I Want to know , What is the purpose of packages "provide" and "if-needed" commands in TCL ? Please any body clarify my doubts.
Thanks in Advance.
The package provide command goes in the definition code of a package to declare that a particular package with a particular version has been defined.
Here's a trivial example:
namespace eval ::foo {
proc bar {} {
puts "this is the bar procedure in the foo namespace"
}
}
package provide foobar 1.1
The aim is that a package is a higher-level concept than just “oh, here's a bunch of files that you source”, even though that's quite possibly how it is implemented.
Some people prefer to put the package provide at the top of the script.
The package ifneeded command is used to supply metadata about a package to Tcl before loading the package itself. It goes inside a script named pkgIndex.tcl (usually) in the same directory as your package implementation, and it is used to say “if you want to use the package with this name and this version, run this script”. The final bit you need to know about this is that the package discovery code (run when you ask for a package it doesn't know about) runs the pkgIndex.tcl scripts that it finds in contexts that define the variable dir to be the directory containing the pkgIndex.tcl script that is being run; you don't need to do anything special to relocate the package if you use that convention (which is really convenient).
An example that might match up with the above code:
package ifneeded foobar 1.1 [list source [file join $dir foobar.tcl]]
There is a library command to generate the pkgIndex.tcl scripts for you — pkg_mkIndex — but I don't use it as it's not exactly difficult to write it by hand. (Note also that just because we've implemented the package with just a single Tcl script this time doesn't mean that it has to be done that way. It could also be many scripts, or shared libraries, or a mix of scripts and shared libraries. The user of the package shouldn't have to care about this.)
Maybe you just need an example to see how these commands are working.
Building reusable libraries is a good topic in the tcl tutorial which explaines how package ifneeded, provide and require fit in.
https://www.tcl.tk/man/tcl8.5/tutorial/Tcl31.html
Related
I want to make a tcl package , and I am writing In tcl and also in itcl.
Now ,
My first problem is that I have couple of sources files that are included one in the other , so I am adding the command source that should do the include between them. If I create a package with the command package provide is this will still work?
My second problem is that I don't really know how to create this package.
I added to my upper module script the command package provide pack 1.0, but I understood that auto_path should be also updated and mk_index file should with sources in it.
I searched on the internet and couldn't find good example for it.
By the way , I created all my classes and procedures under the global namespace in my sources files , is it ok? or should I wrap them inside a new namespace?
So I searched a little bit more about it and found those two absolutely wonderfull websites:
https://www.tcl.tk/man/tcl8.5/tutorial/Tcl31.html
http://www.wjduquette.com/tcl/namespaces.html
it is explained there very good.
MSI database contains set of tables, and I can successfully enumerate File table, which has all deployable file' meta-deta. What I need to extract is the actual contents of those files. msiexec, lessmsi, 7-zip all can do it, but I couldn't find any source/API to do it.
What I've discovered it that all other (resource) files are in Binary table, and Data field can be used to get content of those files (like icons, custom DLL etc).
Further, I found and know that Media table contains information about the .CAB file (MSI has all content embedded with <MediaTemplate EmbedCab="yes"/>. This simply means the CAB file contains the actual content. I probably need to read contents from "Structured Storage" of the .msi file.
How to extract the contents of CAB/MSI file, using native C Msi* functions?
Phil has given you the easy/simple answer but I thought I might give you a little more information since you've done some research. Checkout:
https://msdn.microsoft.com/en-us/library/windows/desktop/aa372919(v=vs.85).aspx
This is where the structured storage is. You'll see something like Disk1.cab as the Name (PK) and binary data. The data is a CAB file with the file entry in the cab matching the File.File column. From there you can use the File.FileName column to get the short name and long name (you'll want the long name no doubt) and do a joint to the Component table to get the directory table ID.
You'll also need to recurse the directory table to build the tree of directories and know where to put the files.
Fun stuff. There's some libraries in C# that make this WAY simpler. Or just call msiexec /a as Phil says. :)
The most straightforward to extract all the files to some location is to install the product in "advertised" mode. If you do a:
msiexec /a [path to msi] TARGETDIR=[some folder]
you'll see what happens.
In C++ call MsiInstallProduct () with that command line.
You have gotten many good answers already, including the use of dark.exe from the WiX toolkit. By downloading the WiX source code you should be able to get the code you need ready-made from there. I assume you may already have done this.
Chris has already linked to the DTF code you can check, but here is a link directly to dark.exe as well: https://github.com/wixtoolset/wix3/tree/develop/src/tools/dark. I would try both. This is C#, you seem to want native.
UPDATE: Before I get to the Win32 features you can use, check out this little summary of the C# DTF features: How to programmatically read the properties inside an MSI file?
