Making gfortran version 11 as default - linux

My code runs fine with the command
gfortran-11 Hello.f90 -o Hello
but if I check the version of the gfortran, it shows 9.3.0 on Ubuntu 20.04.
So my concern is how to make it default or do I have to type gfortran-11 every time I use it?

One way to solve this is to create a symlink to gfortran-11 called gfortran, and to add this symlink to your PATH with higher priority than the original gfortran.
This could be acheived by e.g. running
mkdir ~/.bin
ln -s [path_to_gfortran-11] ~/.bin/gfortran
and then adding
export PATH=~/.bin:$PATH
to your .bashrc or equivalent.

This is really a system administration question. Since it tangentially deals with a compiler, it might be on-topic.
There are various ways how concurrent versions are treated in various operating systems. If you use Linux, you can use
alias gfortran=gfortran-11
You can put this into your ~/.bashrc or some equivalent, if you use one (e.g., the ~/.bash_aliases file - see https://askubuntu.com/questions/1414/how-to-create-a-permanent-alias).
For tools like Make you can normally set
export FC=gfortran-11
or
FC=gfortran-11 ./make
or some other variable name that your Makefile happens to use. I use this routinely with SCons.
Another good option is the update-alternatives system. See https://askubuntu.com/questions/26498/how-to-choose-the-default-gcc-and-g-version
If you configure (install) the appropriate options according to the instructions (change g++ to gfortran), you will be able to switch between the versions using
sudo update-alternatives --config gfortran

Related

How do you get a launcher for firefox?

I hope that I'm tagging/asking on the correct page. I'm Using Linux Mint 6.0, but it could be OS independent.
So the used command for installing Firefox was
nix-env -iA nixpkgs.firefox-esr
When I type which firefox, I get:
/home/foo/.nix-profile/bin/firefox
So Linux Mint comes with Chrome preinstalled, which has a launcher, e.g. also in the start menu. How do I get that for firefox as well? I didn't find a tool to create such a launcher in Mint and I actually think, that nix should do that for me.
EDIT: I also found this page which seemed helpful and advertised e.g. the KDE Kickoff, but I wasn't able to get that one to run.
I can only speak for Ubuntu launchers, but other distros will have launcher files that will have a similar setup
TLDR, add ~/.nix-profile/share to XDG_DATA_DIRS env variable on login. Add the following to ~/.profile after nix loading commands
export XDG_DATA_DIRS=$HOME/.nix-profile/share:$XDG_DATA_DIRS
Explanation:
Installed packages via nix will have an immutable path in nix/store. ~/.nix-profile/bin/firefox is the derivation your current nix environment is linked to (if you update the firefox package, it'll point to the new one)
This means you can create a launcher file for that executable. Lets see if the firefox-esr derivation comes with a desktop launcher or not:
$ nix-build '<nixpkgs>' -A firefox-esr
This will build the package and give you a derivation path. For my current channel it is /nix/store/3iipcmiykgr4p34fg3rkicdz1bw584gm-firefox-102.2.0esr
If I check inside it, there is a .desktop file which defines Ubuntu launchers:
$ ls /nix/store/3iipcmiykgr4p34fg3rkicdz1bw584gm-firefox-102.2.0esr/share/applications
firefox.desktop
These files will also be available under ~/.nix-profile/share/applications so you can simply add that to XDG_DATA_DIRS env variable before boot
If an application did not have one, you can manually make one and add it under ~/.local/share/applications, then set the executable path to the nix one
So SuperSandro2000 explained in the comments, that firefox from nix ships with a .desktop file already. This can be easily added to the start menu and lies in
/nix/store/...-firefox-XXX.X/share/applications/firefox.desktop
If there is no such file included, the most direct way could be (imho) to just create a simple bash script:
#!/bin/bash
./home/foo/.nix-profile/bin/firefox & #Run Firefox
echo Firefox was started with PID $!
In order to make it runnable, enter chmod +x your_skript_name.sh. Afterwards, ./firefox 2> /dev/null & can be used instead to run it silently in the background.
You can also consider the developer/command line options for firefox (Archive) or this blog article here.
Maybe /usr/bin/menulibre is also the right application, it allows you to create .desktop files. This app can also be found by right-clicking on the start "menu".

