vD1 --backtrack=30 dev-perl/Sort-Naturally:0
emerge -vD1 --backtrack=30 dev-perl/Net-HTTP:0
emerge -vD1 --backtrack=30 dev-perl/Perl-Critic:0
emerge -vD1 --backtrack=30 media-gfx/gscan2pdf:0
emerge -vD1 --backtrack=30 media-libs/exiftool:0
emerge -vD1 --backtrack=30 perl-core/CPAN-Meta-Requirements:0
emerge -vD1 --backtrack=30 virtual/perl-CPAN-Meta-Requirements:0
emerge -vD1 --backtrack=30 perl-core/IPC-Cmd:0
emerge -vD1 --backtrack=30 virtual/perl-IPC-Cmd:0
emerge -vD1 --backtrack=30 perl-core/Storable:0
emerge -vD1 --backtrack=30 virtual/perl-Storable:0
emerge -vD1 --backtrack=30 perl-core/File-Spec:0
emerge -vD1 --backtrack=30 virtual/perl-File-Spec:0
emerge -vD1 --backtrack=30 perl-core/CPAN-Meta:0
emerge -vD1 --backtrack=30 virtual/perl-CPAN-Meta:0
emerge -vD1 --backtrack=30 perl-core/Getopt-Long:0
emerge -vD1 --backtrack=30 virtual/perl-Getopt-Long:0
emerge -vD1 --backtrack=30 perl-core/Locale-Maketext-Simple:0
emerge -vD1 --backtrack=30 virtual/perl-Locale-Maketext-Simple:0
emerge -vD1 --backtrack=30 perl-core/ExtUtils-Manifest:0
emerge -vD1 --backtrack=30 virtual/perl-ExtUtils-Manifest:0
emerge -vD1 --backtrack=30 perl-core/Pod-Simple:0
emerge -vD1 --backtrack=30 virtual/perl-Pod-Simple:0
emerge -vD1 --backtrack=30 perl-core/CPAN-Meta-YAML:0
emerge -vD1 --backtrack=30 virtual/perl-CPAN-Meta-YAML:0
emerge -vD1 --backtrack=30 perl-core/Encode:0
emerge -vD1 --backtrack=30 virtual/perl-Encode:0
emerge -vD1 --backtrack=30 perl-core/Compress-Raw-Bzip2:0
emerge -vD1 --backtrack=30 virtual/perl-Compress-Raw-Bzip2:0
emerge -vD1 --backtrack=30 perl-core/Module-Load:0
emerge -vD1 --backtrack=30 virtual/perl-Module-Load:0
emerge -vD1 --backtrack=30 perl-core/Archive-Tar:0
emerge -vD1 --backtrack=30 virtual/perl-Archive-Tar:0
emerge -vD1 --backtrack=30 perl-core/Scalar-List-Utils:0
emerge -vD1 --backtrack=30 virtual/perl-Scalar-List-Utils:0
emerge -vD1 --backtrack=30 perl-core/ExtUtils-CBuilder:0
emerge -vD1 --backtrack=30 virtual/perl-ExtUtils-CBuilder:0
emerge -vD1 --backtrack=30 perl-core/Parse-CPAN-Meta:0
emerge -vD1 --backtrack=30 virtual/perl-Parse-CPAN-Meta:0
emerge -vD1 --backtrack=30 perl-core/version:0
emerge -vD1 --backtrack=30 virtual/perl-version:0
emerge -vD1 --backtrack=30 perl-core/Digest-SHA:0
emerge -vD1 --backtrack=30 virtual/perl-Digest-SHA:0
emerge -vD1 --backtrack=30 perl-core/Module-Load-Conditional:0
emerge -vD1 --backtrack=30 virtual/perl-Module-Load-Conditional:0
emerge -vD1 --backtrack=30 perl-core/Compress-Raw-Zlib:0
emerge -vD1 --backtrack=30 virtual/perl-Compress-Raw-Zlib:0
emerge -vD1 --backtrack=30 perl-core/ExtUtils-Install:0
emerge -vD1 --backtrack=30 virtual/perl-ExtUtils-Install:0
emerge -vD1 --backtrack=30 perl-core/IO:0
emerge -vD1 --backtrack=30 virtual/perl-IO:0
emerge -vD1 --backtrack=30 perl-core/Time-Local:0
emerge -vD1 --backtrack=30 virtual/perl-Time-Local:0
emerge -vD1 --backtrack=30 perl-core/Module-CoreList:0
emerge -vD1 --backtrack=30 virtual/perl-Module-CoreList:0
emerge -vD1 --backtrack=30 perl-core/Digest-MD5:0
emerge -vD1 --backtrack=30 virtual/perl-Digest-MD5:0
emerge -vD1 --backtrack=30 perl-core/JSON-PP:0
emerge -vD1 --backtrack=30 virtual/perl-JSON-PP:0
emerge -vD1 --backtrack=30 perl-core/ExtUtils-ParseXS:0
emerge -vD1 --backtrack=30 virtual/perl-ExtUtils-ParseXS:0
emerge -vD1 --backtrack=30 perl-core/File-Temp:0
emerge -vD1 --backtrack=30 virtual/perl-File-Temp:0
emerge -vD1 --backtrack=30 perl-core/Params-Check:0
emerge -vD1 --backtrack=30 virtual/perl-Params-Check:0
emerge -vD1 --backtrack=30 perl-core/Module-Metadata:0
emerge -vD1 --backtrack=30 virtual/perl-Module-Metadata:0
emerge -vD1 --backtrack=30 perl-core/Sys-Syslog:0
emerge -vD1 --backtrack=30 virtual/perl-Sys-Syslog:0
emerge -vD1 --backtrack=30 perl-core/IO-Compress:0
emerge -vD1 --backtrack=30 virtual/perl-IO-Compress:0
emerge -vD1 --backtrack=30 perl-core/Test-Harness:0
emerge -vD1 --backtrack=30 virtual/perl-Test-Harness:0

That’s all there is to it. :-)

Can Linux cope with 24 Hours of Happy?

I enjoyed Pharrell Williams’ feel-good songs in ‘Despicable Me‘ and its sequel, ‘Despicable Me 2‘. ‘Happy‘, a very catchy ditty he wrote for the sequel, also features in the World’s first 24-hour-long music video, ‘24 Hours of Happy‘, shot in and around Los Angeles and released on 21 November last year. The song is played a total of 360 times over the duration of the video, each 4-minute take featuring a different person or persons dancing (improvised) along streets, in petrol stations, through Union Station, in a church, around a school, in a moving school bus, around a supermarket, in a bowling alley, and so on. Each 4-minute performance was filmed in one take using Steadicam, and the location at the end of each take segues into the next take. You see the sun rise; you see the bright sunlight of the morning and the warm sunlight of the afternoon; you see the sun set; you see the twinkling city lights at night. The concept is simple yet brilliant.

