gcc 4.4.4 c89 Fedora 13
I am wondering what is better. To give you a compile of examples: apache runtime portable and log4c.
The apr version in my fedora repository is 1.3.9. The latest stable version on the apr website is 1.4.2.
Questions
Would it be better to download from the website and install, or install using yum?
When you install from yum sometimes it can put things in many directories. When installing from the tarball you can put the includes and libraries where you want.
The log4c the versions are the same, as this is an old project.
I downloaded log4c using yum. I copied all the includes and libraries to my development project directory.
i.e.
project_name/tools/log4c/inc
project_name/tools/log4c/libs
However, I noticed that I had to look for some headers in the /usr/include directory.
Many thanks for any suggestions,
If the version in your distribution's package repository is recent enough, just use that.
Advantages are automatic updates via your distribution, easy and fast installs (including the automatic fetching and installing of dependencies!) and easy removals of packages.
If you install stuff from .tar.gz by yourself, you have to play your own distribution - keep track of security issues and bugs.
Using distribution packages, you have an eye on security problems as well, but a lot work does the distributor for you (like developing patches, repackaging, testing and catching serious stuff). Of course each distributor has a policy how to deal with different classes of issues for different package repositories. But with your own .tar.gz installs you have nothing of this.
It's an age-old question I think. And it's the same on all Linux distributions.
The package is created by someone - that person has an opinion as to where stuff should go. You may not agree - but by using a package you are spared chasing down all the dependencies needed to compile and install the software.
So for full control: roll your own - but be prepared for the possible work
otherwise use the package.
My view:
Use packages until it's impossible to do so (conflicts, compile parameters needed, ..) . I'd much rather spend time getting the software to work for me, than spend time compiling.
I usually use the packages provided by my distribution, if they are of a new enough version. There is two reasons for that:
1) Someone will make sure that I get new packages if security vulnerabilities in the old ones are uncovered.
2) It saves me time.
When I set up a development project, I never create my own include/lib directories unless the project itself is the authorative source for the relevant files I put there.
I use pkg-config to provide the location of necessary libraries and include files to my compiler. pkg-config use some .pc-files as a source of information about where things are supposed to be, and these are maintained by the same people who create the packages for your distribution. Some libraries does not provide this file, but an alternative '-config'-script. I'll provide two examples:
I'm not running Fedora 13, but an example on Ubuntu 10.04 would be;
*) Install liblog4c-dev
*) The command "log4c-config --libs" returns "-L/usr/lib -llog4c" ...
*) The command "log4c-config --cflags" returns "-I/usr/include"
And for an example using pkg-config (I'll use SDL for the example):
*) Install libsdl1.2-dev
*) The command "pkg-config sdl --libs" returns "-lSDL"
*) The command "pkg-config sdl --cflags" returns "-D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL"
... So even if another distribution decides to put things in different paths, there are scripts that are supposed to give you a reliable answer to where things is - so things can be built on most distributions. Autotools (automake, autoconf, and the likes) amd cmake are quite helpful to make sure that you don't have to deal with these problems.
If you want to build something that has to work with the Apache that's included with Fedora, then it's probably best to use the apr version in Fedora. That way you get automatic security updates etc. If you want to develop something new yourself, it might be useful to track upstream instead.
Also, normally the headers that your distro provides should be found by gcc & co. without you needing to copy them, so it doesn't matter where they are stored by yum/rpm.
Related
I'm new to c development, but I have some experience in other modern languages .so the first thing that I found hard is dependencies and deployment, while we got Gradle, maven, NuGet and pipy and... but in c I find it a bit difficult to manage this process.
for example, I have an app that should use mongo-c-library, log4c,libarchive so basically, in my development environment, I download and unzip all of the tar files of the above libraries and then followed their instruction(usually some make stuff) and installed them in order to include them in code make the code work.
I have studied a bit about CMake but I couldn't get a clear picture of how that could actually solve the problem.
at this moment my best solution is to create an install bash script and zip all dependencies unzipped folder with that install script and then send it to the production server to deploy it.
1.The first question is : is it possible to just copy and past all of .so .h and etc files in /path/of/installed/dependencies/include
and /path/of/installed/dependencies/lib in the destination server libary path.
2.if not what is the faster way?
while I was surfing the CMake source file I found that its developers just use this package source code directly.
cmxxx contains the xxx sources and headers files.
