Using mercurial, I added a new file and wrote code in it, then deleted that file. Can I retrieve it? - mercurial

Pretty much the title. I've looked at a lot of similar questions asked here, and I can't seem to find something that applies.
Started by syncing with HEAD. Created a few new files. Filled in those files, they were being tracked at this point. I then not only deleted the files, but also removed them from being tracked (because of stupid UI). According to my understanding, those files are gone for good, but I thought I'd check with people who are smarter than me: Is it possible to retrieve them?

Mercurial does not store uncommitted changes, so if you did not commit the files then they are lost.
If you did commit them, then hg update -C will restore them (and all other files --- make sure there are no other changes you haven't committed and want to keep) to the latest commit for your working dir.

Related

Mercurial ignored file causes abort when trying to update to previous revision

Here's my scenario: When I initially created my Mercurial repo, I used hg add to add all *.pl *.sh and *.sql scripts to the repo. I later learned how to use the .hgignore file to exclude other files from the repo. One of the files I needed to exclude was a *.sql file that is generated by a script, so it is essentially a data file that constantly changes when the script runs that produces it; thus, I added it explicitly to the .hgignore file a few revisions ago.
Today, I want to update to a prior revision before this *.sql file was added to the .hgignore, so that I can create a branch off of it. However, when I try to update the working directory to this prior version, I get the following error:
a.sql: untracked file differs
abort: untracked files in working directory differ from files in requested revision
I know that one way I could get around this problem is to delete the file before trying to update to the prior revision, either by manually deleting it or using hg update --clean --check.
That may work in this particular case, since the file is auto-generated by a script each time, and so I don't care about the data that is currently in it.
However, I'm trying to find out what is the safe way people would generally handle this situation when they decide to ignore a file set (like a set of data files that aren't auto-generated) and need to return to a previous revision before they were marked to be ignored, especially if they wanted to retain the most current content in those file sets while still being able to view earlier revisions of files that Mercurial is actively tracking.
I've also considered that you could backup the files, but I think that is only a reasonable solution if this is a one-off case. If you want the ability to hg update to previous revisions on a frequent at-whim basis, then it becomes quite tedious to backup the data each time before you update to a earlier revision (it's also not a reliable way to guarantee that others may not delete the data that isn't being tracked in the repo).
Thanks for the help.
However, I'm trying to find out what is the safe way people would generally handle this situation when they decide to ignore a file set (like a set of data files that aren't auto-generated) and need to return to a previous revision before they were marked to be ignored, especially if they wanted to retain the most current content in those file sets while still being able to view earlier revisions of files that Mercurial is actively tracking.
It depends.
If you have exclusive control over this repository, and have the practical ability to require everyone to re-clone from it, then you can use hg convert to exclude the files from the old revisions. This is by far the cleanest option, but it will change the revision identifiers (hashes) for those revisions and all of their topological descendants. This is why everyone has to re-clone; their old clones will not interact properly with the new repository.
If you can't do that, you can copy the files somewhere else (you do have backups already, right?), clobber the originals with the old versions, and then restore them from your copy. This has to be done whenever you check the files out, so it is definitely suboptimal. You may be able to make this slightly easier by keeping the files outside the repository and checking in symlinks to the files, but you'll still have to fix up the symlinks whenever you checkout an old version.
However, what you describe is not the normal use case for Mercurial. Typically, untracked files are autogenerated, or at least able to be regenerated from tracked files. The operating assumption is that untracked files are not important and can be discarded at any time. Mercurial doesn't actually do this, because that would be rude, but neither does it make any special effort to preserve them when (for example) you make a bundle of the repository.
If you need to deal with versioning of object files, it is typical to store them in a separate artifact repository or some other system. This can be more difficult to manage because you have to reunite the binaries with the source code when you do a build. But it is much more robust than keeping the binaries loose in the repository and hoping they won't get accidentally overwritten or deleted.
Another option is to collapse the binary to text and then place the text under version control. This is always possible (e.g. take a hexdump) but may or may not be practical or reasonable, depending on the file format. For a compressed file format (e.g. tarballs, most image files, etc.) the hexdump is not going to be any easier to 3-way merge than the original binary, so there's little point in it. Similarly, if the binary is huge, the hexdump will be huge too. On the other hand, if a binary is compiled from source code, it is entirely normal to store the source and discard the binary. For something structured like an SQLite database, you might try storing an SQL script which will generate the database. For a zip file or tarball, store the contents. And so on. All of these things can be regenerated using make or a similar tool whenever you check things out, and you can automate this with a repo hook.