Clips from some of the takes were used to create the 4-minute official music video for ‘Happy’, so you can watch that on YouTube to get a flavour of the takes, although it does not do justice to the full video.

Williams appears in a different take every hour on the hour, and a few other takes have celebrity cameos, but the vast majority of the participants are unknown extras of all ages, races, shapes, sizes and looks. To quote Williams talking to the Los Angeles Times: “We wanted all humanity in there, not just the model-types you might expect.” Some are good dancers, others not so good. But they all have one thing in common: they’re having fun, so they look good. The joy is infectious, and I found myself watching far longer than I would have expected, having to return to the site again and again. Half the fun is watching the bystanders.

When you open the ’24 Hours of Happy’ site, the take that was in progress at the current time of day starts playing from the beginning. However, you can drag the pointer around the clock dial and watch any take from the 24-hour period. There are also buttons you can click on to jump between takes or to jump to each take featuring Williams. The yellow on-screen controls can be made to disappear by not moving the mouse pointer for 5 seconds.

Still from 24 Hours of Happy, showing on-screen controls

Still from 24 Hours of Happy, showing on-screen controls

The Web site is well-designed and fun to use, so I was not surprised it was voted ‘Site of the Month‘ and ‘Site of the Year Users’ Choice‘ by AWWWARDS, and voted ‘Site of the Month‘ and ‘Site of the Year‘ by TheFWA.

It’s impossible to list them all, but a few of my favourite takes are:

01:36  Very perky woman with ponytail.
05:28  Jogger who has to keep pulling his shorts up!
08:24  Woman on roller skates.
09:52  Very cute little girl.
09:56  Woman with some groovy moves.
10:40  Woman in Union Station. Some of the bystanders are particularly amusing.
11:16  Man with cast on foot.
11:20  Boy with an Afro.
11:36  Three groovy old ladies.
11:44  Chubby guy with style.
12:36  Woman with some groovy moves.
13:32  Dancing couple in pink.
14:20  Two cool guys in dinner jackets inside and outside Union Station.
15:00  Pharrell Williams in a church with a gospel choir.
19:04  Woman with a lizard puppet. The lizard does the lip-synching!
19:36  Guy on stilts.
23:40  Woman with LED hula hoop (love it!).

If you want to start viewing a take made at a specific time of day, you can append the time to the URL, like so:

http://24hoursofhappy.com/09h53am

Obviously I think ’24 Hours of Happy’ is fabulous, but why am I discussing it in a blog predominantly about Linux? Because Firefox 27.0.1 (32-bit) running in Windows 8.1 (64-bit) on my new Acer Aspire XC-600 micro-tower PC (dual-core Intel Pentium G2030 @ 3 GHz & 3 MB cache, 4 GB DDR3 RAM) handles ’24 Hours of Happy’ at 720p with ease, but the story is very different on my main laptop running 64-bit Gentoo Linux with KDE (quad-core Intel Core i7 720QM @ 933 MHz & 6 MB cache, 4 GB DDR3 RAM). Both machines are on my home network, connected to the Internet via high-bandwidth broadband (FTTC).

On my laptop, the latest available versions of Firefox (27.0) and Opera (12.16_p1860-r1) for Gentoo, both 64-bit, do not even complete loading the ’24 Hours of Happy’ site: the black progress bar at the bottom of the home page stops about 7/8th of the way across the page and the KDE Network Monitor widget shows there is no network activity. Clearing Firefox’s Web content cache or increasing the cache’s size to 1 GB make no difference. Konqueror 4.12.2 (configured to use the WebKit browser engine rather than the KHTML engine) loads the site and plays it quite well at 720p to start with, but eventually video becomes choppy and I notice a lot of spawned kio_http processes. The KDE Network Monitor widget shows a continuous 3600 Kib/s data stream, which does not stop when I exit Konqueror. Numerous kio_http processes are spawned and remain after I exit Konqueror, and the 3600 KiB/s activity on the network only ceases when I kill all the kio_http processes. The number of spawned kio_http processes increases if I drag the pointer around the clock to select different takes, and the page just displays ‘LOADING’ ad infinitum if I do this several times. To be fair, if I do this a lot in Firefox running in Windows 8.1, I can get Firefox to stall too. I thought I’d try a lightweight browser and installed NetSurf (3.0-r1), but that couldn’t even render the title on the home page, let alone begin to load the video.

So, does ’24 Hours of Happy’ play nicely in your Linux installation? If it does, what hardware, distribution, desktop environment, browser and quality (360p, 480p, 720p or 1080p) are you using?

KDE Connect – Link your Android device to your KDE desktop

KDE Connect app icon on my Samsung Galaxy Note II

KDE Connect app icon on my Samsung Galaxy Note II

KDE Connect is a nice tool that links your Android phone or tablet seamlessly via WiFi to KDE on your PC (the latter can be connected via WiFi or cable to the network). It allows your KDE desktop to receive notifications, files and media player commands from your Android device. The available KDE Connect plug-ins are:

Battery report
Periodically report battery status

Clipboard sync
Share the clipboard content

Multimedia remote controls
Control audio/video from your phone
(pause; first track; previous track; next track; last track; change volume)

Notification sync
Access your notification from other devices

Ping
Send and receive pings

Telephony notifier
Send notifications from SMS and calls

You will need to install the Android KDE Connect application on your Android device, and the Linux KDE Connect application on your PC.

Install the KDE Connect app on your Android device from the Google Play Store. You will then see the KDE Connect icon on the apps screen of your Android device.

For Gentoo users an ebuild for KDE Connect is available in the Gentoo KDE team’s testing overlay, so here are the instructions on how to install KDE Connect on your PC from there.

Firstly, mask the KDE overlay so that none of the packages in it interferes with the KDE software you installed from the main Portage tree:

# echo "*/*::kde" >> /etc/portage/package.mask

Then unmask the KDE Connect package in the KDE overlay:

# echo "kde-misc/kdeconnect" >> /etc/portage/package.unmask

N.B. If /etc/portage/package.mask is a directory rather than a file (either is possible) in your installation, and if /etc/portage/package.unmask is a directory rather than a file (either is possible) in your installation, use the following commands instead of the above two commands:

# echo "*/*::kde" > /etc/portage/package.mask/kde_overlay
# echo "kde-misc/kdeconnect" > /etc/portage/package.unmask/kdeconnect

Now add the KDE overlay and merge the package:

# layman -a kde
# emerge kdeconnect

If a firewall is running on your PC, you will need to configure it to allow tcp and udp traffic via a specific range of ports (1714 to 1764). I have UFW running on my main laptop, so in my case I used the following commands:

# ufw allow proto tcp to any port 1714:1764
# ufw allow proto udp to any port 1714:1764

The rules should look like this:

# ufw status verbose | grep 1714
1714:1764/tcp ALLOW IN Anywhere
1714:1764/udp ALLOW IN Anywhere
1714:1764/tcp ALLOW IN Anywhere (v6)
1714:1764/udp ALLOW IN Anywhere (v6)

If you have the KConfig Module kcm_ufw installed on your PC then you can instead use System Settings > Firewall to add the UFW rules via the KDE GUI.

