# setup_git_directory_gently contract question? 5 messages from 2008-05-27 to 2008-05-28. Participants: Ciprian Dorin Craciun, Nguyen Thai Ngoc Duy, Junio C Hamano. Thread: https://gitlist.dev/t/13690 ## Ciprian Dorin Craciun, 2008-05-27 14:10 Subject: setup_git_directory_gently contract question? Message-ID: <8e04b5820805270710v3a06e5c2if2dcf3b94ef40c1f@mail.gmail.com> URL: https://gitlist.dev/e/8e04b5820805270710v3a06e5c2if2dcf3b94ef40c1f%40mail.gmail.com ``` Is the function setup_git_directory_gently supposed to change the current working directory, or should it keep the initial one? What is the meaning of nongit_ok? Because if I use nongit_ok != NULL, but *nongit_ok == 1, this function changes the current working directory to the top of the worktree directory. Thanks, Ciprian Craciun. ``` ## Ciprian Dorin Craciun, 2008-05-27 14:35 Subject: Re: setup_git_directory_gently contract question? Message-ID: <8e04b5820805270735m24ae4966x932ae610606d6e64@mail.gmail.com> URL: https://gitlist.dev/e/8e04b5820805270735m24ae4966x932ae610606d6e64%40mail.gmail.com In-Reply-To: <8e04b5820805270710v3a06e5c2if2dcf3b94ef40c1f@mail.gmail.com> ``` Or another question: how can I obtain the git directory (.git) (absolute) path without updating the current working directory? Thanks, Ciprian Craciun. On Tue, May 27, 2008 at 5:10 PM, Ciprian Dorin Craciun wrote: > Is the function setup_git_directory_gently supposed to change the > current working directory, or should it keep the initial one? > What is the meaning of nongit_ok? > > Because if I use nongit_ok != NULL, but *nongit_ok == 1, this > function changes the current working directory to the top of the > worktree directory. > > Thanks, > Ciprian Craciun. ``` ## Nguyen Thai Ngoc Duy, 2008-05-27 15:32 Subject: Re: setup_git_directory_gently contract question? Message-ID: URL: https://gitlist.dev/e/fcaeb9bf0805270832lc779a37gd9e58d0790981788%40mail.gmail.com In-Reply-To: <8e04b5820805270710v3a06e5c2if2dcf3b94ef40c1f@mail.gmail.com> ``` On Tue, May 27, 2008 at 9:10 PM, Ciprian Dorin Craciun wrote: > Is the function setup_git_directory_gently supposed to change the > current working directory, or should it keep the initial one? It will change if it finds a worktree. > What is the meaning of nongit_ok? Setting it to a non null pointer prevents git from die() when no git repository can be found. > Because if I use nongit_ok != NULL, but *nongit_ok == 1, this > function changes the current working directory to the top of the > worktree directory. It returns a directory prefix so that you can still know the original current working directory. You can do as following to have current directory "unchanged" prefix = setup_git_directory_gently(&nongit_ok); if (prefix) chdir(prefix) > Thanks, > Ciprian Craciun. > -- > To unsubscribe from this list: send the line "unsubscribe git" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Duy ``` ## Junio C Hamano, 2008-05-27 22:46 Subject: Re: setup_git_directory_gently contract question? Message-ID: <7vmymbz7on.fsf@gitster.siamese.dyndns.org> URL: https://gitlist.dev/e/7vmymbz7on.fsf%40gitster.siamese.dyndns.org In-Reply-To: <8e04b5820805270710v3a06e5c2if2dcf3b94ef40c1f@mail.gmail.com> ``` "Ciprian Dorin Craciun" writes: > Is the function setup_git_directory_gently supposed to change the > current working directory, or should it keep the initial one? > What is the meaning of nongit_ok? Most commands that work from subdirectory use setup_git_directory() interface, because major parts of the guts of the git internal want you to be at the top of the work tree (e.g. so that you grab a path out of the index, and be able to open(2) or lstat(2) that path). A normal sequence for a command is: (1) use setup_git_directory() to learn "prefix", (2) use get_pathspec() and/or prefix_path() to add "prefix" to the paths given from the command to make it a path relative to the work tree, (3) do its thing. setup_git_directory() chdir's up to the top of the work tree for this reason. Some commands can optionally