Native Win32 functions: The database functions to deal with an MSI file can be found on MSDN (this is to deal with the MSI file as a database). There are also MSI Installer Functions (used to deal with the MSI file as an actual installer).
You can certainly find good examples of native code for this with a good Google search. Have fun!
BTW: It would help with a description of the actual problem you are trying to solve as well as what you need technically. There could - as always - be less involved ways to achieve what you need. Unless you are writing a security software or malware scanner or something super-involved.
And so it is clear: WiX's dark.exe fully decompiles MSI files into WiX source files and the resource files used to build them - you can then text and binary compare the various types of content (text compare for tables, binary compare for binaries, etc...). The process to do so via command line is described in the following answer: How can I compare the content of two (or more) MSI files? (this is about comparing MSI files, but one option to do so is to decompile them - see section on dark.exe - just for reference for others who find your question).
I like to link things together so we can find content easily at a later point in time. Strictly speaking it doesn't seem necessary here, you have what you need I think but others could perhaps benefit from some further links. Here are some related links:
Extract MSI from EXE.
What is the purpose of administrative installation initiated using msiexec /a?
How do I extract files from an MSI package? (explains why you should not use 7-Zip to extract).
My question should be very simple to answer for anyone not being a self-taught newbie like me...
On this page is a cheatsheet concerning a function to be used in GIS/DB environnement : http://www.bostongis.com/pgsql2shp_shp2pgsql_quickguide.bqg
I would like to create a script allowing users to just have to click on it to launch the process, given the proper datas. But I don't understand how to use this. It obviously doesn't work in a Python console, nor directly in the windows console. How is it supposed to work ? What language is this ?
Thanks
shp2pgsql is indeed a command line tool. It comes with your PostgreSQL/PostGIS installation (usually) and, if not accessible via PATH-variable, can (usually) be run from within the /bin-folder in your PostgreSQL-Installation. You can also always 'make' the programm from source in any location yourself, if needed.
EDIT:
One way to set up a script (independent of whether you use it within qgis own python environment or not) would be to use Pythons subprocess (or os.system) module (check related question here) to write to shell and execute shp2pgsql.
A slightly more sophisitcated solution to (batch) insert (multiple) shapefiles via script could be to implement ogr2ogr via gdal/ogr module within python (check this blog). That, however, would require a working installation of the gdal core library, and the respective Python bindings (at least to use outside of QGIS Python environment, where it is pre-installed AFAIK), which can be tiresome at times. Once installed correctly, it offers a powerful (I dare say almighty) toolset for geodata management and manipulation via Python, though.
Apart from that, the blog link I provided also states the implementation of a batch insert script/tool (which operates ogr2ogr) in qgis 2.8 toolbox...maybe that can help you, either with your work directly or (via sourcecode) to point you in the direction of creating your own tool.
I am learning Tcl/Tk, and I have been following a tutorial to a point that I am moving to Tk. All the files in the tutorial use Tk commands (such as "button") right away, without having "package require Tk" written in the .tcl files. I am executing this from the console that accepts user input with "%" in the front.
If the tutorials don't have that "package require Tk", am I missing something? How can we have Tk without having to write "package require Tk" in all the files, or am I doing it wrong?
If you've associated the file extension .tcl with the wish executable (modulo possible extensions and version info, of course) then you'll effectively have a package require Tk done for you before your script starts running. This is not recommended as being good practice in modern code — make your dependencies explicit, please — but it works just fine and many people do it.
It's not recommended that you force the matter by editing Tcl's startup scripts. After all, there's applications out there that use Tcl without Tk.
I'm doing some Linux kernel development, and I'm trying to use Netbeans. Despite declared support for Make-based C projects, I cannot create a fully functional Netbeans project. This is despite compiling having Netbeans analyze a kernel binary that was compiled with full debugging information. Problems include:
files are wrongly excluded: Some files are incorrectly greyed out in the project, which means Netbeans does not believe they should be included in the project, when in fact they are compiled into the kernel. The main problem is that Netbeans will miss any definitions that exist in these files, such as data structures and functions, but also miss macro definitions.
cannot find definitions: Pretty self-explanatory - often times, Netbeans cannot find the definition of something. This is partly a result of the above problem.
can't find header files: self-explanatory
I'm wondering if anyone has had success with setting up Netbeans for Linux kernel development, and if so, what settings they used. Ultimately, I'm looking for Netbeans to be able to either parse the Makefile (preferred) or extract the debug information from the binary (less desirable, since this can significantly slow down compilation), and automatically determine which files are actually compiled and which macros are actually defined. Then, based on this, I would like to be able to find the definitions of any data structure, variable, function, etc. and have complete auto-completion.
Let me preface this question with some points:
I'm not interested in solutions involving Vim/Emacs. I know some people like them, but I'm not one of them.
