[PATCH v2] ident: check /etc/mailname if email is unknown
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Oct 3, 2011, 06:16 UTC
- Message-ID
- <20111003061633.GB17289@elie>
- In-Reply-To
- <7v8vp2iqvc.fsf@alter.siamese.dyndns.org>
Before falling back to gethostname(), check /etc/mailname if GIT_AUTHOR_EMAIL is not set in the environment or through config files. Only fall back if /etc/mailname cannot be opened or read.
The /etc/mailname convention comes from Debian policy section 11.6 ("mail transport, delivery and user agents"), though maybe it could be useful sometimes on other machines, too. The lack of this support was noticed by various people in different ways:
- Ian observed that git was choosing the address 'ian@anarres.relativity.greenend.org.uk' rather than 'ian@davenant.greenend.org.uk' as it should have done.
- Jonathan noticed that operations like "git commit" were needlessly slow when using a resolver that was slow to handle reverse DNS lookups.
Alas, after this patch, if /etc/mailname is set up and the [user] name and email configuration aren't, the committer email will not provide a charming reminder of which machine commits were made on any more. But I think it's worth it.
Mechanics: the functionality of reading mailname goes in its own function, so people who care about other distros can easily add an implementation to a similar location without making copy_email() too long and losing clarity. While at it, we split out the fallback default logic that does gethostname(), too (rearranging it a little and adding a check for errors from gethostname while at it).
Based on a patch by Gerrit Pape <pape@smarden.org>.
Requested-by: Ian Jackson <ijackson@chiark.greenend.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Improved-by: Junio C Hamano <gitster@pobox.com> --- Junio C Hamano wrote:
> I do not think this would hurt, even though I see /etc/mailname on only > one of my boxes (i.e. Debian). For maintainability for the future, > however, I would prefer to see the above hunk separated into a helper > function to keep addition to copy_email() to the minimum, e.g.
Makes sense. How about this?
Documentation/git-commit-tree.txt | 8 ++++- ident.c | 66 +++++++++++++++++++++++++++++------- 2 files changed, 60 insertions(+), 14 deletions(-)
diff --git a/Documentation/git-commit-tree.txt b/Documentation/git-commit-tree.txt index 0fdb82ee..02133d5f 100644 --- a/Documentation/git-commit-tree.txt +++ b/Documentation/git-commit-tree.txt @@ -68,7 +68,9 @@ if set: In case (some of) these environment variables are not set, the information is taken from the configuration items user.name and user.email, or, if not -present, system user name and fully qualified hostname. +present, system user name and the hostname used for outgoing mail (taken +from `/etc/mailname` and falling back to the fully qualified hostname when +that file does not exist). A commit comment is read from stdin. If a changelog entry is not provided via "<" redirection, 'git commit-tree' will just wait @@ -90,6 +92,10 @@ Discussion include::i18n.txt[] +FILES +----- +/etc/mailname + SEE ALSO -------- linkgit:git-write-tree[1] diff --git a/ident.c b/ident.c index 35a6f264..edb43144 100644 --- a/ident.c +++ b/ident.c @@ -50,6 +50,54 @@ static void copy_gecos(const struct passwd *w, char *name, size_t sz) } +static int add_mailname_host(char *buf, size_t len) +{ + FILE *mailname; + + mailname = fopen("/etc/mailname", "r"); + if (!mailname) { + if (errno != ENOENT) + warning("cannot open /etc/mailname: %s", + strerror(errno)); + return -1; + } + if (!fgets(buf, len, mailname)) { + if (ferror(mailname)) + warning("cannot read /etc/mailname: %s", + strerror(errno)); + fclose(mailname); + return -1; + } + /* success! */ + fclose(mailname); + return 0; +} + +static void add_domainname(char *buf, size_t len) +{ + struct hostent *he; + size_t namelen; + const char *domainname; + + if (gethostname(buf, len)) { + warning("cannot get host name: %s", strerror(errno)); + strlcpy(buf, "(none)", len); + return; + } + namelen = strlen(buf); + if (memchr(buf, '.', namelen)) + return; + + he = gethostbyname(buf); + buf[namelen++] = '.'; + buf += namelen; + len -= namelen; + if (he && (domainname = strchr(he->h_name, '.'))) + strlcpy(buf, domainname + 1, len); + else + strlcpy(buf, "(none)", len); +} + static void copy_email(const struct passwd *pw) { /* @@ -61,20 +109,12 @@ static void copy_email(const struct passwd *pw) die("Your sysadmin must hate you!"); memcpy(git_default_email, pw->pw_name, len); git_default_email[len++] = '@'; - gethostname(git_default_email + len, sizeof(git_default_email) - len); - if (!strchr(git_default_email+len, '.')) { - struct hostent *he = gethostbyname(git_default_email + len); - char *domainname; - len = strlen(git_default_email); - git_default_email[len++] = '.'; - if (he && (domainname = strchr(he->h_name, '.'))) - strlcpy(git_default_email + len, domainname + 1, - sizeof(git_default_email) - len); - else - strlcpy(git_default_email + len, "(none)", - sizeof(git_default_email) - len); - } + if (!add_mailname_host(git_default_email + len, + sizeof(git_default_email) - len)) + return; /* read from "/etc/mailname" (Debian) */ + add_domainname(git_default_email + len, + sizeof(git_default_email) - len); } static void setup_ident(void)
-- 1.7.7.rc1