By the way, to check which KConfig modules are installed on your PC you can use the following command under your user account:

$ kcmshell4 --list

Using KDE Connect is not difficult, so I will leave you to play with it. Obviously make sure WiFi is enabled on your Android device, and that it and your PC are connected to the same network. Tap on the KDE Connect icon on your Android device to launch the app, and you should see your PC’s name listed under CONNECTED DEVICES. Tap on the PC name and you should see the following screen:

KDE Connect screen

KDE Connect screen

If you tap on ‘Send ping’, the KDE Notification widget on the KDE System Tray should pop up a notification.

You can see what KDE Connect plug-ins are available, and select/deselect them:

KDE Connect plugins

KDE Connect plugins

KDE Connect also enables you to use your Android device as a remote control for media players running on your PC. When you launch a media player in KDE its name will appear in a list of selectable players in KDE Connect, and the name of the track currently playing will also be displayed:

KDE Connect - Remote control

KDE Connect - Remote control

When you select a file on your Android device and tap the Share icon, KDE Connect will be one of the options displayed on the ‘Share via’ menu. This is a handy way to send files from your Android device to your PC. The KDE Notification widget on your PC will notify you when the file has been transferred to ~/Desktop/ on your PC:

KDE on your PC notifies you when a file has been sent via KDE Connect

KDE on your PC notifies you a file has been sent via KDE Connect

You should also get notifications on your KDE desktop when someone phones or sends you an SMS.

Kudos and many thanks to the people responsible for KDE Connect. KDE is already a superb desktop environment, and with the addition of KDE Connect it is better still.

Dropbox revisited

In a previous post I explained how I installed Kfilebox, an unofficial KDE front-end for Dropbox. However, development of Kfilebox appears to have stopped, as the original author posted the following recently on a blog:

“I have stopped working on kfilebox after some updates in dropbox. Shortly: there is no way to get recent changed files, no more access to config options, cant configure it.”

Nevertheless I continued using Kfilebox. However, after a few days the Kfilebox icon stopped appearing in the KDE System Tray, and clicking on ‘Show hidden icons’ > ‘Kfilebox’ on the Panel displayed “The Dropbox daemon isn’t running” in the pop-up menu. Also, if I clicked on the hidden Kfilebox icon and selected ‘Preferences…’ the Dropbox folder field was empty and I had to keep re-entering the location of the Dropbox folder. So I decided to uninstall Kfilebox and try using Dropbox directly with KDE. I performed the steps listed below.

  1. Uninstall Kfilebox:

    # emerge -C kfilebox

  2. Remove any associated directories and files that might be left over:

    # rm -rf /home/fitzcarraldo/.dropbox
    # rm -rf /home/fitzcarraldo/.dropbox-dist
    # rm /home/fitzcarraldo/.kde4/share/config/kfileboxrc

  3. Install Dropbox:

    # emerge dropbox

  4. Do not edit /etc/conf.d/dropbox and do not configure Gentoo to launch the Dropbox daemon at start-up (i.e. do not add /etc/init.d/dropbox to the default runlevel). Instead configure KDE to launch the daemon when logging-in to KDE:
    1. Kickoff > System Settings > Startup and Shutdown
    2. Click on ‘Autostart’ in the left pane.
    3. Click on the ‘Add Script…’ button on the right side of the window.
    4. Enter the location of the Dropbox daemon in the box in the pop-up window. I entered “/opt/dropbox/dropboxd” (without the quotes) in the box and clicked ‘OK’.
  5. Run Dropbox for the first time and configure the local installation:
    1. Open a Dolphin window and browse to the directory containing the daemon (/opt/dropbox/) and double-click on dropboxd to launch the daemon.
    2. The Dropbox set-up window will pop-up and it should be obvious what to do from there onwards. As I already had a Dropbox account I selected ‘I already have a Dropbox account’ and clicked ‘Next’, I then entered my e-mail address, my Dropbox password and my computer’s name in the boxes and clicked ‘Next’. I left the default free 2 GB option selected and clicked ‘Next’. I left the default set-up ‘Typical’ selected and clicked ‘Install’. I read the introductory information displayed in the next couple of windows and clicked ‘Next’. I clicked ‘Finish’ in the final ‘That’s it!’ window.
  6. A Dropbox icon then appears in the System Tray on the Panel and synchronises with the Dropbox directory on the remote Dropbox server.

Now if I click on the Dropbox icon in the System Tray, the Dropbox directory window pops up. If I right-click on the icon in the System Tray, a menu pops-up with the expected Dropbox options.

So there was no need to use Kfilebox after all, as using the Dropbox daemon directly is just as user-friendly.

Installing Dropbox in Gentoo running KDE

kfilebox
I had never used Dropbox before and had no intention of doing so, but today a work colleague sent me some large files via Dropbox so I was forced to sign up. I tried to install Dropbox on my main laptop running Gentoo Linux and KDE but, for a well-known application, I had a surprising amount of trouble, hence this blog post.

To begin with, I found the following Dropbox-related packages:

# eix dropbox
* gnome-extra/nautilus-dropbox
Available versions: (~)0.6.9 (~)0.7.0 0.7.1 (~)1.4.0 {debug}
Homepage: http://www.dropbox.com/
Description: Store, Sync and Share Files Online
.
* net-misc/dropbox
Available versions: 1.2.48-r1^ms (~)1.2.51-r2^ms (~)1.4.3-r1^ms (~)1.4.7-r1^ms (~)1.4.7-r2^ms (~)1.4.17^ms (~)1.4.23^ms (~)1.6.16^ms {X +librsync-bundled}
Homepage: http://dropbox.com/
Description: Dropbox daemon (pretends to be GUI-less)
.
* net-misc/dropbox-cli
Available versions: 1 1-r1 {PYTHON_TARGETS="python2_6 python2_7"}
Homepage: http://www.dropbox.com/
Description: Cli interface for dropbox daemon (python)
.
* xfce-extra/thunar-dropbox [1]
Available versions: [m](~)0.2.0
Homepage: http://www.softwarebakery.com/maato/thunar-dropbox.html
Description: Plugin for Thunar that adds context-menu items for Dropbox
.
[1] "sabayon" /var/lib/layman/sabayon
.
Found 4 matches.