3.how can apt-get and Linux package manager help in the deployment process?
2 first question was more about dependencies. imagine we have a simple c app and we want to install(build and make a useable executable file) quickly. how it can be related to .deb packages.
1.The first question is : is it possible to just copy and past all of .so .h and etc files in /path/of/installed/dependencies/include and /path/of/installed/dependencies/lib in the destination server libary path.
Yes, technically it's possible. That's essentially what package managers do under the hood. However, doing that is a colossal mistake and screams bad practices. If that's what you want then in the very least you should look into package managers to build up your own installer, which handles this sort of stuff already for you.
2.if not what is the faster way?
You're actually asking an entirely different question, which is: how should I distribute my code, and how do I expect users to use/deploy it?
If you want users to access your source code and build it locally, as you've mentioned cmake then you just to set up your project right as cmake already supports that usecase.
If instead you just want to distribute binaries for a platform then you'll need to build and package that code. Again, cmake can also help you on that one, as cmake's cpack supports generating some types of packages like DEB packages used by Debian and Ubuntu, and which are handled by apt.
3.how can apt-get and Linux package manager help in the deployment process?
apt is designed to download and install packages from a repository.
Under the hood, apt uses DEB packages, which can be installed with dpkg.
If you're targeting a system that uses apt/deb, you can build DEB packages whenever you release a version to allow people to install their software.
You can also go a step beyond and release your DEB packages in a Personal Package Archive.
You would typically NOT download and install source packages. Instead you should generally rely on the libraries and development packages of the distribution. When building your own package you would typically just reference the packages or files that your package is dependent on. Then you build your own package and you're done. Upon installation of your package, all dependencies will automatically be resolved in an appropriate order.
What exactly needs to be done is dependent on the package management system, but generally the above statements apply. Be advised, package management apparently is pretty hard, because so many 3rd party developers screw it up.
I have just started a university course in C and we have been instructed to run a makefile through Cygwin (which uses the GCC compiler), however I have very little knowledge about computers and am out of ideas as to how to solve this. When I run the makefile it says:
cannot find -lncurses.
I understand ncurses is a library and the compiler is looking for it as some of the files in the makefile need it, but I don't understand how it is missing, where it is, or how I point the compiler to it. Can anyone offer me any advice?
You need aditional packages.
From https://cygwin.com/ml/cygwin-announce/2001/msg00124.html
The ncurses package has been updated to ncurses-5.2-7. ncurses is a
package that provides character and terminal handling libraries,
including 'gui-like' panels and menus. It is often used instead of
termcap.
MAJOR CHANGES to the ncurses package:
The ncurses package has been split into three separate packages:
ncurses-5.2-7 (contains the static libs, header files,
man pages, etc)
libncurses6-5.2-2 (contains the new DLL's)
terminfo-5.2-1 (contains the terminfo database)
libncurses5-5.2-1 is a new package containing the old
DLLs from ncurses-5.2-5, for backward compatibility.
ncurses is now built using the 'auto-import' features of
recent binutils.
ncurses-5.2-5a if it's necessary to rollback, this package
contains the files from ncurses-5.2-5
(post splitup) Thus, this package +
terminfo + libncurses5 = old ncurses-5.2-5.
See NOTES below for additional information.
INSTALLATION:
To update your installation, click on the "Install Cygwin now" link on
the http://cygwin.com/ web page. This downloads setup.exe to your
system. Then, run setup TWICE and answer all of the questions EACH
TIME. The FIRST time, update ONLY the ncurses package. The SECOND
time, install the terminfo, libncurses5, and libncurses6 packages.
You MUST do BOTH steps.
I want to run an application based on Qt5 shared objects.
Although I have apt installed qt5-default, qttools5-dev and qttools5-dev-tools I get the error bellow:
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5: version `Qt_5.7' not found
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5: version `Qt_5' not found
/usr/lib/x86_64-linux-gnu/libQt5Gui.so.5: version `Qt_5' not found
/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5: version `Qt_5' not found
I have also tried to change some environment variables as LD_LIBRARY_PATH and DYLD_LIBRARY_PATH, resulted in no success!
What do you suggest?
When you built your application, which version of Qt5 did you build against? You can see this in QtCreator by looking at the currently selected kit:
If you just installed QtCreator from binary, it is shipped with it's own set of Qt5 shared libraries that your application is linked against, however your OS' version of those libraries (those installed from apt-get and similar) may not match.
