Breve storia triste

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C'era una volta
Piero se volta
Casca 'na sopa
Piero se copa

La storia infinita (traumi infantili)

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Questa ze à storia
de sior Intento
che dura tanto tempo
che mai la sé destrìga
vuto che te à conta
o che te à diga?

https://youtu.be/Ir-9fjqShH8

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# create the filesystem
mkfs.extX -v    \ # verbose
  -j            \ # explicitly create the filesystem with an ext3 journal
  -b 4096       \ # block size (see /sys/block/sdXY/queue/physical_block_size)
  -E nodiscard  \ # do not TRIM encrypted SSD (ext4 only)
  -L nice_label \ # set a volume label
  /dev/sdXY

# tune options
tune2fs           \
  -c 60           \ # check filesystem every 60 mounts
  -C 0            \ # set current mount count
  -i 2m           \ # check filesystem every 2 months
  -e remount-ro   \ # on error remount filesystem read-only
  -m 3            \ # reserve 3% of space to root/defrag
  -o journal_data \ # all data committed into journal before writing to disk
  /dev/sdXY

Notes:

• remove line comments as they are not syntactically correct
• reserved space for defragmentation is useless for SSD: set 0% for data partitions and a number greater than 0 for system ones.
• if you use ext4 then read the post why Delayed Allocation is Bad and mount your partition with -o nodelalloc to make it safe against a server crash.
• on the raspberry pi avoid mounting a partition with journal_data option because in some circumstances it may lead to untolerable abysmal performance

Proc and lambda

Both types are anonymous functions and a lambda is just a special instance of Proc, their differences are:

• Lambdas are defined with ->() {} or lambda() {} and procs with Proc.new {} or proc{}
• Procs return from the current method (as they become part of the caller method), while lambdas return from the lambda itself (like calling a different method).
• Procs do not care about the correct number of arguments, while lambdas will raise an exception.

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l = -> { puts 'this is a lambda' }
l.class   # Proc
l.lambda? # true
l.call    # "this is a lambda"

l = ->(n) { n * 2 } # lambda with arguments
l.call 3    # 6
l.call 3, 4 # ArgumentError: wrong number of arguments

Pay attention at the different return behaviour:

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l = -> { return 1 }
p = Proc.new { return 1}

puts l.call
# 1

puts p.call # we cannot call return from the top-level context:
# LocalJumpError: unexpected return

def foo
  p = proc{ return 1}
  puts 'before'
  puts p.call # we can call return from a non top-level context
  puts 'after'
end

foo
# before
# 1

block

A block is an instance of Proc passed as a parameter to a method.

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def implicit_block
  yield 1, 2, 3 if block_given? # execute block if passed
end

def explicit_block(&block)
  block.call 1, 2, 3 if block_given? # execute block if passed
  implicit_block &block # you can pass the block to another method
end

implicit_block{|p1, p2, p3| puts p1+p2+p3 } # prints 6
explicit_block{|p1, p2, p3| puts p1+p2+p3 } # prints 6 two times

Source: blackbytes, sitepoint closures

My current ~/.config/xfce4/terminal/terminalrc:

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[Configuration]
BackgroundDarkness=0.900000
BackgroundMode=TERMINAL_BACKGROUND_TRANSPARENT
CommandLoginShell=TRUE
FontName=Monospace 10
MiscAlwaysShowTabs=FALSE
MiscBell=FALSE
MiscBellUrgent=FALSE
MiscBordersDefault=TRUE
MiscConfirmClose=TRUE
MiscCopyOnSelect=TRUE
MiscCursorBlinks=FALSE
MiscCursorShape=TERMINAL_CURSOR_SHAPE_BLOCK
MiscCycleTabs=TRUE
MiscDefaultGeometry=80x24
MiscDefaultWorkingDir=
MiscHighlightUrls=TRUE
MiscInheritGeometry=FALSE
MiscMenubarDefault=FALSE
MiscMiddleClickOpensUri=FALSE
MiscMouseAutohide=FALSE
MiscMouseWheelZoom=TRUE
MiscRewrapOnResize=TRUE
MiscSlimTabs=TRUE
MiscTabCloseButtons=TRUE
MiscTabCloseMiddleClick=TRUE
MiscTabPosition=GTK_POS_TOP
MiscToolbarDefault=FALSE
MiscUseShiftArrowsToScroll=TRUE
ScrollingLines=100000
ScrollingOnOutput=FALSE
ShortcutsNoMenukey=TRUE
ShortcutsNoMnemonics=TRUE
TitleInitial=shell
TitleMode=TERMINAL_TITLE_HIDE

and all available preferences as of version 0.8.6: