multiple binaries with same name in ubuntu/linux - linux

I have recently installed a webframework play (http://www.playframework.com/) and want to have the play executable in the system path ie $PATH. But ubuntu already defines a command called play. How do I overwrite the system defined command with my framework binary path so that command play on commandline calls my framework rather than the old application.
Installation: I downloaded zipped file of the framework and upzipped in one of my personal folder which contains the docs and the executable.

Never alter the contents of installed packages. Such changes can provoke hard to find problems in the system and anyway, they will most likely be overwritten again in subsequent updates. There are other alternatives:
obviously you can chose another name for your executable
place the executable in another part of your $PATH if its a "personal installation", typically ~/bin is used for such approach. Remember that the order of entries in the $PATH variable is important, first come first serve.
use the traditional /usr/local/bin location for locally added "wild" installations, this way there is some form of clean separation between clean packages and wild installed files inside the system
store your software in some other location and prepend that to your personal or system wide $PATH variable
store your executable under another name and create an alias (see man alias for an explanation) for it which allows to call it by some name that "hides" the original command this way. For this the executable can be addressed with an absolute path, so it dies not have to be found inside the $PATH variable.
In my personal opinion options 2. and 5. and the best if it comes to "personal installations".

If you are sure you'll never use the original play command, you could just remove the binary. But in general, this isn't a good idea, since some system component you don't think of might need it, and the next update will probably restore it.
The best thing to do is to prepend the directory of your play command to the PATH, for example, using PATH=/opt/framework/bin:$PATH in your .profile (assuming your play command installs to /opt/framework/bin/play), or the script that starts your web server, or wherever you need your play command.
Remember that does not make your play command global. A common mistake is to add the path in their .profile file, then call the program from crontab - crontab scripts will not execute .profile or .bashrc.

Related

Copying shell file to path

I'm new to WSL and Linux, but I'm trying to follow installation instructions for rhasspy (https://rhasspy.readthedocs.io/en/latest/installation/#windows-subsystem-for-linux-wsl). I have run the make install command successfully and the next step says I should copy rhasspy somewhere in my path but I can't quite figure out what copying to path means.
When installation is finished, copy rhasspy.sh somewhere in your PATH and rename it to rhasspy.
I added it to path but nothing changed so I was wondering if there is something I'm doing wrong. Right now when I run rhasspy on wsl it says rhasspy.sh: command not found. Any help would be really appreciated!
What it says is, put it in some place where the system will look for it when you type its name without full path in the shell.
There is an environment variable PATH that contains all those locations, separated by a :. (Check out echo $PATH.)
So, the author of these instructions leaves it up to you whether...
You want to copy the file to a location of your choice that is already in the PATH, such as /usr/local/bin or ~/bin.
Usually ~/bin is a good choice because it is per-user and doesn't pollute the system.
(Note that the directory ~/bin is added to the PATH by your .profile file only if it exists, so if you don't have this directory yet and create it now, you need to start a new login shell or run . ~/.profile1 before you can use it.)
- OR -
You want to create a new directory specifically for this application (say for example ~/opt/rhasspy) and append that directory to the PATH variable.
This can be done by adding the line export PATH=$PATH:~/opt/rhasspy to your ~/.profile file. Then, start a new login shell or reload the file using . ~/.profile1 for the changes to take effect.
If the directory in which this file is currently located is OK for you to keep permanently, then you can also just add that directory to the PATH instead of creating a new one.
Note: The PATH always contains directory paths in which the shell will look for executable files. It does not contain the actual file paths!
1: Yes, technically it is "cleaner" to log into a new shell or to run that one export statement manually instead of using . ~/.profile because the latter will apply things a second time that were already done before, so for example it can end up with the same directory in the PATH multiple times in the current session. In most cases that is fine though.
PATH is an environment variable. When you launch env, you see the list of known environment variables on your system.
In order to add something to your PATH variable, you need to take the variable, add the mentioned directory (preceeded by a semi-colon, most probably, as a separator) and store this again as the PATH variable. This can be done as follows (own example):
export PATH=$PATH:/home/this_user
the "PATH" it is referring to in linux is just inside the folder called /usr/bin. when you type a command into the terminal it looks for a program with that name inside the location. im not sure if this is the PATH you are looking for but hope it helps

Add software bin or just add soft link for executable file in bin when install software on linux?

I’m not root for the linux server,
so I choose to install softwares in my $HOME/local/bin, I already added the $HOME/local/bin directory to the PATH environment variable, wrote in my .bashrc.
Some softwares install this way like:
tar xvzf ncurses-5.9.tar.gz
cd ncurses-5.9
./configure --prefix=$HOME/local
make
make install
cd ..
So it will directly install in my $HOME/local/bin.
But for some softwares, after download like sbt-1.2.1.zip (based on java), and decompression, shows just a file fold sbt, it contains three foldsbin conf lib, and in its bin, contains one executable file named sbt and java9-rt-export.jar sbt-launch-lib.bash sbt-launch.jar sbt.bat.
Here I wonder:
I should just soft link this executable sbt file path under my $HOME/local/bin, then source my .bashrc?
Or, after decompression, add one line in my .bashrc export PATH="downloadpath/sbt/bin:$PATH"?
Since just one executable downloadpath/sbt/bin, so I'm not sure it is right to add whole bin fold path, if software's bin fold contains executable files (one or many), I think this situation is more convenient for just add it's bin in .bashrc, but even so, I'm not sure its right?
I'm not familiar with installation software, now I usually know way
but not why. Here I shows two ways (more ways not be showed here) to
install, executable file always be written in bin or src? But some
softwares no bin just src but no executable files in it...
Slurm also can use modules to install software, conda also other way, but I want to
confirm these traditional ways I mentioned (that two) still can be
used on slurm or conda?
However, any suggestion even one aspect's reminding will be grateful!
For precompiled software, or, in general, software that does not offer configure scripts or (C)make files, it is ofter better to leave them in their target directory and adapt the *PATH (PATH to binaries, but also LD_LIBRARY_PATH, LIBRARY_PATH to libraries and CPATH to include files and MANPATH to the man page) environment variables.
The reason is that the software might be configured to read files with hardcoded paths, relative to the position of the executable, such as libraries, etc.
In your case, you might also need to setup the CLASSPATH env variable to the directory with the jar files.
To ease software installation, you can use tools such as easybuild that can help, and even create user modules just like the system module installed by the system administrators.
There is something wrong in my opinion with your setup. If you don`t have root account on your server, is not better to test what you have to test, in a more safe environment - for example a vm/container on your developement machine ?
However, in your situation maybe it can be better to start sbt by using a separate bash script than modifying your .bashrc

What should Linux/Unix 'make install' consist of?

I've written a C++ program (command line, portable code) and I'm trying to release a Linux version at the same time as the Windows version. I've written a makefile as follows:
ayane: *.cpp *.h
g++ -Wno-write-strings -oayane *.cpp
Straightforward enough so far; but I'm given to understand it's customary to have a second step, make install. So when I put the install: target in the makefile... what command should be associated with it? (If possible I'd prefer it to work on all Unix systems as well as Linux.)
Installation
A less trivial installer will copy several things into place, first insuring that the appropriate paths exists (using mkdir -p or similar). Typically something like this:
the executable goes in $INSTALL_PATH/bin
any libraries built for external consumption go in $INSTALL_PATH/lib or $INSTALL_PATH/lib/yourappname
man pages go in $INSTALL_PATH/share/man/man1 and possibly other sections if appropriate
other docs go in $INSTALL_PATH/share/yourappname
default configuration files go in $INSTALL_PATH/etc/yourappname
headers for other to link against go in $INSTALL_PATH/include/yourappname
Installation path
The INSTALL_PATH is an input to the build system, and usually defaults to /usr/local. This gives your user the flexibility to install under their $HOME without needing elevated permission.
In the simplest case just use
INSTALL_PATH?=/usr/local
at the top of the makefile. Then the user can override it by setting an environment variable in their shell.
Deinstallation
You also occasionally see make installs that build a manifest to help with de-installation. The manifest can even be written as a script to do the work.
Another approach is just to have a make uninstall that looks for the things make install places, and removes them if they exist.
In the simplest case you just copy the newly created executable into the /usr/local/bin path. Of course, it's usually more complicated than that.
Notice that most of these operations require special rights, which is why make install is usually invoked using sudo.
make install is usually the step that "installs" the binary into the correct place.
For example, when compiling Vim, make install may place it in /usr/local/bin
Not all Makefiles have a make install

