Now I'm trying to use .dir-locals.el for my own projects.
However it is saved at the end of init.el whenever I choose to save it permanently.
I'd like to change it to an another seperate file - eg ~/mydirlocals.el.
Please let me know what could be the solution for this.
PS : I've already tried to change custom file to a seperate one. But unfortunately it saved my dir-local variables with other custom variables.
I want to avoid this and save my dir-locals variables in a completely seperate file.
You can't use the customize interface to update .dir-locals.el files. Customize is for your own config. If you want to edit/update a directory-local variables file, you need to either edit that file directly, or use M-x add-dir-local-variable.
The latter command will prompt you for the details. Note that no default value is offered at the prompt for the value of the variable, but that you can type M-n or <down> to obtain the variable's value in the current buffer.
Note also that the command does not ask which directory the variables are local to -- it will create/update a .dir-locals.el file in the default directory for the current buffer. Issuing the command from a dired buffer for the intended directory is a safe approach, naturally, but you may wish to do so from a buffer in the mode for which you wish to add variables -- that way the default suggestion for the mode, and the current values of the variables in question, will be more useful to you.
(If there is no file of the appropriate type in the directory, you can always C-xC-f a new/unsaved buffer of an appropriate filename, use add-dir-local-variable as many times as necessary, and then when you're done just kill any new buffers you created without saving them.)
That all said, I'm still not 100% sure what your requirement is, as your question is a little confused; but you may also like to know that you can use directory-local variables without a .dir-locals.el file at all, as you can alternatively configure them entirely in your init file.
See https://www.emacswiki.org/emacs/DirectoryVariables for details and examples of that.
Disclaimer: I haven't used dir-local vars, but I have used file-local vars. I'm guessing dir-locals work the same.
The local variables aren't getting saved at the end of init.el or custom.el, the safe values are. As in, Emacs doesn't trust them by default, unless they match some sort of predicate indicating they're OK. This is a good policy, because file and dir locals can cause Emacs to run arbitrary code just by opening a file. When you apply permanently, you're telling Emacs that that value is safe; it basically just makes a predicate that matches the exact value and stores that with customize.
If you want to prevent the prompt (and thus the saving), you need mark the variables as safe with your own predicate.
For example, I set
(put 'adaptive-wrap-extra-indent 'safe-local-variable 'integerp)
which means that adaptive-wrap-extra-indent is OK as long as it's an integer. I know this is OK because I added that variable to the adaptive-wrap package (though I didn't know about safe locals at the time; I submitted a bug to fix it, which appears to be ignored). Clearly you can use any predicate, including (lambda (x) t), though I'd recommend against that.
Related
I'm using add_custom_command() to generate some files. ninja clean removes them, as it should. One of the files is intended as a default/example implementation, to be modified by the user. It is only generated if it does not already exist. I would like for ninja clean not to remove this file.
I have tried a number of things but without success:
add_custom_target(): CMake complains about the missing file unless I name it in BYPRODUCTS, but doing this also leads to removal on clean
set_file_properties(... GENERATED FALSE) doesn't work because CMake complains about the file missing.
set_directory_properties() failed in a similar way: "folder doesn't exist or not yet processed" (it does exist)
I previously generated the example implementation and just let the user copy it or model their code on it. This works, but isn't entirely satisfactory. Is my use-case so unlikely that CMake doesn't support it?
I am afraid you requirment (conceptually, have make create something which make clean does not remove) is rather unusual. I can think of two potential solutions/workarounds.
One, move the file's generation to CMake time. That is, create it using execute_process() instead of add_custom_command(). This may or may not be possible, based on whether the file-generation process (the current custom command) depends on the rest of the build or not.
Two, totally hide the example file's existence from CMake. That is, have the custom command also generate some other file (maybe just a timestamp file) and have its driving custom target depend on that one instead. Do not list the example file as ither the custom command's dependency, output, or byproduct. That way, nothing will depend on it and neither CMake nor Ninja should not care whether it exists or not, so they will not complain or try to clean it up.
If it is an example for the user, it should not be in your build folder, but in the install folder. I don't see why you would need add_custom_command or the other commands you listed.