But I don’t have GNOME or Xfce installed on my main laptop, so the first and last packages were of no interest. A quick search on the Web turned up Kfilebox, which seemed to be exactly what I needed. I was pleased to find that the package is in the main Portage tree:

# eix kfilebox
* kde-misc/kfilebox
Available versions: (4) (~)0.4.8 (~)0.4.9
{LINGUAS="ar br cs de el es fr gl it lt nl pl pt ru si tr zh zh_CN"}
Homepage: http://kdropbox.deuteros.es/
Description: KDE dropbox client

So I installed kfilebox, dropbox and dropbox-cli, thinking I would need them all. Then, before doing anything else, I surfed to the Dropbox Web site and signed up for an account.

I launched Konsole and entered the command kfilebox. A window popped-up telling me that the Dropbox Daemon was being downloaded, then another window popped up offering me two options/buttons: ‘Run gtk based installer’ and ‘Or simply link account’. I clicked on the latter, thinking that was all I needed to do as I had already signed up for an account via the Dropbox Web site. But a Dropbox icon did not appear in the Panel, nor did Dolphin show a Dropbox folder icon in my home directory, and the KDE Notifications widget kept popping up notification after notification from Kfilebox to “Please visit url to link to this machine”. The trouble was that clicking on the apparent link in the notifications did nothing.

The directories .dropbox and .dropbox-dist existed in my home directory, and the contents of /home/fitzcarraldo/.kde4/share/config/kfileboxrc were as follows:

[General]
AutoStart=true
Browser=rekonq
DropboxDir=/home/fitzcarraldo/.dropbox-dist/
FileManager=dolphin
GtkUiDisabled=true
IconSet=default
ShowNotifications=true
StartDaemon=true

As the rekonq Web browser is not installed on this laptop, I edited the file and changed Browser=rekonq to Browser=firefox then rebooted, but it made no difference.

So I uninstalled everything:

# emerge -C kfilebox dropbox dropbox-cli
# rm -rf /home/fitzcarraldo/.dropbox
# rm -rf /home/fitzcarraldo/.dropbox-dist
# rm /home/fitzcarraldo/.kde4/share/config/kfileboxrc

then rebooted and reinstalled only Kfilebox:

# emerge kfilebox

I then launched Konsole and entered the command kfilebox. The pop-up window appeared notifying me that the Dropbox Daemon was being downloaded, followed by the pop-up window offering me the choice of running the gtk-based installer or simply linking the account. This time I chose the option to run the gtk-based installer and just followed the intuitive instructions in the various pop-up windows that followed, one of which offered to create a new Dropbox account or to link to an existing Dropbox account. As I wanted to do the latter I entered my e-mail address and Dropbox password, a Dropbox icon then appeared on the Panel and a Dropbox folder icon is now visible in Dolphin.

I checked the contents of ~/.kde4/share/config/kfileboxrc and they were the same as listed above, so I edited the file to replace rekonq with firefox, although I’m not sure yet what (if anything) that does, as Dropbox is new to me and I’m still learning. Anyway, the important thing is that I could now click on the ‘View folder’ button in an e-mail sent to me by a colleague and the files uploaded by my colleague were automatically downloaded into the ~/Dropbox directory.

EDIT May 30, 2013: Kfilebox is no longer in development and has started playing up. However, I found out how to install Dropbox directly and use it with KDE, and it’s just as user-friendly as Kfilebox. See my post Dropbox revisited for how to install Dropbox directly.

Switching the display quickly between a laptop monitor and an external monitor or projector in Linux

laptop_with_external_monitor_and_keyboardI connect my laptop to an external keyboard and an external monitor or projector in various offices and at home, and each of the monitors has a different resolution. Fn-F3 on my laptop keyboard allows me to toggle between monitors, but I want more control (including the ability to specify the resolution of the external display). Now, I find the GPU manufacturer’s application and the Desktop Environment’s GUI for switching monitors and changing screen resolution rather cumbersome, so I wanted an icon on the Desktop that I could double-click to switch monitors without having to enter the root user’s password and fiddle around too much. So I decided to create some simple Bash scripts and associated Desktop Config files with nice-looking icons on the desktop, which I can launch easily and quickly by double-clicking. Obviously the resolutions are limited to the range of resolutions supported by the GPU and external monitor.

The suite of Desktop Config files I created have self-explanatory names:

$ cd ~/Desktop
$ ls -1 Switch*
Switch_OFF_laptop_monitor_if_external_monitor_is_connected
Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto
Switch_ON_laptop_monitor_and_external_monitor
Switch_ON_laptop_monitor_and_switch_off_external_monitor
$ ls -1 Toggle*
Toggle_display

The difference between Switch_OFF_laptop_monitor_if_external_monitor_is_connected and Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto is that the former prompts for the resolution of the external monitor whereas the latter tries to find the resolution automatically. I have both because I have found that, for some external display devices (e.g. projectors), it is handy to have the ability to specify the resolution manually.

Switch off the laptop monitor if an external monitor is connected (find resolution automatically)

The Desktop Config file I double-click the most is ~/Desktop/Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto, and it contains the following text:

[Desktop Entry]
Comment[en_GB]=switch off laptop monitor if external monitor is connected auto
Comment=switch off laptop monitor if external monitor is connected auto
Exec=sh /home/fitzcarraldo/switch_off_laptop_monitor_if_external_monitor_is_connected_auto.sh
GenericName[en_GB]=Switch off laptop monitor if external monitor is connected auto
GenericName=Switch off laptop monitor if external monitor is connected auto
Icon=/home/fitzcarraldo/Pictures/Icons/display.png
MimeType=
Name[en_GB]=Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto
Name=Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=

The Bash script it launches, ~/switch_off_laptop_monitor_if_external_monitor_is_connected_auto.sh, contains the following code:

#!/bin/bash
if xrandr -q | grep "CRT1 connected"; then
  xrandr --output LVDS --off
  xrandr --output CRT1 --off
  xrandr --output CRT1 --auto
else
  xrandr --output CRT1 --off
  xrandr --output LVDS --off
  xrandr --output LVDS --mode 1920x1080
# 1920x1080 is the native resolution of my laptop monitor
fi

Don’t forget to make them executable:

$ chmod +x /home/fitzcarraldo/Desktop/Switch_OFF_laptop_monitor_if_external_monitor_is_connected_auto
$ chmod +x /home/fitzcarraldo/switch_off_laptop_monitor_if_external_monitor_is_connected_auto.sh