Choosing between multiple executables with same name in Linux

The system I am using has gnuplot installed in /usr/bin. I don't have root, but I needed a newer version of gnuplot, so I installed it to $HOME/usr/bin.
I added $HOME/usr/bin to my path, but it still executes the one in /usr/bin if I just use the gnuplot command. I'd rather not have to specify $HOME/usr/bin/gnuplot every time I have to use it.
How do I tell Linux to use the one in my home directory, and not the one in /usr/bin?
Executables are found in PATH order. You need to prepend ${HOME}/usr/bin to your path, like so:
export PATH="${HOME}/usr/bin:$PATH"
Executables are found in PATH order. Your PATH apparently is set up such that /usr/bin precedes ~/usr/bin/.
Besides modifying the PATH as has been explained, you can also use aliases like this (in BASH)
alias gn=$HOME/usr/bin/gnuplot
then you just run it with
gn
What Bombe says is ok. I would add that you should declare your user specific PATH entries inside your user's bashrc ($HOME/.bashrc), so your PATH settings only apply to your user.

Where to put helper-scripts with GNU autoconf/automake?

I'm working on a project that will be distributed with GNU autoconf/automake, and I have a set of bash scripts which call awk scripts. I would like the bash scripts to end up in the $PATH, but not the awk scripts. How should I insert these into the project? Should they be put in with other binaries?
Also, is there a way to determine the final location of the file after installation? I presume that /usr/local/bin isn't always where the executables end up...
You can just list the scripts that you want to be installed in Makefile.am:
bin_SCRIPTS = foo bar
This will cause foo and bar to be installed during make install. To get the path to their final location, you can use #bindir# in foo.in and let configure build foo for you. For example, in configure.ac:
AC_CONFIG_FILES([foo bar])
and then in foo.in:
#!/bin/sh
prefix=#prefix#
exec_prefix=#exec_prefix#
bindir=#bindir#
echo bindir = $bindir
Keep in mind that the person running configure may specify any of --prefix, --exec_prefix, or
--bindir, and the installation may be redirected with a DESTDIR. Using the technique described here, DESTDIR will not be taken into account and the script will be installed in a location other than the path that it will echo. This is by design, and is the correct behavior, as usually a DESTDIR installation is used to create a tarball that will eventually be unpacked into the filesystem in such a way that the bindir in the script becomes valid.
Add something like this to Makefile.am
scriptsdir = $(prefix)/bin
scripts_DATA = awkscript1 awkscript2
In this case it will install awkscript in $(prefix)/bin (you can also use $(bindir)).
Note: Dont forget that the first should be named name + dir (scripts -> scriptsdir) and the second should be name + _DATA (scripts -> scripts_DATA).
Jonathan, in response to your additional question: if you want to replace the value of prefix at the time of build, you will need to:
rename your script 'myscript' to 'myscript.in'
add a rule to configure.ac to generate it at the bottom
use a macro I made called AS_AC_EXPAND
use it like this:
AS_AC_EXPAND(BINDIR, $bindir)
in your 'myscript.in', you can now use #BINDIR# and it will get expanded to the full path where the script will end up being installed.
Note that you shouldn't use PREFIX directly, any of the installation directories can potentially be changed so you really want to use the value passed to configure for bindir and expand that.
If the awk scripts won't go into the main bin directory (prefix/bin), then you need to place them in an appropriate sub-directory - probably of lib but possibly libexec or share (since the awk scripts are probably platform neutral).
Correct: software won't necessarily end up in /usr/local/bin; on my machine, /usr/local/bin is managed by MIS and all the software I install therefore goes under /usr/gnu/. I use: ./configure --prefix=/usr/gnu to get the software installed where I want it.
You can embed the value of PREFIX in the bash scripts -- effectively, you will 'compile' the scripts to include the install location. Be aware of problems during the build testing - you may need to locate the scripts relative to the current directory first and relative to PREFIX later.

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