Enter the void

Latest 10 recent news (see index)

April 01, 2018

My Little Void

Because many ponies enjoyed the The Advent of Void: Day 25: ponysay post we decided to release a new Void Linux image with all your friends onboard.

Happy eastern to everypony!

December 25, 2017

The Advent of Void: Day 25: ponysay

Who of you ever wanted a pony for Christmas? Turns out, Void Linux already includes some. Don’t worry, they are just virtual yet just a command away:

# xbps-install ponysay

Screenshot of ponysay(1)

ponysay features over 400 illustrations of My Little Pony for your terminal. Look at all of them using

% ponysay-tool --browse /usr/share/ponysay/ponies

You even can make the ponies quote themselves using ponysay -q.

Lots of fun for everypony! Whee!

December 24, 2017

The Advent of Void: Day 24: snooze

cron(8) is a nice tool, but it has some long-standing problems, among them:

The cron/crond design requires setuid.
Making cronjobs not overlap requires additional work.
It’s not possible to trigger a cronjob to run now, instead of the next scheduled time.
The crontab syntax is confusing (if you think this is not true, do you know about %?).

A little, but flexible alternative is to use snooze(1), which essentially just waits for a particular time, and then executes a command. To get recurring jobs ala cron, we can use this together with our runit service supervision suite. If we wanted at(1) instead, we can just run snooze once.

The time for snooze is given using the options -d (for day), -m (for month), -w (for weekday), -D (for day of year), -W (for ISO week), and -H (for hour), -M (for minute), -S (for second). Each option of these can be comma-separated list of values, ranges (with -) or repetitions (with /). The default is daily at midnight, so if we wanted to run at the next full hour instead, we could run:

% snooze -n -H'*'
2017-12-24T17:00:00+0100 Sun  0d  0h 47m 33s
2017-12-24T18:00:00+0100 Sun  0d  1h 47m 33s
2017-12-24T19:00:00+0100 Sun  0d  2h 47m 33s
2017-12-24T20:00:00+0100 Sun  0d  3h 47m 33s
2017-12-24T21:00:00+0100 Sun  0d  4h 47m 33s

The -n option disables the actual execution and shows the next five matching times instead.

To run every 15 minutes, we’d use

% snooze -n -H'*' -M/15  
2017-12-24T16:15:00+0100 Sun  0d  0h  1m 31s
2017-12-24T16:30:00+0100 Sun  0d  0h 16m 31s
2017-12-24T16:45:00+0100 Sun  0d  0h 31m 31s
2017-12-24T17:00:00+0100 Sun  0d  0h 46m 31s
2017-12-24T17:15:00+0100 Sun  0d  1h  1m 31s

More complicated things are possible, for example next Friday the 13th:

% snooze -n -w5 -d13
2018-04-13T00:00:00+0200 Fri 108d  6h 45m 33s
2018-07-13T00:00:00+0200 Fri 199d  6h 45m 33s
no satisfying date found within a year.

Note that snooze bails out if it takes more than a year for the event to happen.

By default, snooze will just terminate successfully, but we can give it a command to run instead:

% snooze -H'*' -M'*' -S30 date 
Sun Dec 24 16:27:30 CET 2017

When snooze receives a SIGALRM, it immediately runs the command.

snooze is quite robust, it checks every 5 minutes the time has progressed as expected, so if you change the system time (or the timezone changes), it is noticed.

For additional robustness, you can use the timefiles option -t, which ensures a job is not started if its earlier than some modification time of a file. On success, your job can then touch this file to unlock the next iteration. Together with the slack option this can be used for anacron-style invocations that ensure a task is run, for example, every day at some point.

December 23, 2017

The Advent of Void: Day 23: ledger

Day 23, almost the end of the year. You may consider that it’s time to look back and take stock of your month, or your year. An accounting, if you will. Fortunately we have a package or two for that: ledger and hledger. The second one is a rewrite of the first in Haskell, while the first is the one that sets the spec.

I must apologize in advance: I am not an accountant, so I may confuse the powerful concepts on which accounting depends. Please bear with me, and feel free to let me know of any corrections.