If you’re wondering how I knew I had to specify ‘CRT1′ and ‘LVDS’ in the Bash script, I used the xrandr command to find out what names the GPU gives the monitors:

$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 1920 x 1920
LVDS connected (normal left inverted right x axis y axis)
1920x1080 60.0 +
1680x1050 60.0
1400x1050 60.0
1600x900 60.0
1280x1024 60.0
1440x900 60.0
1280x960 60.0
1280x768 60.0
1280x720 60.0
1024x768 60.0
1024x600 60.0
800x600 60.0
800x480 60.0
640x480 60.0
DFP1 disconnected (normal left inverted right x axis y axis)
CRT1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 476mm x 268mm
1920x1080 60.0*+
1280x1024 75.0 60.0
1280x960 60.0
1280x800 59.8
1152x864 75.0
1280x720 60.0
1024x768 75.0 70.1 60.0
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 67.0 59.9

Switch off the laptop monitor if an external monitor is connected (enter resolution)

The Desktop Config file I double-click is ~/Desktop/Switch_OFF_laptop_monitor_if_external_monitor_is_connected, and it contains the following text:

[Desktop Entry]
Comment[en_GB]=switch off laptop monitor if external monitor is connected
Comment=switch off laptop monitor if external monitor is connected
Exec=sh /home/fitzcarraldo/System_Administration/switch_off_laptop_monitor_if_external_monitor_is_connected.sh
GenericName[en_GB]=Switch off laptop monitor if external monitor is connected
GenericName=Switch off laptop monitor if external monitor is connected
Icon=/home/fitzcarraldo/Pictures/Icons/display.png
MimeType=
Name[en_GB]=Switch_OFF_laptop_monitor_if_external_monitor_is_connected
Name=Switch_OFF_laptop_monitor_if_external_monitor_is_connected
Path=
StartupNotify=true
Terminal=true
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=

The Bash script it launches, ~/switch_off_laptop_monitor_if_external_monitor_is_connected.sh, contains the following code:

#!/bin/bash
if xrandr -q | grep "CRT1 connected"; then
echo -n "Enter resolution width of external monitor (hint 1920 Doha, 1440 home): "
read EXTERNAL_WIDTH
echo -n "Enter resoluton height of external monitor (hint 1080 Doha, 900 home): "
read EXTERNAL_HEIGHT
  xrandr --output LVDS --off
  xrandr --output CRT1 --off
  xrandr --output CRT1 --mode $EXTERNAL_WIDTH"x"$EXTERNAL_HEIGHT
else
  xrandr --output CRT1 --off
  xrandr --output LVDS --off
  xrandr --output LVDS --mode 1920x1080
# 1920x1080 is the native resolution of my laptop monitor
fi

Don’t forget to make them executable:

$ chmod +x /home/fitzcarraldo/Desktop/Switch_OFF_laptop_monitor_if_external_monitor_is_connected
$ chmod +x /home/fitzcarraldo/switch_off_laptop_monitor_if_external_monitor_is_connected.sh

Switch on the laptop monitor and external monitor simultaneously

I don’t need to use this one much, only when I am using an external monitor but suddenly want to use the laptop’s built-in Webcam and so have to open fully the laptop’s lid. The file ~/Desktop/Switch_ON_laptop_monitor_and_external_monitor contains the following text:

[Desktop Entry]
Comment[en_GB]=switch_ON_laptop_monitor_and_external_monitor
Comment=switch_ON_laptop_monitor_and_external_monitor
Exec=sh /home/fitzcarraldo/switch_on_laptop_monitor_and_external_monitor.sh
GenericName[en_GB]=Switch_ON_laptop_monitor_and_external_monitor
GenericName=Switch_ON_laptop_monitor_and_external_monitor
Icon=/home/fitzcarraldo/Pictures/Icons/display.png
MimeType=
Name[en_GB]=Switch_ON_laptop_monitor_and_external_monitor
Name=Switch_ON_laptop_monitor_and_external_monitor
Path=
StartupNotify=true
Terminal=true
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=

and the Bash script it calls, ~/switch_on_laptop_monitor_and_external_monitor.sh, contains the following code:

#!/bin/bash
if xrandr -q | grep "CRT1 connected"; then
  echo "Note that the resolution specified must be the same for both monitors, and must be achievable on both monitors."
  echo -n "Enter resolution width of external monitor (hint 1920 office, 1440 home): "
  read EXTERNAL_WIDTH
  echo -n "Enter resoluton height of external monitor (hint 1080 office, 900 home): "
  read EXTERNAL_HEIGHT
  #xrandr --output LVDS --off
  xrandr --output LVDS --mode $EXTERNAL_WIDTH"x"$EXTERNAL_HEIGHT
  xrandr --output CRT1 --off
  xrandr --output CRT1 --mode $EXTERNAL_WIDTH"x"$EXTERNAL_HEIGHT
else
  xrandr --output CRT1 --off
  xrandr --output LVDS --off
  xrandr --output LVDS --mode 1920x1080
# 1920x1080 is the native resolution of my laptop monitor
fi

Don’t forget to make them executable:

$ chmod +x /home/fitzcarraldo/Desktop/Switch_ON_laptop_monitor_and_external_monitor
$ chmod +x /home/fitzcarraldo/switch_on_laptop_monitor_and_external_monitor.sh

Switch on the laptop monitor and switch off an external monitor

I don’t need to use this one much either, given that the display mode reverts to the laptop monitor after I reboot or shutdown/power-up the laptop. The file ~/Desktop/Switch_ON_laptop_monitor_and_external_monitor contains the following text:

[Desktop Entry]
Comment[en_GB]=switch on laptop monitor and switch off external monitor
Comment=switch on laptop monitor and switch off external monitor
Exec=sh /home/fitzcarraldo/switch_on_laptop_monitor_and_switch_off_external_monitor.sh
GenericName[en_GB]=Switch on laptop monitor and switch off external monitor
GenericName=Switch on laptop monitor and switch off external monitor
Icon=computer-laptop
MimeType=
Name[en_GB]=Switch_ON_laptop_monitor_and_switch_off_external_monitor
Name=Switch_ON_laptop_monitor_and_switch_off_external_monitor
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=
X-KDE-SubstituteUID=false
X-KDE-Username=

The Bash script it launches, ~/switch_on_laptop_monitor_and_switch_off_external_monitor.sh, contains the following code:

#!/bin/bash
xrandr --output CRT1 --off
xrandr --output LVDS --auto
xrandr --output LVDS --mode 1920x1080
# 1920x1080 is the native resolution of my laptop monitor