When you try to run the application on it's own outside QtCreator, it may try to link against the OS version of the libs which are usually much older.
There are many ways to resolve this. One way, which would be preferred if you don't care for the newest version of Qt, is simply building towards the Qt libs supploed by the OS. You can do this by creating a new kit that specifies to build against the OS' libraries following this procedure.
Another way is shipping the shared libraries that you used from QtCreator together with the application so that those will override the OS ones. Usually just chucking them into the same folder as the executable will do the trick, as they will be found before the ones under /usr/lib/whatever etc.
Yet another way is to build your own static version of Qt and link with that. This has some benefits and some drawbacks. This is an advanced topic, so I won't go into detail (you can see here). But in this case the Qt libs are built into your app and will not depend on any external Qt libs version.
I am new to fedora (Linux). Just installed glib packages using yum install glib*. But still not able to compile.
I used locate to find where the pkg-config file is. I opened all of these but could not find PKG_CONFIG_PATH environment variable. Any help? :)
pkg-config files are stored in /usr/lib64/pkgconfig/* or /usr/lib/pkgconfig/* (depending on whether you're on 64-bit or 32-bit).
The glib package contains glib 1.x, for glib 2.x the right package is glib2 (backwards-incompatible API changes require a new package).
Furthermore, development headers, documentation, pkg-config files, etc., are provided in a separate package, which is usually called '$packagename-devel'. This split allows you avoid installing all the development stuff if all you want to do is use the library. So, what you really want is yum install glib2-devel.
Note that, since you know the pkg-config name, you can just do yum provides '*/glib-2.0.pc' (or provide the full path and you'll only get a single result) to find the packages which provide the glib-2.0 pkg-config file. With dnf you can also just do something like dnf install '/usr/lib64/pkgconfig/glib-2.0.pc', not sure if the version of yum from F16 can do the same or not, which brings me to…
Fedora 16 is way too old. Unless you have a very good reason for using this specific version of Fedora, stop doing so. Beyond being a much less pleasant experience, Fedora 16 is old enough that it is no longer receiving security updates. If you need to use something from that era you should find something that is still supported (RHEL 6 is based of F12, RHEL 7 is based on F19, you can use CentOS if you don't want to pay for support).
I am trying to get memcached running on Windows. I have downloaded memcached stable latest and compiled it using Mingw under Windows 7. Configure failed with error,
checking for libevent directory... configure: error: libevent is
required. You can get it from http://www.monkey.org/~provos/libevent/
If it's already installed, specify its path using --with-libevent=/dir/
Then I downloaded libevent and compiled it. This produced 3 DLLs, libeventcore, libevent-extra and libevent-2.0.5.
I ran configure on memcached again with the option --with-libevent. But for some reason, it fails again with the same error. I have no clue on why it is failing. Can anyone help me to resolve this issue? Or is there a better way to get memcached running on Windows? I have seen lot of pre-built binaries for Windows. But all of them uses old versions of memcached. And AFAIK, Windows is officially supported by memcached in the newer versions.
I am using Windows7 64bit version with MinGW.
After you run make in libevent dir you get the files ready, but to make full use of it, they must be installed. So make install step is needed. If you configured it with a prefix, it will land in the directory of your choice. Otherwise it is /usr/local.
So maybe it's enough to run make install in libevent dir and run configure from memcache without parameters.
If you still have problems passing the configure stage, look at config.log. It shows the source file and the gcc command on which it failed.
Unfortunately successful configure is not everything. Later it fails on inclusion of sys/socket.h, netinet/in.h and netdb.h and perhaps also -pthread gcc parameter. I'm afraid it won't compile on mingw. At least not without a serious porting effort.
As I know, Never had an official Memcached port for Windows (Yes, there were few individual efforts. Last knowing porting effort can find on version 1.2.6 here) Best known Implementation for Memcached for windows on Couchbase with Memcached Bucket.
Late to the party I realize but the answer is to use:
$ export LIBS=-lws2_32
which will place $LIBS at the end of compile calls so that it is linked to libws2_32.a or winsocks2, but this probably means that your did not configure your build correctly and you will subsequent errors such as #include <sys/socket.h> header not found, etc.
see mingw-linker-error-winsock