These are accounting tools, with powerful features I never need to use, web interfaces I don’t need (but maybe others in our lives would desire), but are easy to use with text files with a simple format.

To pass a file to ledger (or hledger), just call ledger -f path/to/ledger.file, and make sure the file contains entries (or even just one) of the format:

2017-12-25	My true love gave to me
	Equity:TrueLove		-1 partridge
	Assets			1 partridge

The notion behind the ledger format is the same as double entry accounting. What goes in must come out, or everything must come from somewhere. If you take $5 from one place, it has to go somewhere else, in that same transaction.

2017-12-26	My true love gave to me and I paid back Tom
	Equity:TrueLove		-2 turtledove
	Assets			1 turtledove
	Assets:Tom		1 turtledove

For instance, the following ledger entry will throw an error because nothing matches!

2017-12-27	My true love gave to me
	Equity:TrueLove		-$3
	Assets			$1
	Assets:Tom		$1

(I switched to units where I could be certain the double entry mechanisms are checked. They don’t seem to be for french_hens.)

The ledger manual has a lot of information about all the things ledger supports, including inline maths and stock prices.

May your books forever be balanced!

December 22, 2017

The Advent of Void: Day 22: QDirStat

We already covered other cleaning tools like ncdu and probably everybody used some form of du -h ... | sort -h as well, but there is another little gem I’d like you to know about.

QDirStat - Qt-based directory statistics (KDirStat without any KDE - from the original KDirStat author)

QDirStat uses a treemap to display used disk space.

# xbps-install qdirstat

Files are represented as little boxes. The color hints the file type and the area covered corresponds to the file size. Then QDirStat tries to group files within a folder into one rectangle. This is done for the whole hierarchy. The per-folder cushion shading guides your eyes and makes it easy to recognise related files.

QDirStat screenshot with treemap

The treemap is interactive. To find what file belongs to a box, you can just click on it. With the Alt + ↑ shortcut, you can go one level up in the file hierarchy. At the same time a box is painted around the whole folder.

qdirstat-cache-writer - Collecting remote file statistics

With qdirstat-cache-writer (separate package, minimal dependencies) you can collect file sizes on remote or headless machines.

On the remote machine install the package and scan your disk with:

# xbps-install qdirstat-cache-writer
# qdirstat-cache-writer /path/of/interest cache-file.cache.gz

You can transfer the cache-file via ssh or any other method and just throw it against qdirstst locally:

# scp remote:/path/to/cace-file.cache.gz .
# qdirstat --cache cache-file.cache.gz

You can still examine the hierarchy, but you loose the ability to run the clean-up actions.

Extra bits

At the time of writing QDirStat had no open issues or pull requests. I’m not aware of any obvious bugs. It’s a unique and solid tool. My disks thank Stefan Hundhammer for his amazing work.

December 21, 2017

The Advent of Void: Day 21: neatvi

On Void, we have many clones of beloved vi(1) such as vim, neovim, nvi, vile, busybox vi, and of course the original ex-vi.

But today, I want to talk about neatvi, a reimplementation from scratch with minimal footprint (fewer than 6kLOC); it doesn’t even need ncurses! Nevertheless, it supports UTF-8, and even editing bidirectional text, and generally has a good coverage of the POSIX vi feature set.

Of course, it doesn’t provide all the bells and whistles of vim and friends, but it adds a few important features on top of plain vi, such as infinite undo/redo, basic syntax highlighting, and a partial implementation of ex(1).

It’s a nice editor for limited environments such as embedded devices or recovery systems, or for people that like unbloated software.

December 20, 2017

The Advent of Void: Day 20: shmux

When you have multiple machines, sometimes you’ll want to run the same commands on all of them. There are many tools for this job, starting from simple for loops on the shell to full-fledged configuration management systems such as Puppet or Chef.

A good compromise is shmux(1), the shell multiplexer.