Therefore, you have to provide install() instructions.
You can then call make install. Cleaning will not remove those and only installing again will overwrite them if necessary.
For those, who come here a long time after the original question was asked (like me), I'll write my solution:
The tool called in add_custom_command generates two files with identical content:
one that is saved in sources, never mentioned anywhere
and one that's marked as byproduct, and then is depended on
So the first one is the file we wanted in the first place.
And the second one is actually used in build process, and gets deleted on clean.
For me the issue is that I actually want to save generated files in VCS so I can track changes. And this approach gives ne what I need.
I am working with multiple processes that write to the same directory.
I have a directory dir1/
My process creates a file a.txt under dir1/. However the other process creates a-temp1.txt and renames it to a.txt. I don't have control over the other process since that code comes from a library. Can I prevent a-temp.txt from being renamed?
There's nothing you can do that the other process can't undo. Your best hope (other than changing your program to work sanely) is that the other process doesn't try too hard to do the rename. That is, it tries the simple approach and gives up if that fails.
In particular, you can set the UF_IMMUTABLE flag on either file and that will prevent one from being renamed to replace the other. You can set the flag using chflags(). Using Cocoa, you could also use [someURL setResourceValue:#YES forKey:NSURLIsUserImmutableKey error:NULL].
Keep in mind that you won't be able to change the file in any other way, either, until that flag is removed. If the other process is determined to rename the file, it has permission to remove the flag just like your process does.
Also keep in mind that a system such as this is inherently race-prone.
You really ought to use separate names for the files, or separate directories, or ditch that library that doesn't give you the control you need.
Set the user immutable flag chflags(...,uchg). This will keep the other process from changing your file unless it takes action to clear the bit. Of course I don't know how the other process will react to you putting things in it's way, but that wasn't the question.
You can use chflags() on an HFS+ (Mac OS X) file system to set the UF_APPEND attribute. (Do a man 2 chflags.) That will permit appending to the file, but not deleting or renaming, even by the same user.
You can, but it unlikely will solve your problem. I strongly suspect this is an X-Y problem, and almost certainly the correct solution is to redesign some part of this system entirely, probably by changing your file names, using unique temporary files, moving to another directory, or reworking the usage of the library (libraries only do what callers tell them to do; and libraries are just code anyway). You shouldn't try to defeat another process; you're all working for the same user.
All that said, sure, you can prevent your own userid from renaming over file. Just deny yourself permission. You can modify the file:
chmod 400 a.txt
That says that you can read the file but may not write it. However, if you already have an open file handle, you may continue to use it (so you can keep writing to the file, even though another process running as the same user may not).
Similarly, you may change permissions on the directory:
chmod 500 .
This would prevent the rename because file names are kept in the directory.
I am interested in any IDE (or even a script) that is capable of refactoring Go source code for variable renaming. For example in Eclipse for Java, one can select a variable, an object or a class, then to rename it and it gets automatically renamed in all the files in the project. This feature is very useful if automatic string replacement may cause substring collisions.
If you're interested in a script, use gofmt with -r flag. Like this:
gofmt -w -r 'OldFoo -> Foo' foopackage
From the docs:
Without an explicit path, it processes the standard input. Given a file, it operates on that file; given a directory, it operates on all .go files in that directory, recursively. (Files starting with a period are ignored.) By default, gofmt prints the reformatted sources to standard output.
EDIT: Today there are better tools for that: gorename for renaming and eg for general refactoring.
The gorename tool performs precise type-safe renaming of identifiers in Go source code.
What reasons could there be for the following strange behaviour, and how might I track down the issues?
We use a combination of make files and msbuild.
I have a project which needs to be strongly named. I was previously setting the snk to use in the project file like this:
<AssemblyOriginatorKeyFile>$(EnvironmentVariable)TheKeyName.snk</AssemblyOriginatorKeyFile>
where EnvironmentVariable was defined in the batch file that launched the shell for the build like this:
set EnvironmentVariable='SomePath'
and this worked ok. Now I need the string name key to be able to be changed, so it can be different on the dev machine and the release build server. There is a variable which exists to hold the full path to the strong name key file, called StrongNameKeyFile. This is defined in the msbuild environment, and if I put some text output in the targets or properties files that are included as part of the msbuild task which build the project then I can see that this StrongNameKeyFile points to the correct location. So I changed the csproj to have this instead:
<AssemblyOriginatorKeyFile>$(StrongNameKeyFile)</AssemblyOriginatorKeyFile>
but when I try and compile this is evaluating to empty and no /keyfile is specified during the build.
