- http://elpa.gnu.org/ – GNU Emacs Lisp Package Archive
- http://melpa.org – Milkypostman’s Emacs Lisp Package Archive
- http://melpa.org/#/getting-started
I first came across MELPA through jira-markup-mode:
Blog
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Emacs Lisp Package Archives (ELPA)
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Travis CI
- https://en.wikipedia.org/wiki/Travis_CI
- https://travis-ci.org – free services
- https://travis-ci.com – payed services
A nice Travis CI sample project:
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getent – “get entries from administrative database”
The getent command displays entries from databases supported by the Name Service Switch libraries, which are configured in /etc/nsswitch.conf. If one or more key arguments are provided, then only the entries that match the supplied keys will be displayed. Otherwise, if no key is provided, all entries will be displayed (unless the database does not support enumeration).
My DS713+ (Intel based Synology NAS) does not have in on board, its Entware repository neither, but using “locate” I spotted a binary in a docker installation. It looks, like it is compiled for Debian, but it runs anyway.
- https://cygwin.com/packages/x86_64/getent/ – getent on cygwin
getent on macOS: basically it’s not there and there is no way to get it, and it does not make sense to emulate it; use the right tools on macOS!
- http://zzamboni.org/brt/2008/01/21/how-to-emulate-unix-getent-with-macosxs-dscl/
- https://apple.stackexchange.com/questions/44567/how-can-i-install-getent-on-snow-leopard
- https://unix.stackexchange.com/questions/373309/mac-os-command-to-resolve-hostnames-like-getent-on-linux
- https://superuser.com/questions/279891/list-all-members-of-a-group-mac-os-x/395738
- https://www.cyberciti.biz/faq/check-list-users-unix/
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comparing /proc/12345/cmdline on Linux — “diff –text” vs “diff –brief –text” vs “cmp –silent”
A cmdline “file” contains NUL characters, so “
diff” needs to be used with “--text” otherwise it will fail anyway.I chose process ID 12345 deliberately, it is just a placeholder.
$ cp /proc/12345/cmdline $HOME/cmdline $ ll /proc/12345/cmdline ~/cmdline -r--r--r-- 1 root root 0 2018-06-12 09:22:50 /proc/12345/cmdline -r--r--r-- 1 user users 45 2018-06-12 09:48:19 /homes/user/cmdline # /proc/12345/cmdline is a file in the proc filesystem. # is the displayed size a bug or a feature? $ wc --bytes /proc/12345/cmdline ~/cmdline 45 /proc/12345/cmdline 45 /homes/user/cmdline 90 total $ diff --text /proc/12345/cmdline ~/cmdline; echo $? 0 # as we expect $ diff --brief /proc/12345/cmdline ~/cmdline; echo $? Files /proc/12345/cmdline and /homes/user/cmdline differ 1 # why are they now different? $ cmp --silent /proc/12345/cmdline ~/cmdline; echo $? 1 # why are they now different?
“
diff --brief --text” and “cmp --silent” presumably take the file size into account.On Cygwin “
diff --brief --text” behaves like “diff --text“.I was quite surprised to experience these differences. It took me quite a while to realise, where my surprising processing results came from.
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dpk-query: why are certain packages being shown as “un … (no description available)”?
Solution: Some other package depends on this package, but only optionally resp. as an alternative; of the alternatives … one is indeed installed, but not this one, but still this is gets listed.
This is how the package first showed up:
$ dpkg-query --list foo... Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/... |/ Err?=(none)/... ||/ Name Version Architecture Description +++-======================-================-================-... un foo___________________ <none> <none> (no description available)I have that package “foo…” being displayed as Unknown (Desired) and Not (Status).
I am rather keen to know, why it gets listed at all.
I cannot find the right dpkg* command to tell me, which package depends on foo… .
This is sort of a “raw command” to help me:
$ fgrep --before 10 foo... /var/lib/dpkg/status
Update 2018-05-30:
This command line (almost) does, what I expect:
$ apt-rdepends --reverse foo... # the "r" in "rdepends" stands for "recursive"
The quirk is, that the dependency in fact is only optional resp. alternative (this is the reason, why the package is not installed), but this fact does not get displayed.
This command line does not, what I expect:
$ apt-cache rdepends foo... # the "r" in "rdepends" stands for "reverse"