For example, we can measure the uptimes of my servers, passing the command with -c:

% shmux -c uptime vuxu.org root@epona.vuxu.org hecate.home.vuxu.org
            vuxu.org:  15:48:01 up 91 days,  6:05, 45 users,  load average: 0.55, 0.47, 0.40
 root@epona.vuxu.org:  15:48:07 up 502 days, 19:29,  1 user,  load average: 0.37, 0.29, 0.29
hecate.home.vuxu.org:  15:48:03 up 225 days,  5:51,  2 users,  load average: 0.06, 0.03, 0.05

3 targets processed in 2 seconds.
Summary: 3 successes

shmux is quite clever about this, e.g. if we do a mistake and the command fails, it stops and asks us what to do:

shmux -c oopstime localhost vuxu.org root@epona.vuxu.org hecate.home.vuxu.org
           localhost! zsh:1: command not found: oopstime
               shmux! Child for localhost exited with status 127
-- [PAUSED], 3 Pending/0 Failed/1 Done -- [1.7, 1.8]
?
>> Available commands:
>>       q - Quit gracefully
>>       Q - Quit immediately
>> <space> - Pause (e.g. Do not spawn any more children)
>>       1 - Spawn one command, and pause if unsuccessful
>> <enter> - Keep spawning commands until one fails
>>       + - Always spawn more commands, even if some fail
>>       F - Toggle failure mode to "quit"
>>       S - Show current spawn strategy
>>       p - Show pending targets
>>       r - Show running targets
>>       f - Show failed targets
>>       e - Show targets with errors
>>       s - Show successful targets
>>       a - Show status of all targets
>>       k - Kill a target
a
>>  [0]             error: localhost
>>  [1]           pending: vuxu.org
>>  [2]           pending: root@epona.vuxu.org
>>  [3]           pending: hecate.home.vuxu.org
Q

1 target processed (out of 4) in 89 seconds.
Summary: 3 unprocessed, 1 error
Error    : localhost 

Commands can be spawned in parallel when using -M max. By default, shmux spawns the first command on its own, to check it early.

Let’s say we want to keep the outputs, so we use -o:

% shmux -M10 -o uptimes -c uptime localhost vuxu.org root@epona.vuxu.org hecate.home.vuxu.org
...
% ls uptimes 
 hecate.home.vuxu.org.exit    'root@epona.vuxu.org.exit'
 hecate.home.vuxu.org.stderr  'root@epona.vuxu.org.stderr'
 hecate.home.vuxu.org.stdout  'root@epona.vuxu.org.stdout'
 localhost.exit		       vuxu.org.exit
 localhost.stderr	       vuxu.org.stderr
 localhost.stdout	       vuxu.org.stdout

Finally, the -a and -A options can be used to define analyzers for the outputs, so see if everything worked fine.

% shmux -o uptimes -a regex -A up  -c uptime ...

shmux is a useful tool for adhoc command execution as it requires no configuration and has sensible defaults.

December 19, 2017

The Advent of Void: Day 19: mblaze part 2

Today is a followup on yesterdays mblaze(7) post.

This time I show how I use mblaze to send and receive patches using git and mblaze(7) as example.

First I create a patch file with git format-patch, afterwards I use mcom(1) to compose a new mail to that I deliver to my local mailbox for this example.

voidlinux.github.com@pi$ git format-patch HEAD~1
0001-The-Advent-of-Void-Day-18-mblaze-fixup.patch
voidlinux.github.com@pi$ mcom duncan@pi.lan
To: duncan@pi.lan
Cc:
Bcc:
Subject: [PATCH] mblaze advent fixup
Message-Id: <EWKLTW37CF.2MS3C7VXW22M0@pi.lan>
User-Agent: mblaze/0.2-56-g29d8946-dirty (2017-12-18)

Attachments can be added by starting a line with `#` following the
content type and the file name.