As the title suggest, I would be also happy to know how to set-up Eclipse to do what I need
While I would prefer perfect coverage, something that only misses one in a million definitions is obviously fine
SO's useful "Related Questions" feature has informed me that the following question is related: https://stackoverflow.com/questions/149321/what-ide-would-be-good-for-linux-kernel-driver-development. Upon reading it, the question is more of a comparison between IDE's, whereas I'm looking for how to set-up a particular IDE. Even so, the user Wade Mealing seems to have some expertise in working with Eclipse on this kind of development, so I would certainly appreciate his (and of course all of your) answers.
Cheers
Eclipse seems to be pretty popular for Linux kernel development:
http://cdtdoug.blogspot.com/2008/12/linux-kernel-debugging-with-cdt.html
http://jakob.engbloms.se/archives/338
http://revver.com/video/606464/debugging-the-linux-kernel-using-eclipsecdt-and-qemu/
I previously wrote up an answer. Now I come up with all the details of the solution and would like to share it. Unfortunately stackoverflow does not allow me to edit the previous answer. So I write it up in this new answer.
It involves a few steps.
[1] The first step is to modify linux scripts to leave dep files in. By default after using them in the build, those dep files are removed. Those dep files contains exact dependency information about which other files a C file depends. We need them to create a list of all the files involved in a build. Thus, modify files under linux-x.y.z/scripts to make them not to remove the dep files like this:
linux-3.1.2/scripts
Kbuild.include: echo do_not_rm1 rm -f $(depfile);
Makefile.build: echo do_not_rm2 rm -f $(depfile);
The other steps are detailed in my github code project file https://github.com/minghuascode/Nbk/blob/master/note-nbkparse. Roughly you do:
[2] Configure with your method of configuration, but be sure use "O=" option to build the obj files into a separate directory.
[3] Then use the same "O=" option and "V=1" option to build linux, and save make output into a file.
[4] Run my nbkparse script from the above github project. It does:
[4.1] Read in the make log file, and the dep files. Generate a mirroring command.
[4.2] Run the mirroring command to hard-link the relevant source files into a separate tree, and generate a make-log file for NetBeans to use.
Now create a NetBeans C project using the mirrored source tree and the generated log file. NetBeans should be able to resolve all the kernel symbols. And you will only see the files involved in the build.
The Eclipse wiki has a page about this: HowTo use the CDT to navigate Linux kernel source
I have been doing some embedded linux development. Including kernel module development and have imported the entire linux kernel source code into Eclipse, as a separate project. I have been building the kernel itself outside of Eclipse(so far), but I don't any reason why I shouldn't be able to set up the build environment within Eclipse to build the kernel. For my projects, as long as I setup the PATH properties to point to the appropriate linux source include directories, it seems to be pretty good about name completion for struct fields, etc.
I can't really comment, on if it is picking up the correct defines and not greying out the correspond sections, as I haven't really paid to much attention to the files within the kernel itself.(so far)
I was also wondering about using Netbeans as a linux 'C' IDE, as I do prefer Netbean's for Java GUI development.
I think this would work (done each step for various projects):
[1] Modify kernel build scripts to leave .d files. By default they are removed.
[2] Log the build process to a file.
[3] Write a script to parse the build log.
[3.1] From the build log, you know every .c files.
[3.2] From the .c file, you know which is the corresponding .d file.
[3.3] Look into .d files to find out all the included .h files.
[3.4] Form a complete .c and .h file list.
[4] Now create a new dir, and use "ln -s" or "ln" to pick files of interest.
Now, create a Netbeans project for existing source code in the [4].
Configure code assistance to use make-log file. You should see
exactly the effective source code as when you build it at [2].
Some explanations to the above steps:
At [2], do a real build so the log file contains the exact files and flags of interest.
Later netbeans will be able to use the exact flags to parse.
At [4], pick only the files you want to see. Incorporating the whole kernel tree into netbeans will be unpractical.
There is a trick to parsing .d files: Many of the depended items are not real paths to a .h file, they are a modified entry for part of the linux config sections in the auto config file. You may need to reverse the modification to figure out which is the real header file.
Actually there is a topic on netbeans site. This is the discussion url: http://forums.netbeans.org/ntopic3075.html . And there is a wiki page linked from the discussion: wiki.netbeans.org/CNDLinuxKernel . Basically it asks you to prefix make with CFLAGS="-g3 -gdwarf-2" .
I found this link very helpful in setting up proper indexing in Eclipse. It requires running a script to alter Eclipse environment to match your kernel options, in my case
$ autoconf-to-eclipse.py ./include/generated/autoconf.h .
An illustrated guide to indexing the linux kernel in eclipse