work from even outside a git repository, but they would want to operate the same way as other comands, when they are started within a git repository. In such a case, you use "gently" variant, and give a pointer to int to store an additional return value to signal you if you are inside a git repository or outside. * When NULL is given as nongit_ok to gently(), it does not behave gentle at all. Outside a git repository it dies loudly. * If you are inside a git repository, it behaves pretty much the same as setup_git_directory(). "*nongit_ok" is set to zero to signal that you are inside a git repository. * If you are outside a git repository, *nongit_ok is set to non-zero so that the caller can tell that it is not in any git repository's work tree. There is no need to chdir (nor a sensible place to chdir to) in this case, so it doesn't. The caller thinks of the parameter as "are we operating in non-git mode?" boolean, and the callee (i.e. setup_git_directory_gently()) thinks of it as "is it ok to be called outside a git repository?" (if it is NULL, the caller expects to be inside a repository and wants it to barf otherwise). That is why caller's variable are often called "int nongit", and the callee's parameter is called "int *nongit_ok". ``` ## Ciprian Dorin Craciun, 2008-05-28 07:14 Subject: Re: setup_git_directory_gently contract question? Message-ID: <8e04b5820805280014m6fc635tf91ae20d9b9a5c91@mail.gmail.com> URL: https://gitlist.dev/e/8e04b5820805280014m6fc635tf91ae20d9b9a5c91%40mail.gmail.com In-Reply-To: <7vmymbz7on.fsf@gitster.siamese.dyndns.org> ``` On Wed, May 28, 2008 at 1:46 AM, Junio C Hamano wrote: > "Ciprian Dorin Craciun" writes: > >> Is the function setup_git_directory_gently supposed to change the >> current working directory, or should it keep the initial one? >> What is the meaning of nongit_ok? > > Most commands that work from subdirectory use setup_git_directory() > interface, because major parts of the guts of the git internal want you to > be at the top of the work tree (e.g. so that you grab a path out of the > index, and be able to open(2) or lstat(2) that path). A normal sequence > for a command is: (1) use setup_git_directory() to learn "prefix", (2) use > get_pathspec() and/or prefix_path() to add "prefix" to the paths given > from the command to make it a path relative to the work tree, (3) do its > thing. setup_git_directory() chdir's up to the top of the work tree for > this reason. > > Some commands can optionally work from even outside a git repository, but > they would want to operate the same way as other comands, when they are > started within a git repository. In such a case, you use "gently" > variant, and give a pointer to int to store an additional return value to > signal you if you are inside a git repository or outside. > > * When NULL is given as nongit_ok to gently(), it does not behave gentle > at all. Outside a git repository it dies loudly. > > * If you are inside a git repository, it behaves pretty much the same as > setup_git_directory(). "*nongit_ok" is set to zero to signal that you > are inside a git repository. > > * If you are outside a git repository, *nongit_ok is set to non-zero so > that the caller can tell that it is not in any git repository's work > tree. There is no need to chdir (nor a sensible place to chdir to) in > this case, so it doesn't. > > The caller thinks of the parameter as "are we operating in non-git mode?" > boolean, and the callee (i.e. setup_git_directory_gently()) thinks of it > as "is it ok to be called outside a git repository?" (if it is NULL, the > caller expects to be inside a repository and wants it to barf otherwise). > That is why caller's variable are often called "int nongit", and the > callee's parameter is called "int *nongit_ok". Thank you for your complete answer. I would propose that these comments to be added to the Documentation/technical/... directory, (or in the setup.c file), so that further developers will have this information. Thanks again, Ciprian. ```