#text/plain 0001-The-Advent-of-Void-Day-18-mblaze-fixup.patch
"./snd.0" 11L, 332C written
What now? ([s]end, [c]ancel, [d]elete, [e]dit, [m]ime, sign, encrypt) m
./snd.0.mime
  1: multipart/mixed size=4342
    2: text/plain size=100
    3: text/plain size=3552 name="0001-The-Advent-of-Void-Day-18-mblaze-fixup.patch"
What now? ([s]end, [c]ancel, [d]elete, [e]dit, [m]ime, sign, encrypt) s

First mcom(1) opened my $EDITOR with a template mail, I added the subject, the body and my patch as attachment, using the #contenttype filename syntax. Then I write the file and close my editor (:wq), mcom(1) asks me then what to do next. I choose [m]ime first to attach the attachment, mime is requiered for mails that contain multiple parts. mcom(1) asks me again what to do next and I choose [s]end to deliver the mail.

On my system opensmtpd(8) delivers local mails to a maildir.

When the mail is delivered I use minc(1) to incorporate the new mails into maildirs cur directory and use mlist(1) and mseq(1) to create a new sequence to work with. With the new sequence I can now use mless(1) to read and navigate through my mails.

voidlinux.github.com@pi$ minc ~/mail/local -q
voidlinux.github.com@pi$ mlist ~/mail/local | mseq -S
voidlinux.github.com@pi$ mless
>.  1   Wed  01:30 duncan@pi.lan       [PATCH] mblaze advent fixup

From: <duncan@pi.lan>
Subject: [PATCH] mblaze advent fixup
To: duncan@pi.lan
Cc:
Date: Wed, 20 Dec 2017 01:30:05 +0100 (45 minutes, 6 seconds ago)

--- 1: multipart/mixed size=4342 ---
--- --- 2: text/plain size=100 charset="UTF-8" render="mflow -f" ---
Attachments can be added by starting a line with `#` following the
content type and the file name.

--- --- 3: text/plain size=3552 name="0001-The-Advent-of-Void-Day-18-mblaze-fixup.patch" render="mflow -f" ---
From 84eb8bea765561c2b4bb0b2b2d239393eb5c97f5 Mon Sep 17 00:00:00 2001
[...]

mless(1) saves the currently selected mail, which makes it possible to close mless(1) and then work with the last viewed mail using other mblaze(7) tools.

Because the mail contains a patch I want to apply I use mshow(1)s -t flag to get a list of the parts in the mail.

voidlinux.github.com@pi$ mshow -t
/home/duncan/mail/local/cur/1513729805.5186.pi.lan:2,
  1: multipart/mixed size=4342
    2: text/plain size=100
    3: text/plain size=3552 name="0001-The-Advent-of-Void-Day-18-mblaze-fixup.patch"

The third part is the patch file I attached earlier, mshow(1)s -O flag to extracts a specified part to stdout by its index or by using a pattern. I can just pipe the patch directly into git am to apply the patch and fix conflicts if necessary.

voidlinux.github.com@pi$ mshow -O . 3 | git am
Applying: The Advent of Void: Day 18: mblaze fixup

Now that the patch is applied and I flag the mail as seen and trashed using mflag(1), and update the sequence. Updating the sequence is necessary because the filename of the mail has changed, I use mseq(1)s -f flag in this example to just fix missing mails in the current sequence, using mlist(1) again like at the beginning would get the same result.

voidlinux.github.com@pi$ mflag -ST .
voidlinux.github.com@pi$ mseq -f | mseq -S

Using mscan(1) once again shows in the second column that the mail is marked as trashed.

voidlinux.github.com@pi$ mscan
>x  1   Wed  01:30 duncan@pi.lan       [PATCH] mblaze advent fixup
1 mails scanned

I hope this post gives a bit more insight on how to work with mblaze(7).

December 18, 2017

The Advent of Void: Day 18: mblaze

Today I want to introduce mblaze(7), a set of Unix utilities to deal with mails stored in the maildir format.

It aims to be used for both interactive usage and scripting, similar to MH or nmh. Except that its mblaze was written from scratch to be performant and memory efficient allowing to work with large amounts of mails. This results in a smaller and clean implementation which dropped support for (in our eyes) less useful features and improve usability.

The basic concept of mblaze is to work with sequences which are newline separated list of mail files with optional indention to represent threading. Sequences can be used in memory by using pipes or as files which enabled further features as explained later in this post.