I did also create a fifth Desktop Config file and associated Bash script, to toggle between the three modes (laptop monitor only > both monitors > external monitor only) rather than having to double-click three different icons. But, to be honest, it’s quicker and easier to have the three icons and double-click on the one I want rather than toggling through three display modes. Anyway, in case you are interested, the Desktop Config file ~/Desktop/Toggle_Display contains the follow text:

[Desktop Entry]
Comment[en_GB]=Toggle between laptop monitor, external monitor and both
Comment=Toggle between laptop monitor, external monitor and both
Exec=sh /home/fitzcarraldo/toggle_display.sh
GenericName[en_GB]=Toggle between laptop monitor, external monitor and both
GenericName=Toggle between laptop monitor, external monitor and both
Icon=video-display
MimeType=
Name[en_GB]=Toggle_display
Name=Toggle_display
Path=
StartupNotify=false
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=

and the Bash script it launches, ~/switch_on_laptop_monitor_and_external_monitor.sh, contains the following code:

#!/bin/sh

# Using the xrandr command I found that the two video outputs from my laptop are named LVDS
# (the internal display) and CRT1 (the external display driven by the laptop's VGA socket).
# My external monitor at home has a resolution of 1440x900.

CONNECTED=`xrandr | grep -i ' connected' | grep LVDS | awk '{print $1}'`
CONNECTED="${CONNECTED} `xrandr | grep -i ' connected' | grep CRT | awk '{print $1}'`"

ENABLED=`awk '{print;exit}' ~/displays_enabled 2>/dev/null`

if [ "$CONNECTED" = "LVDS" -o "$CONNECTED" = "LVDS " -o "$CONNECTED" = " LVDS" ]; then
        # Only the internal display is connected, so don't do anything.
        echo "LVDS" > ~/displays_enabled
        ENABLED="LVDS"
        xrandr --output CRT1 --off
        xrandr --output LVDS --off
        xrandr --output LVDS --auto
        exit 0
elif [ "$CONNECTED" = "LVDS CRT1" ]; then
        # Both the internal and external displays are connected, so let's toggle
        # LVDS > LVDS,CRT1 > CRT1

        EXTERNALRES=`xrandr | awk 'c&&c--;/ connected/{c=1}' | awk '{print $1}' | grep 1440x900`
        if [ "$ENABLED" = "LVDS" ]; then
        # Switching on both displays.
                xrandr --output LVDS --off
                if [ "$EXTERNALRES" = "1440x900" ]; then
                         xrandr --output LVDS --mode 1440x900
                         xrandr --output CRT1 --off
                         xrandr --output CRT1 --auto
                else
                         xrandr --output LVDS --auto
                         xrandr --output CRT1 --off
                         xrandr --output CRT1 --auto
                fi
                ENABLED="LVDS CRT1"
                echo "LVDS CRT1" > ~/displays_enabled
        elif [ "$ENABLED" = "LVDS CRT1" ]; then
        # Switching on only external display.
                xrandr --output LVDS --off
                xrandr --output CRT1 --off
                xrandr --output CRT1 --auto
                ENABLED="CRT1"
                echo "CRT1" > ~/displays_enabled
        else
        # Switching on only internal display.
                xrandr --output CRT1 --off
                xrandr --output LVDS --off
                xrandr --output LVDS --auto
                ENABLED="LVDS"
                echo "LVDS" > ~/displays_enabled
        fi
fi

As I use KDE, I also used System Settings > Shortcuts and Gestures | Custom Shortcuts to create a keyboard shortcut which I named ‘Toggle display’, with Meta+P as Trigger and sh ~/toggle_display.sh as Action, but I tend to use the mouse rather than the keyboard in any case.

By the way, you might think some of the xrandr commands in the above Bash scripts are redundant. You would be correct in thinking that, but in practice I found that the displays did not switch if I didn’t include the additional commands shown (due to a bug in xrandr, perhaps?). Even then, when I switch to an external monitor, occasionally the screen resolution is slightly too big or too small, so I placed the icons at the top left of the desktop so that they are always accessible and I can just double-click on the same icon again if necessary. As I’m using KDE, I placed a Folder View Plasmoid for ~/Desktop/ at the top left of the desktop, as you can see in the screenshot.

Desktop showing icons for switching between monitors

Footnote

I’ve been using the above method of switching between displays for a couple of years now with an AMD ATI GPU. It works nicely and suits my needs perfectly. AMD has supported xrandr since 2008 (see Ref. 1), whereas NVIDIA only began to support xrandr last year (see Ref. 2) so I’m not sure how well these scripts would work with NVIDIA GPUs.

Ref. 1: AMD Catalyst 8.9 Gets WINE Fix, RandR 1.2 Support, September 18, 2008
Ref. 2: NVIDIA’s 302 Linux Driver Finally Has RandR 1.2/1.3, May 2, 2012

Setting the wireless regulatory domain in Linux on your laptop

I travel internationally and want to make sure that my laptop uses the legal wireless networking frequencies in the country I am visiting. In Linux, CRDA (Central Regulatory Domain Agent) is the udev helper used to communicate between userspace and the kernel, and it enables you to view and alter the wireless regulatory domain your kernel uses. For more information see the Regulatory page on the Linux Wireless Wiki site.

CFG80211 is the Linux wireless LAN (802.11) configuration API. The kernel on my main laptop has the following configuration settings relating to CFG80211:

# cat /usr/src/linux/.config | grep CFG80211
CONFIG_CFG80211=m
# CONFIG_CFG80211_DEVELOPER_WARNINGS is not set
# CONFIG_CFG80211_REG_DEBUG is not set
CONFIG_CFG80211_DEFAULT_PS=y
# CONFIG_CFG80211_DEBUGFS is not set
# CONFIG_CFG80211_INTERNAL_REGDB is not set
CONFIG_CFG80211_WEXT=y

and the cfg80211 module is loaded:

# lsmod | grep cfg80211
cfg80211 145747 3 iwlwifi,mac80211,iwldvm

I have the package crda installed, and I have the following udev rule file /etc/udev/rules.d/regulatory.rules to allow the kernel to communicate with userspace:

KERNEL=="regulatory*", ACTION=="change", SUBSYSTEM=="platform", RUN+="/sbin/crda"

So, how do you check which wireless regulatory domain your kernel is currently using, and switch to another domain if necessary? These tasks are performed using the iw command. You’ll need to install the package iw if it is not already installed.