We also have variable defined in the make files and these can be accessed in the csproj as well. These are used to point to the locations of referenced dlls, so that they can be different on dev and build machines. I know that these are set as the references come out correctly and everything compiles, but if I try and use one of these variables in the AssemblyOriginatorKeyFile element then it evaluates to empty in that element, but works in the reference element.
Why might this be? Is AssemblyOriginatorKeyFile treated specially somehow? How can I go about tracking the cause of this down?
There's no good reason why this should happen - as you know it normally Just Works; it's likely to be something in the chain dropping it on the floor.
One thing to try is explicitly passing it via /p:StrongNameKeyFile=XX - that would eliminate environment variables and the correct propagation thereof from your inquiries.
Another potential thing is that something is clobbering the variable as the name is used vy something else?
Run with /v:diag and you'll get dumps of all the inputs and/or variables as they change.
Or if on V4, use the MSBuild Debugger
And buy the Hashimi et al MSBuild book
As a practice exercise at my college we have to make a simple room booking system, complete with its own config file. We're not allowed to use the one built into VB.NET (the professor wants us to adapt to not relying on things like that) so I've made my own. This is a sample:
// Config file.
// First column is the variable name that will be used to
// reference the value in the second column. Seperate each
// setting with a new line.
MasterUser Chris
DatabasePath C:\Users\Chris\Desktop\Project.mdb
Comments in the file are pretty self-explanatory. I can parse the file fine, but what I'm having trouble with is making a variable the same name as whats in the first column. For example I need to make a variable called MasterUser and one called DatabasePath that holds Chris and C:\Users\Chris\Desktop\Project.mdb as values respectively. But I have no idea how to make a variable called that.
Any help would be cool, thanks. :)
EDIT: You can't see it from the code view here, but the variable name and value in the config file are separated by a tab :)
You might want to consider using a better format for your configuration file, like XML. This will give you a lot more library support for parsing and searching within the file... that said, in this simple case, it looks like you just need a simple Dictionary(Of String, String) which probably won't make a lot of sense if you haven't learned about Generics yet :)
Basically you can load values in like this:
Dim settings As New Dictionary(Of String, String)
settings.Add("MasterUser", "Chris")
settings.Add("DatabasePath", "C:\Users\Chris\Desktop\Project.mdb")
Then when you want to retrieve a value based on the key in the dictionary, you can do it like this:
Dim master As String = settings("MasterUser") ' master = "Chris"
I hope that helps clear things up.
Well, in the strict sense, you cannot "Make a variable named from file data" in most compiled languages. What you could do is to make a name-value association set (that's a Dictionary in .Net) and add entries to it based on what you read from a file.
However, what most programmers do is to "invert" that logic: as you code reads each line, it just does a series of IF's on the Name to see if it is recognized, and if so then just assings it to the corresponding predefined variable of the same name.
There are formats & libraries specially made for this (like XML, that's why the built in configs use it), but that might still be the kind of thing that you are not supposed to rely on.
Since your configuration file is not compiled into your code in any meaningful way, you aren't going to be able to create a variable (that is, a strongly-typed property or field on a class) dynamically. You have a couple of options.
If you want to keep your configuration file format:
Create a class that contains all possible configuration keys as properties. Give that class a Load() method that knows how to parse a file into the class.
Use a Dictionary -- either the Generics version or good old fashioned System.Collections.Dictionary. You'll retrieve elements with string keys.
If you're willing to change your configuration file format to XML, then you can use Serialization. This frees you from having to maintain a parser, but it requires a little bit more setup.
See here for my answer to another SO's question using nini and where to download it from. Essentially nini is a simple INI read/write library for configuration files. The question that remains to be seen is will your professor allow this inclusion of 3rd party open source?
Hope this helps,
Best regards,
Tom.