There are tools to create, sort, filter and manipulate sequences, other tools like mshow, maddr or magrep use those sequences to gather, address or show specific mails from sequences.

mlist(1) creates the initial sequence, It takes mail directories as argument and prints out all the mails it can find, it also has some arguments to filter mails by flags that are stored in the file name, as example -S and -s to show only seen or not seen mails respectively.

$ mlist ~/mail/
/home/duncan/mail/1505313797.1422_503.tux,U=41583:2,S
/home/duncan/mail/1505402355.860_19.tux,U=41679:2,ST
/home/duncan/mail/1505402356.860_24.tux,U=41684:2,S
/home/duncan/mail/1505402355.860_23.tux,U=41683:2,S
/home/duncan/mail/1505402356.860_25.tux,U=41685:2,S
/home/duncan/mail/1505402355.860_22.tux,U=41682:2,
/home/duncan/mail/1505402355.860_20.tux,U=41680:2,S
/home/duncan/mail/1505402356.860_26.tux,U=41686:2,S
/home/duncan/mail/1505313797.1422_502.tux,U=41582:2,ST

Most mails and MUAs work with mails in threads, mblaze has mthread(1) to group the mails in a sequence into threads. To sort mails we use msort(1) which uses mail headers like Date or Subject to sort the sequence in the specified way.

$ mlist ~/mail/ | mthread
/home/duncan/mail//1505402355.860_19.tux,U=41679:2,ST
<voidlinux/void-packages/issues/7614@github.com>
 /home/duncan/mail//1505313797.1422_502.tux,U=41582:2,ST
 /home/duncan/mail//1505313797.1422_503.tux,U=41583:2,S
 /home/duncan/mail//1505402355.860_20.tux,U=41680:2,S
/home/duncan/mail//1505402355.860_22.tux,U=41682:2,
 /home/duncan/mail//1505402355.860_23.tux,U=41683:2,S
 /home/duncan/mail//1505402356.860_24.tux,U=41684:2,S
<voidlinux/void-packages/pull/7639@github.com>
 /home/duncan/mail//1505402356.860_25.tux,U=41685:2,S
 /home/duncan/mail//1505402356.860_26.tux,U=41686:2,S
9 mails threaded
$ mlist ~/mail/ | mthread | msort -d
<voidlinux/void-packages/issues/7614@github.com>
 /home/duncan/mail//1505313797.1422_502.tux,U=41582:2,ST
 /home/duncan/mail//1505313797.1422_503.tux,U=41583:2,S
 /home/duncan/mail//1505402355.860_20.tux,U=41680:2,S
 /home/duncan/mail//1505402355.860_23.tux,U=41683:2,S
 /home/duncan/mail//1505402356.860_24.tux,U=41684:2,S
<voidlinux/void-packages/pull/7639@github.com>
 /home/duncan/mail//1505402356.860_25.tux,U=41685:2,S
 /home/duncan/mail//1505402356.860_26.tux,U=41686:2,S
/home/duncan/mail//1505402355.860_19.tux,U=41679:2,ST
/home/duncan/mail//1505402355.860_22.tux,U=41682:2,
9 mails threaded

To avoid creating and piping sequences every time we can use mseq(1) to save and manipulate mail sequence files. If the sequence is stored as file the mblaze utilities can use the sequence from the file to address mails by index numbers and mmsg(7) selectors.

$ mlist ~/mail/ | mthread | msort -d  | mseq -S
9 mails threaded
$ cat ~/.mblaze/seq
<voidlinux/void-packages/issues/7614@github.com>
 /home/duncan/mail//1505313797.1422_502.tux,U=41582:2,ST
 /home/duncan/mail//1505313797.1422_503.tux,U=41583:2,S
 /home/duncan/mail//1505402355.860_20.tux,U=41680:2,S
 /home/duncan/mail//1505402355.860_23.tux,U=41683:2,S
 /home/duncan/mail//1505402356.860_24.tux,U=41684:2,S
<voidlinux/void-packages/pull/7639@github.com>
 /home/duncan/mail//1505402356.860_25.tux,U=41685:2,S
 /home/duncan/mail//1505402356.860_26.tux,U=41686:2,S
/home/duncan/mail//1505402355.860_19.tux,U=41679:2,ST
/home/duncan/mail//1505402355.860_22.tux,U=41682:2,

Now that the sequence is saved we can continue can use mscan(1) a tool to print one line message lists including the subject, the date and a visual representation for the flags.