To see the regulatory domain your laptop is using now, enter the following command as root user:

iw reg get

When I use the above command on my laptop after start-up, I normally see the following:

# iw reg get
country 00:
(2402 - 2472 @ 40), (3, 20)
(2457 - 2482 @ 20), (3, 20), PASSIVE-SCAN, NO-IBSS
(2474 - 2494 @ 20), (3, 20), NO-OFDM, PASSIVE-SCAN, NO-IBSS
(5170 - 5250 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS
(5735 - 5835 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS

The country code 00 is not the code of the country I am in at present. To tell the kernel which wireless regulatory domain you wish to use, enter the following command as root user:

iw reg set ISO_3166-1_alpha-2

where ISO_3166-1_alpha-2 is the 2-character code for the country you are in. You can find the list of ISO 3166-1 alpha-2 codes on the Wikipedia page ISO 3166-1 alpha-2.

For example, if I were in the UK then I would enter the following command:

# iw reg set GB

and the regulatory domain would then be reported like this:

# iw reg get
country GB:
(2402 - 2482 @ 40), (N/A, 20)
(5170 - 5250 @ 40), (N/A, 20)
(5250 - 5330 @ 40), (N/A, 20), DFS
(5490 - 5710 @ 40), (N/A, 27), DFS

It is not a big deal to use the command line, but I wanted to make it even easier. I’m using KDE on my main laptop, so I created a Desktop Configuration File /home/fitzcarraldo/Desktop/Set_wireless_regulatory_domain containing the following:

[Desktop Entry]
Comment[en_GB]=
Comment=
Exec=/home/fitzcarraldo/iw_reg.sh
GenericName[en_GB]=Set wireless regulatory domain
GenericName=Set wireless regulatory domain
Icon=/home/fitzcarraldo/national-flags-icon.png
MimeType=
Name[en_GB]=Set_wireless_regulatory_domain
Name=Set_wireless_regulatory_domain
Path=
StartupNotify=true
Terminal=true
TerminalOptions=\s--noclose
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=

and gave it the following file permissions:

# chmod 744 /home/fitzcarraldo/Desktop/Set_wireless_regulatory_domain
# ls -la /home/fitzcarraldo/Desktop/Set_wireless_regulatory_domain
-rwxr--r-- 1 fitzcarraldo users 496 Jan 15 21:53 /home/fitzcarraldo/Desktop/Set_wireless_regulatory_domain

I used a search engine to find a nice PNG icon consisting of several overlapping national flags, and saved it with the file name name national-flags-icon.png in my home directory.

I created a Bash shell script /home/fitzcarraldo/iw_reg.sh containing the following:

#!/bin/bash
echo "First you need to enter the password of your user account..."
sudo echo ""
echo "The ISO 3166-1 alpha-2 codes are listed on Web page https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2"
echo ""
echo "The current wireless regulatory domain is set as: "
echo ""
sudo iw reg get
echo ""
echo -n "Enter the ISO 3166-1 alpha-2 code (upper case) for the country you are in now, and press ENTER: "
read REGULATORYDOMAIN
sudo iw reg set $REGULATORYDOMAIN
echo ""
echo "The current wireless regulatory domain is now set as: "
echo ""
sudo iw reg get
echo ""
echo "All done. You can close this window."

and gave it the following file permissions:

# chmod 744 /home/fitzcarraldo/iw_reg.sh
# ls -la /home/fitzcarraldo/iw_reg.sh
-rwxr--r-- 1 fitzcarraldo users 632 Jan 15 21:33 /home/fitzcarraldo/iw_reg.sh

Now, if I double-click on the icon for Set_wireless_regulatory_domain on my desktop, a Konsole window pops up with a prompt for me to enter my user account password. When I enter my password the window displays the current wireless regulatory domain the kernel is using and prompts me to enter the 2-character code for the regulatory domain I wish to use instead. When I enter the country code the window displays the new regulatory domain, as shown in the sample below.


First you need to enter the password of your user account...
Password:

The ISO 3166-1 alpha-2 codes are listed on Web page https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2

The current wireless regulatory domain is set as:

country SA:
(2402 - 2482 @ 40), (N/A, 20)
(5170 - 5250 @ 20), (3, 23)
(5250 - 5330 @ 20), (3, 23), DFS
(5735 - 5835 @ 20), (3, 30)

Enter the ISO 3166-1 alpha-2 code (upper case) for the country you are in now, and press ENTER: GB

The current wireless regulatory domain is now set as:

country GB:
(2402 - 2482 @ 40), (N/A, 20)
(5170 - 5250 @ 40), (N/A, 20)
(5250 - 5330 @ 40), (N/A, 20), DFS
(5490 - 5710 @ 40), (N/A, 27), DFS

All done. You can close this window.

The task of viewing and changing the regulatory domain after start-up is now very easy for me. The only thing that would be easier than this would be if Linux could detect automatically which country I’m in and set the regulatory domain automatically.

Converting ape music files to mp3 in Linux

I had a file in the lossless ape (Monkey’s Audio) file format, and wanted to convert it to a .mp3 file so that I could play it on my portable mp3 player. As is usual in Linux, several alternative solutions exist, and I thought I’d try three of them for fun: shntool, ffmpeg and KDE’s Konvertible (Konvertible is a GUI for ffmpeg).

I already had ffmpeg and Konvertible installed, but not shntool. So first I installed shntool and the Monkey’s Audio codecs it uses:

# emerge media-sound/mac
# emerge media-sound/shntool

Here are the details of these two installed packages:

# eix -I shntool
[I] media-sound/shntool
Available versions: 3.0.10-r1 {alac flac mac shorten sox wavpack}
Installed versions: 3.0.10-r1(08:11:30 19/12/12)(flac -alac -mac -shorten -sox -wavpack)
Homepage: http://www.etree.org/shnutils/shntool/
Description: A multi-purpose WAVE data processing and reporting utility

# eix -I media-sound/mac
[I] media-sound/mac
Available versions: 3.99.4.5.7-r1^m {mmx static-libs}
Installed versions: 3.99.4.5.7-r1^m(07:52:12 19/12/12)(mmx -static-libs)
Homepage: http://etree.org/shnutils/shntool/
Description: Monkey's Audio Codecs

Then I used the following command to convert the file My Band 1971 CoolSounds.ape to mp3:

$ shntool conv -i ape -o 'cust ext=mp3 lame - %f' My\ Band\ 1971\ CoolSounds.ape
Converting [My Band 1971 CoolSounds.ape] (59:15.39) --> [My Band 1971 CoolSounds.mp3] : 100% OK
$

The KDE utility Konvertible was also able to convert it. I double-clicked on the file My Band 1971 CoolSounds.ape in Dolphin to launch Konvertible, selected libmp3lame in the ‘Codec:’ drop-down picklist, 192.00 kbits/s in the ‘Bitrate:’ drop-down picklist, clicked on the folder icon and selected /home/fitzcarraldo as the destination directory, and finally clicked ‘Convert’.