How to specify which version of perl to use for a script without installing perlbrew

I have a script that must be run in Perl 5.10.1, although my university's linux cluster system uses the most recent version of Perl. I tried to install Perlbrew, but I don't think it worked.
I'm not sure how to specify the perl version in the shebang because of how I call/run this script. There is "cluster.pl", which is run by running "./command.txt".
Also, I don't think I can install Perlbrew because it's the university's linux system: After copy-pasting the installation commands, my terminal screen said the perlbrew patch was installed, but when I used "perlbrew install perl-5.10.1", it would say "command perlbrew not found" I don't know how to run the script
As of now, cluster.pl has this shebang:
#!/usr/bin/perl
One related question said to write this in the command line
/program/perl_v5.6.1/bin/perl scriptName.pl
#OP needed to use version 5.6.1, unlike me (I need 5.10.1)
However, I don't know whether "program" is OP's directory or a mandatory part of the path
Below is command.txt, which has the necessary input arguments:
#this is command.txt
./cluster.pl Datachr1 2 galGal5.Chroinfo.txt
Essentially, where would the suggested shebang go? Would I include "program" in my path too?
If you wrap your script in Perl's packaging framework, this is handled for you automatically. When it installs scripts, it changes the shebang line with the actual perl. You end up with something like this at the top of the file:
#!/usr/local/perls/perl-5.30.0/bin/perl
eval 'exec /usr/local/perls/perl-5.30.0/bin/perl -S $0 ${1+"$#"}'
if $running_under_some_shell;
#!/usr/local/bin/perl
You might try this with my app-rhich distribution. Download the tarball and run the Makefile.PL with the perl you want. Run make and it builds stuff into the blib staging directory. You should see the modified shebang there:
$ /Users/brian/bin/perls/perl5.30.0 MAkefile.PL
Checking if your kit is complete...
Looks good
WARNING: Older versions of ExtUtils::MakeMaker may errantly install README.pod as part of this distribution. It is recommended to avoid using this path in CPAN modules.
Generating a Unix-style Makefile
Writing Makefile for App::rhich
Writing MYMETA.yml and MYMETA.json
$ make build
make: *** No rule to make target `build'. Stop.
$ make
cp lib/App/rhich.pm blib/lib/App/rhich.pm
cp script/rhich blib/script/rhich
"/usr/local/perls/perl-5.30.0/bin/perl" -MExtUtils::MY -e 'MY->fixin(shift)' -- blib/script/rhich
Manifying 1 pod document
Manifying 1 pod document
brian#otter app-rhich (master)[3125]
$ more blib/script/
#!/usr/local/perls/perl-5.30.0/bin/perl
package rhich;
use strict;
use warnings;
However, if your path to perl is a symlink to some other perl, this can get confused. I don't use perlbrew because I don't think it adds much other than saving you looking up a download URL. I install multiple perls (and How should I install more than one version of Perl?) and can use paths to them so I know which version using. There's a similar problem with env depending on how you set up your path. How you handle that is based on how you decide to manage things, but it's these sorts of questions that show that the tools of convenience aren't really that convenient.

Subversion CLI default text editor on Linux

While there is no shortage of information on how to set a text editor for the Subversion Command Line Interface to use (see here, here, and here for example), I can't figure out where my local system is getting the text editor information from.
On my system, when I perform an svn commit, it opens vim for a commit message. Since this is what I want, I never really thought about it. This has always just worked. However, recently a co-worker was trying to commit, and it failed with an error saying the editor was not set. I never went out of my way to set an editor, so I am very confused about this.
I am running Ubuntu 12.04 and I have compiled and installed the Subversion CLI client version 1.8.10 from source code. Previous to that, I was using whatever Ubuntu's Canonical system installed with apt-get install subversion.
The Using External Editors section of the Subversion Book states the following possibilities for setting the text editor:
--editor-cmd command-line option
SVN_EDITOR environment variable
editor-cmd runtime configuration option
VISUAL environment variable
EDITOR environment variable
Possibly, a fallback value built into the Subversion libraries (not present in the official builds)
I have investigated these places and have not found how the default text editor is set on my computer:
Not using --editor-cmd option when committing
SVN_EDITOR environment variable not set
editor-cmd is not set in either my ~/.subversion/config, nor in /etc/subversion/config. Both of these files exist, but the line is commented out.
VISUAL environment variable not set
EDITOR environment variable not set
I'm downloading the official repository, so there should be no fallback.
There must be another place where the default can be set. Does anybody know?
Edit: There was a suggestion that Subversion might be calling /usr/bin/editor, and this is not set up on my co-worker's machine. I discovered that /usr/bin/editor is set up the same on both my system and my co-worker's system.
When you download the source directly (and build it - assuming you have the build dependencies met) you specify (or you can omit it) the default fallback editor. Normally source builds are done with something like this on Ubuntu (assume I have extracted/downloaded the subversion 1.8.10 source from here):
./configure
make
sudo make install
Notice the ./configure command above doesn't specify any options. The defaults will install to the prefix /usr/local . Prior to issuing those commands (on Ubuntu 12.04) I ran sudo apt-get build-dep subversion . I then did the commands above to build and install. I made sure that options 1-5 (In the OPs question) were not satisfied and then tried to commit a change to a repository. I got this as a response:
svn: E205007: Commit failed (details follow):
svn: E205007: Could not use external editor to fetch log message; consider setting the $SVN_EDITOR environment variable or using the --message (-m) or --file (-F) options
svn: E205007: None of the environment variables SVN_EDITOR, VISUAL or EDITOR are set, and no 'editor-cmd' run-time configuration option was found
Since I didn't remove the official Ubuntu subversion I had to run mine as /usr/local/bin/svn to make sure I was using the one I built. I could have used sudo apt-get remove subversion to remove the official one as well just to make sure.
Now if one runs these commands to rebuild the source:
make clean
./configure --with-editor=/usr/bin/editor
make
sudo make install
One should find that if options 1 to 5 are not satisfied and this version of subversion is run it should default to running whatever /usr/bin/editor points to. On Ubuntu that will depend on what alternative is being used.
So when Ubuntu does an official build where does their fallback editor come from? I went to the 12.04 source repository for subversion at this link . On the right hand side I downloaded the diff file subversion_1.6.17dfsg-3ubuntu3.4.diff.gz . I opened up the diff file Ubuntu uses and scrolling down you can find they use this set of ./configure options (flags):
confflags := \
--prefix=/usr \
--libdir=$(libdir) \
--mandir=\$${prefix}/share/man \
--with-apr=/usr \
--with-apr-util=/usr \
--with-neon=/usr \
--with-serf=/usr \
--with-berkeley-db=:::db \
--with-sasl=/usr \
--with-editor=/usr/bin/editor \
--with-ruby-sitedir=/usr/lib/ruby \
--with-swig=/usr \
--with-kwallet \
--with-gnome-keyring
The bold entry shows that they use /usr/bin/editor as their fallback.
I have built subversion 1.8.10 from source on Ubuntu 12.04 and got the expected behavior. This suggests one of these possibilities:
On one of the systems the options 1 through 5 is actually met.
One version of subversion was built with the --with-editor configure flag (either directly or indirectly). The fallback would point to whatever the --with-editor configure flag was set to.
On one of the systems the wrong version of subversion is being run. One possibility is that the official subversion on Ubuntu is in fact being used. If that is the case it was built to use /usr/bin/editor as a fallback.
On one of your systems you have an alias (or equivalent) for svn that specifies an editor. Aliases would be specified in a startup script like ~/.bashrc, ~/.bash_profile, /etc/bash.bashrc for example.
I think the normal way to specify this on Linux and other Unix-like systems, is to set the VISUAL environment variable (for GUI editors) or the EDITOR variable (for editors running in a terminal).
Try this:
update-alternatives --display editor
Run strings on your svn binary to see if it mentions Vim or any related env vars inside.
Also committing under strace -f may reveal something.
Set this in your .bashrc file.
Don't forget to "source .bashrc" or reopen terminal.
export SVN_EDITOR='vim'

Compiler options basic ./configure explanation

recently, i try to compile a gnu wget from source code in cygwin environtment that pop-up error if perl is not found. otherwise, perl is installed both perl and perl5 on /bin/ but the wget is try search perl on /usr/bin. i think i have missed basic ./configure to setup path executable. so my question is basic.
what is it all about options on below:
*
--bindir=DIR
--sbindir=DIR
--libexecdir=DIR
*
Thank you
These options specify directories where a software package being compiled is going to be installed. As far as I remember it doesn't deal with checks performed by configure. Make sure that perl is in $PATH. If nothing helps, try to locate the exact place in the configure script (usually it's robot-generated and not intended for human eyes, but afterall it's a shell script, and anybody can read it) and see what checks exactly are performed to locate perl.
Update: I have checked, the tests corresponding to perl look like this in configure.ac (which essentially is a "source code" for configure):
AC_PATH_PROGS(PERL, [perl5 perl], no)
AC_PATH_PROG(POD2MAN, pod2man, no)
This means that PERL with executable named perl5 or perl (somewhere in $PATH) is checked, and then POD2MAN with executable pod2man. Carefully check the configure output and config.log file and see what tests have failed.
Update2: The third argument of the AC_PATH_PROG and AC_PATH_PROGS is value-if-no-found. Also you may specify the fourth argument, $PATH for this particular check. Make sure that configure gets rebuilt after you changed configure.ac (usually it happens automatically, but may be performed by autoconf explicitly)
what is it all about options on below:
*
--bindir=DIR
--sbindir=DIR
--libexecdir=DIR
The first (bindir), is where binaries will be installed. For wget, that's (on my system) /usr/bin.
The second (sbindir), is where static binaries will be installed. You might set that to /usr/sbin.
The third (libexecdir), is where your runtime libraries are to be installed. That's usually /usr/lib.
In fact, usually you let configure set all three by using --prefix.
./configure --prefix=/usr/local

Cannot run Code::Blocks: libwx_gtk2u-2.8.so.0 not found

I am trying to install Code::Blocks 10.05 from (non-SVN) sources (codeblocks-10.05-src.tar.bz2). My OS is Ubuntu 11.04. I needed to download and install wxWidgets first (I now have wxGTK-2.8.12), which seemed to work. I compiled it according to these instructions:
http://wiki.codeblocks.org/index.php?title=Installing_Code::Blocks_from_source_on_Linux
Then I configured C::B with
./configure --with-wx-config=/opt/wx/2.8/bin/wx-config
and ran
export LDFLAGS="-Wl,-R /opt/wx/2.8/lib"
make
sudo -i
make install
When trying to run C::B, I get the following error:
codeblocks: error while loading shared libraries: libwx_gtk2u-2.8.so.0: cannot open shared object file: No such file or directory
The same question was asked here: error while loading shared libraries, but the suggested solution (namely adding the wxWidgets config to the options passed to configure) didn't work for me.
The output of wx-config --prefix is /opt/wx/2.8,
The output of wx-config --libs is -L/opt/wx/2.8/lib -pthread -lwx_gtk2u-2.8,
and that of which wx-config is /opt/wx/2.8/bin/wx-config.
I looked for the library and found /opt/wx/lib/libwx_gtk2u-2.8.so.0 to be a link to libwx_gtk2u-2.8.so.0.8.0 in the same folder.
What might be wrong here?
The problem is that the program cannot find the WX widgets libraries at run time. You will need to set your LD_LIBRARY_PATH variable to include the location of wxWidgets like this:
LD_LIBRARY_PATH=/opt/wx/2.8/lib ./codeblocks
The reason why its failing is because you compiled codeblocks against wxWidgets found in /opt/ and not the one installed in /usr/; the program doesn't know to look in /opt for the wx libraries.
Probably the easiest way to get code::blocks up and running on Ubuntu is to just install it via the Synaptic Package Manager. Just type in codeblocks into 'Quick search'. Find codeblocks on the list and just right-click to mark for install. Any dependencies and missing libraries needed will automatically be handled and installed by Synaptic as necessary.
If you're interested in trying the C::B nightly builds on Ubuntu then you'll want to checkout Jens' unofficial debian-repository here.
You can visit Why do I have to define LD_LIBRARY_PATH with an export every time I run my application? for a more generic case. For a particular case like yours you can follow the below given steps
If you had installed wxGTK then you would see the file in /usr/local/lib. You would get this error when the the above path is not as part of the makefile. I received this error while starting wxFormBuilder after building from source on CentOS. There are 2 approaches.
Approach 1: Putting the path in .bashrc
gedit /home/{your-username}/.bashrc
Then after the line # User specific aliases and functions paste the following
export $LD_LIBRARY_PATH=/usr/local/lib.
This would work for fine but for the current login, but for other users like root you might have to do the same in the respective .bashrc files.
Approach 2: Creating your own conf files
cd /etc/ld.so.conf.d
gedit wxformbuilder.conf
Give the path /usr/local/lib and save the file.
ldconfig (To update the library path).

Resources