$ mscan
                                       \_ <voidlinux/void-packages/issues/7614@github.com>
 x  2   Sun Sep 10 gravicappa            Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    3   Sun Sep 10 Lain                  Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    4   Thu Sep 14 Enno Boland           Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    5   Thu Sep 14 Dominic Monroe        Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
    6   Thu Sep 14 lemmi                 Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
                                       \_ <voidlinux/void-packages/pull/7639@github.com>
    8   Thu Sep 14 Michael Gehring       Re: [voidlinux/void-packages] libcaca: add (optional) support for imlib2 (#7639)
    9   Thu Sep 14 newbluemoon           Re: [voidlinux/void-packages] libcaca: add (implicit) support for imlib2 (#7639)
 x  10  Thu Sep 14 Michael Gehring     Re: [voidlinux/void-packages] libdockapp: Corrected incorrect entry in shlibs (#7652)
 .  11  Thu Sep 14 lemmi               [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
11 mails scanned

The first column is for flags, x is for Trashed mails, and . (dot) for unseen mails, the second column is the index of the mail in the sequence.

mscan can use the previously mentioned mmsg(7) syntax to address or select mails. In this example the first one just addresses two mails by their index, the second example selects a range of mails starting and ending at the specified index.

$ mscan 2 5
 x  2   Sun Sep 10 gravicappa            Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    5   Thu Sep 14 Dominic Monroe        Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
2 mails scanned
$ mscan 2:5
 x  2   Sun Sep 10 gravicappa            Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    3   Sun Sep 10 Lain                  Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    4   Thu Sep 14 Enno Boland           Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    5   Thu Sep 14 Dominic Monroe        Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
4 mails scanned

The next tool is mshow(1) which renders mails or extracts attachments.

$ mshow 2
From: gravicappa <notifications@github.com>
Subject: Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
To: voidlinux/void-packages <void-packages@noreply.github.com>
Cc: Duncan Overbruck <duncaen@voidlinux.eu>,  Comment <comment@noreply.github.com>
Date: Sun, 10 Sep 2017 09:30:36 -0700 (14 weeks, 1 day, 1 hour ago)
Reply-To: voidlinux/void-packages <reply+002aecdf7dfdc8d5ee7bc8a57eb08b436b6d3af844c59c4192cf0000000115cd2aac92a169ce0f49ca87@reply.github.com>

--- 1: multipart/alternative size=2477 ---
--- --- 2: text/plain size=258 charset="UTF-8" render="mflow -f" ---
It shows cyrillics correctly but inputting whose with keyboard yields nothing.

--
You are receiving this because you commented.
Reply to this email directly or view it on GitHub:
https://github.com/voidlinux/void-packages/issues/7614#issuecomment-328354106

mless(1) is a small wrapper around less that lets you page through your sequence. On the top it prints a few lines from mscan with the current mail highlighted and on the bottom it shows the content of the mail. You can now use :n and :p to navigate through mails.

$ mless
 x  3   Sun Sep 10 gravicappa            Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614
    4   Sun Sep 10 Lain                  Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614
>   5   Thu Sep 14 Enno Boland           Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614
 .  6   Thu Sep 14 lemmi               [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EU
    7   Thu Sep 14 Dominic Monroe        Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's
    8   Thu Sep 14 lemmi                 Re: [voidlinux/void-packages] Replace caddy with wedge in light of caddy's

From: Enno Boland <notifications@github.com>
Subject: Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
To: voidlinux/void-packages <void-packages@noreply.github.com>
Cc: Duncan Overbruck <duncaen@voidlinux.eu>,  Comment <comment@noreply.github.com>
Date: Wed, 13 Sep 2017 23:15:15 -0700 (13 weeks, 4 days, 17 hours ago)
Reply-To: voidlinux/void-packages <reply+002aecdfbf62a2c14f84705a7fd3c31678cfae556dcc03ee92cf0000000115d1e07392a169ce0f49ca87@reply.github.com>

--- 1: multipart/alternative size=2827 ---
--- --- 2: text/plain size=197 charset="UTF-8" render="mflow -f" ---
Closed #7614 via #7633.

--
You are receiving this because you commented.
Reply to this email directly or view it on GitHub:
https://github.com/voidlinux/void-packages/issues/7614#event-1248561716
~
~
mless 2 (message 3 of 12)

Another tool is mpick(1) which can be used to write extensive filters for mail sequences.

$ mpick -t 'subject =~~ "dmenu"' | mscan
 x  3   Sun Sep 10 gravicappa            Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
    4   Sun Sep 10 Lain                  Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
>   5   Thu Sep 14 Enno Boland           Re: [voidlinux/void-packages] dmenu-4.7 doesn't allow cyrillic input (#7614)
11 mails tested, 3 picked.
3 mails scanned

In the next example mpick only picks mails between two dates and tests if the replied flag is set or the seen flag is not set.

$ mpick -t 'date >= "2017-09-01" && date < "2017-10-01" && (replied || !seen)' | mscan
 .  6   Thu Sep 14 lemmi               [voidlinux/void-packages] Replace caddy with wedge in light of caddy's new EULA (#7657)
11 mails tested, 1 picked.
1 mails scanned

This is just a very small example, mblaze is capable of a lot more and has great man pages that are worth reading, see mblaze(7) and the git repository as starting point if you want to learn more about it.

December 17, 2017

The Advent of Void: Day 17: dstat

There are many ways to see what’s going on your system, such as top(1), htop(1), atop(1). However, these tools only show the current state of the system, and it’s not so easy to see how the data changes.

dstat(1) works differently: it prints a line every second with some system stats you can configure. By default, it shows CPU usage, disk I/O, network traffic, paging, and context switches:

% dstat
You did not select any stats, using -cdngy by default.
--total-cpu-usage-- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai stl| read  writ| recv  send|  in   out | int   csw 
 45   9  45   1   0| 284k  181k|   0     0 |  18k   36k| 754  2181 
 28   6  65   1   0|   0     0 |4698k  222k|   0     0 |4123    17k
 34   8  58   0   0|   0     0 |4730k  220k|   0     0 |5253    20k
 29   8  62   1   0|4096B 1080k|4640k  215k|   0     0 |4383    18k
 37   7  38  17   0|   0    15M|4844k  219k|   0     0 |5532    21k
 31   8  30  32   0| 336k 6840k|5153k  232k|   0     0 |4383    17k
...

For Void development, I like to run this configuration; showing per-core CPU usage, memory usage, process spawn rate and I/O.

% dstat --cpu-use -mpr
---------per-cpu-usage--------- ------memory-usage----- ---procs--- --io/total-
 1   2   3   4   5   6   7 | used  free  buff  cach|run blk new| read  writ
 2   1   1   1   1   1   1| 550M 2510M 2823M 1315M|  0   0 4.4|6.42  0.93 
 0   0   0   0   1   0   0| 550M 2510M 2823M 1315M|  0   0 1.0|   0     0 
 2   1   1   0   0   0   1| 551M 2508M 2823M 1315M|  0   0  20|   0     0 
 0   0   0   0   0   0   0| 551M 2508M 2823M 1315M|  0   0   0|   0     0 
 0   0   0   0   0   0   0| 551M 2509M 2823M 1315M|  0   0   0|   0     0 
 0   0   0   0   1   0   0| 551M 2509M 2823M 1315M|  0   0   0|   0     0 

This allows us to easily detect if builds are not optimally parallelized, or whether we run into memory limits. And process spawn rate detects if a ./configure script runs. ;)

dstat includes a huge list of probes it can display, just to list a few: battery usage, free disk, MySQL/InnoDB stats, qmail queue size, NFS traffic, NTP stats, WiFi measurements, ZFS information.

It’s a very versatile tool, and because it works via the console, you can also easily run it over SSH.