The mp3 files created by shntool and Konvertible were of different sizes:

File created by Konvertible:

$ file My\ Band\ 1971\ CoolSounds.mp3
My Band 1971 CoolSounds.mp3: Audio file with ID3 version 2.4.0, contains: MPEG ADTS, layer III, v1, 192 kbps, 44.1 kHz, Stereo
$ ls -la My\ Band\ 1971\ CoolSounds.mp3
-rw-r--r-- 1 fitzcarraldo users 85334024 Dec 19 08:11 My Band 1971 CoolSounds.mp3
$

File created by shntool:

$ file My\ Band\ 1971\ CoolSounds.mp3
My Band 1971 CoolSounds.mp3: MPEG ADTS, layer III, v1, 128 kbps, 44.1 kHz, JntStereo
$ ls -la My\ Band\ 1971\ CoolSounds.mp3
-rw-r--r-- 1 fitzcarraldo users 56889259 Dec 19 08:29 My Band 1971 CoolSounds.mp3
$

So I added the bitrate to the shntool command:

$ shntool conv -i ape -o 'cust ext=mp3 lame -b 192 - %f' My\ Band\ 1971\ CoolSounds.ape
Converting [My Band 1971 CoolSounds.ape] (59:15.39) --> [My Band 1971 CoolSounds.mp3] : 100% OK
$

and this time the mp3 file created by shntool is comparable to the mp3 file created by Konvertible:

$ file My\ Band\ 1971\ CoolSounds.mp3
My Band 1971 CoolSounds.mp3: MPEG ADTS, layer III, v1, 192 kbps, 44.1 kHz, JntStereo
$ ls -la My\ Band\ 1971\ CoolSounds.mp3
-rw-r--r-- 1 fitzcarraldo users 85333889 Dec 19 08:56 My Band 1971 CoolSounds.mp3
$

The ffmpeg command to do the same thing is:

$ ffmpeg -i My\ Band\ 1971\ CoolSounds.ape -ar 44100 -ab 192000 out.mp3
ffmpeg version 0.10.6 Copyright (c) 2000-2012 the FFmpeg developers
built on Nov 26 2012 07:06:40 with gcc 4.6.3
configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -march=native -pipe' --extra-cflags='-O2 -march=native -pipe' --extra-cxxflags='-O2 -march=native -pipe' --disable-static --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --disable-stripping --disable-debug --disable-doc --disable-vaapi --disable-vdpau --enable-runtime-cpudetect --enable-gnutls --enable-libmp3lame --enable-libvo-aacenc --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-libfaac --enable-nonfree --enable-libdc1394 --enable-openal --disable-indev=v4l --disable-indev=oss --enable-x11grab --enable-libpulse --disable-outdev=oss --enable-libfreetype --enable-pthreads --enable-libgsm --enable-libspeex --disable-amd3dnow --disable-amd3dnowext --disable-altivec --disable-avx --disable-mmx2 --disable-ssse3 --disable-vis --disable-neon --cpu=ho
libavutil 51. 35.100 / 51. 35.100
libavcodec 53. 61.100 / 53. 61.100
libavformat 53. 32.100 / 53. 32.100
libavdevice 53. 4.100 / 53. 4.100
libavfilter 2. 61.100 / 2. 61.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 6.100 / 0. 6.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, ape, from 'My Band 1971 CoolSounds.ape':
Metadata:
Album : CoolSounds
Title : C:\1\My Band 1971 CoolSounds
Comment : Exact Audio Copy
Duration: 00:59:15.47, start: 0.000000, bitrate: 829 kb/s
Stream #0:0: Audio: ape (APE / 0x20455041), 44100 Hz, stereo, s16
Output #0, mp3, to 'out.mp3':
Metadata:
TALB : CoolSounds
TIT2 : C:\1\My Band 1971 CoolSounds
Comment : Exact Audio Copy
TSSE : Lavf53.32.100
Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16, 192 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (ape -> libmp3lame)
Press [q] to stop, [?] for help
size= 83334kB time=00:59:15.55 bitrate= 192.0kbits/s
video:0kB audio:83333kB global headers:0kB muxing overhead 0.000892%
$

and, as you can see below, the resulting mp3 file is the same size as the mp3 file created using Konvertible (not surprising, since Konvertible is a GUI front-end for ffmpeg) and virtually the same as the mp3 file created by shntool.

$ file out.mp3
out.mp3: Audio file with ID3 version 2.4.0, contains: MPEG ADTS, layer III, v1, 192 kbps, 44.1 kHz, Stereo
$ ls -la out.mp3
-rw-r--r-- 1 fitzcarraldo users 85334024 Dec 20 18:14 out.mp3
$

So, there you have it: GUI or command line; take your pick!

Let’s hear it for Konqueror

My browser of choice on the desktop has been Firefox for many years. Firefox uses the Gecko rendering engine. As a backup Web browser I use Konqueror but configured to use WebKit, rather than KHTML, as the rendering engine. I’ve tried Chromium, Opera, Midori, rekonq, SeaMonkey and a bunch of others, but always found them lacking in some way in comparison to Firefox (I find Opera Mobile better than Firefox for Android on my mobile phone, though).

However, Firefox sometimes lets me down. For example, some months ago I wanted to book tickets online for a concert but Firefox would not display the seat map correctly, stopping me from being able to select seats. Konqueror saved the day. And, recently, Firefox no longer displays the video component of trailers on Rotten Tomatoes; only audio works. Firefox correctly plays videos from virtually all other sites I visit (YouTube, IMDb, iTunes Trailers, Vimeo, eTelegraph etc.) so why the sudden inability to display Rotten Tomatoes trailers? Today Firefox wouldn’t play a product video on an Amazon page either. So I launched Konqueror and it can play Rotten Tomatoes trailers and the Amazon video. What gives? They are both running on the same laptop in the same OS (Gentoo Linux) and desktop environment (KDE), using the same version of Flash, the same video driver etc. The only thing I can think of is that the Firefox rendering engine Gecko is the culprit. I assume WebKit in Konqueror is more capable than Gecko, although I don’t know enough to be certain that Gecko is the cause of the problem.

Anyway, if you want to configure Konqueror to use the WebKit rendering engine instead of the KHTML rendering engine, click on ‘Settings’ on the Konqueror menu bar, select ‘Configure Konqueror…’ and click on ‘General’. You’ll see ‘Default web browser engine’ in the right pane. Select WebKit and click ‘OK’. You’ll also need to have WebKit itself installed, of course. I have the packages qt-webkit (the WebKit module for the Qt toolkit) and kwebkitpart (a WebKit KPart for Konqueror) installed.

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