Pulling without merging

I'm trying to make a crontab that pulls and makes a repository every day for me, but whenever i do that and the repository merges the crontab gets stuck.
Is there a way to pull without prompting a merge and without deleting my code?
Is there a way to pull without prompting a merge
Just hg pull by itself does not merge, nor does it ask the user for anything. The local repository will be added to, but the local working directory will not be touched. Nothing will be deleted.
If your .hgrc file is using a [defaults] section, you might be silently adding the -u/--update option without realizing it. That option tries to automatically do an update. If that's the case, then don't use defaults sections.
If this doesn't answer your question, then show us exactly what commands your cron entry is running, what the output is, where it "gets stuck" (is SSH asking for authentication credentials?), and which part you're trying to avoid.
The literal answer to how do you pull without merging is you hg fetch which gets the new remote changesets but doesn't update any files in your working directory. It sounds like what you're really asking though is "how do I update to tip and throw away any local changes?". If that's what you're going for you'd do:
hg fetch # gets new changesets
hg update --clean # update to latest files THROWING AWAY LOCAL CHANGES
Is that what you're going for?

Pushing/Pulling specific files/folders in Mercurial

I am (still) trying to completely migrate our company's SVN to HG.
For the most part I've succeeded, but we ran across a problem.
Our codebase has over 30 different projects, each one on its folder.
I've been asked multiple times how to commit and then push specific files to our central repository instead of being forced to commit everything everywhere to then push it, it's certainly annoying. Not being able to pull only specific projects is also an nuisance.
Is there any way to handle this like we used to in SVN? Where we could just commit what we wanted and not everything, and update only what was necessary.
Thank you.
A major difference between SVN and Mercurial is that you should have one repository per project in Mercurial.
You can change your repository to be multiple repositories using the convert extension.
Like Steve Kaye said you should create one repo per project, but as well you may want to create one master repo and include all your projects as subrepos This will allow svn like behavior of getting a copy of everything.

Keep MySQL files as 'per-project'?

Currently I work at two places - at work and at home. I have a problem with keeping up to date. With files I solved my problem (I use private SVN and commit from phpStorm), but I still have no idea about MySQL. Currently, I just export my tables when I'm going out, but it isn't much of a good way (I know myself, sooner or later I'll forget to do it).
My question is: can I store MySQL data files on per-project basis, so I could commit it into SVN along with other files?
You could make use of a post commit hook that dumps the database, and a hook before update the inserts the dump.

How can I commit a set of files only once in Mercurial?

I have some files I'd like to add to have them as a "backup". The thing is, I'd like to commit them only one time, and then, I'd like for Mercurial to don't track them anymore ( don't notify me if they're changed, and don't commit them on other commits ).
Basically, something like this:
hg add my_folder
hg commit -m "added first version of my_folder"
Then, after a while, the contents of that folder might change. And if I commit other files, the new version of that folder will get commited as well. This is something I'd like to avoid. Is it possible, without specifying directly which files I want to commit?
I've never seen any option in Mercurial that might allow that... but why not simply copy them elsewhere ?
I mean, what's the point of using a Version Tracking System if you don't need versioning on these items anyway ?
We ran into a similar case with binary documents ('.doc', images, etc...) and finally decided to commit them on a separate repository, dedicated to those.
I think the traditional way of doing this is to commit files named something like "file.ext.default", and just inform users that they should copy the defaults and modify the copies.
VCSs aren't backup sysytems. consider using a proper backup mechanism.
having said that you should be able to do this using hooks, there are many ways you could do this but ACLs would be an obvious one assuming a remote server