s-leroux/.gitignore

## .gitignore
tweet.*.txt
tweet.*.yaml
xx*
EXAMPLE-*

## commands
#! INIT
PS1="sh$ "
rm -f tweet.*.yaml
rm -f tweet.*.txt
rm -f tweet.???
rm -f xx??
echo BEGIN

#! POST
sed -E -e '1,/^BEGIN$/d' -e '/^sh\$ exit$/d' -e 's/^sh\$[ \t]*$//'

#= EXAMPLE-0
awk < tweets.yaml '
    /----/ { OUTPUT="tweet." (N++) ".yaml" }
    { print > OUTPUT }
'

ls -l tweet.*.yaml

#= EXAMPLE-1
# tag::A[]
csplit tweets.yaml /----/
#end::A[]

# tag::B[]
ls -l xx0*
#end::B[]
#= EXAMPLE-2
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    /----/

ls -l tweet.*


#= EXAMPLE-3
rm tweet.*
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/

ls -l tweet.*

#= EXAMPLE-4
# tag::A[]
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/ /----/ /----/
# end::A[]
# tag::B[]
ls -l tweet.???.yaml
# end::B[]

#= EXAMPLE-5
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/ '{*}'

#= EXAMPLE-6A
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/ '{6}'

#= EXAMPLE-7A
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/ '{999}'

ls tweet.*

#= EXAMPLE-7B
touch tweet.002.yaml
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    /----/ '{999}'

ls tweet.*

#= EXAMPLE-8A
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    /----/ '{999}'

ls tweet.*

#= EXAMPLE-8B
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    /----/ '{999}'
# tag::A[]
diff -s tweets.yaml <(cat tweet.*)
# end::A[]

#= EXAMPLE-9A
csplit tweets.txt \
    --prefix='tweet.' --suffix-format='%03d.txt' \
    --elide-empty-files \
    --keep-files \
    2 '{*}'

#= EXAMPLE-9B
csplit tweets.txt \
    --prefix='tweet.' --suffix-format='%03d.txt' \
    --elide-empty-files \
    --keep-files \
    2 '{*}'

# tag::A[]
diff -s tweets.txt <(cat tweet.*.txt)
# end::A[]

#= EXAMPLE-10A
csplit tweets.txt --keep-files 2 2 2 2 2

#= EXAMPLE-10B
csplit tweets.txt --keep-files 2 4 6 8 10

#= EXAMPLE-10C
csplit tweets.txt --keep-files 2 '{4}'

#= EXAMPLE-11
tr [:lower:] [:upper:] < tweets.txt | csplit - \
    --prefix='tweet.' --suffix-format='%03d.txt' \
    --elide-empty-files \
    --keep-files \
    2 '{3}'

head tweet.???.txt

#= EXAMPLE-12C
# Keep only the third and fourth tweets
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    %----% '{2}' /----/ '{2}' %----% '{*}'

head tweet.00[012].yaml

#= EXAMPLE-12B
# Skip the first two tweets
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    %----% '{2}' /----/ '{2}'

head tweet.00[012].yaml

#= EXAMPLE-12A
# Keep only the first two tweets
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    /----/ '{2}' %----% '{*}'

head tweet.00[012].yaml

#= EXAMPLE-13A
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    %----%+1 '{2}' /----/+1 '{2}' %----% '{*}'

head tweet.00[012].yaml

#= EXAMPLE-13B
csplit tweets.yaml \
    --prefix='tweet.' --suffix-format='%03d.yaml' \
    --elide-empty-files \
    --keep-files \
    %----%+1 '{2}' /----/+1 '{2}' %----% '{*}'

head tweet.00[012].yaml


## convert.awk
#!/usr/bin/awk -f

function flush() {
    if (status) {
        print "{" repeat "}"
        print status
    }

    reset();
}

function reset() {
    instatus = 0;
    repeat = "";
    status = "";
}

BEGIN {
    reset();
}

/----/ { flush(); next }
/repeat:/ { repeat = " " $3 $4 " "; next }
/status:/ { instatus = 1; next }

instatus {
    if (status)
        status = status "\\n";

    text = $0
    gsub(/^[ \t]+/, "", text)
    status = status text
}


END { flush() }

## run
#!/usr/bin/awk -f


function send(text) {
    if (!DIRTY) {
        gsub(/^[ \t\n]+/,"", text);
    }
    gsub(/[ \t\n]$/,"", text);

    if (text) {
        COMMAND = "bash -i 2>&1";

        gsub(/[\n]+$/, "", POST);
        if (!POST)
            POST = "cat"

        COMMAND = COMMAND " | " POST " > " OUTFILE;

        print text | COMMAND;

        DIRTY=1;
    }
}

function setOutFile(file) {
    if(DIRTY) close(COMMAND);

    DIRTY=0;
    OUTFILE = file;
}

BEGIN {
    OUTFILE = "example"

    STATES["INIT"] = ++_ID;
    STATES["WORK"] = ++_ID;
    STATES["POST"] = ++_ID;
}

/^#=/ {
    STATE = STATES["WORK"];
    BUFFER = "";
    FILE = $1 $2;
    gsub(/^#=[ \t]*/, "", FILE);
    setOutFile(FILE);
    send(INIT);
    DIRTY = 0;
    next;
}

/^#![ \t]*INIT/ {
    STATE = STATES["INIT"];
    next
}

/^#![ \t]*POST/ {
    STATE = STATES["POST"];
    next
}

STATE == STATES["INIT"] {
    INIT = INIT $0 "\n"
}

STATE == STATES["POST"] {
    POST = POST $0 "\n"
}

STATE == STATES["WORK"] {
    BUFFER = BUFFER $0 "\n"
}

STATE == STATES["WORK"] && /[^ \t]/ {
    send(BUFFER);
    BUFFER = "";
}

## tweets.txt
{ days:180 }
Still hesitating between #Vim and #Emacs?\nWhy not take a look at #spacemacs?\n\nhttp://spacemacs.org/
{}
Print the first column of a space-separated data file:\nawk '{print $1}' data.txt # Print out just the first column\n\nFor some unknown reason, I find that easier to remember than:\ncut -f1 data.txt\n\n#Linux #AWK #Cut
{}
For the #shell #beginners :\n« #GlobPatterns : how to move hundreds of files in not time [1/3] »\nhttps://youtu.be/TvW8DiEmTcQ\n\n#Unix #Linux\n#YesIKnowIT
{}
Want to know the oldest file in your disk?\n\nfind / -type f -printf '%TFT%.8TT %p\n' | sort | less\n(should work on any Single UNIX Specification compliant system)\n#UNIX #Linux
{}
When using the find command, use `-iname` instead of `-name` for case-insensitive search\n#Unix #Linux #Shell #Find
{}
From a POSIX shell `$OLDPWD` holds the name of the previous working directory:\ncd /tmp\necho You are here: $PWD\necho You were here: $OLDPWD\ncd $OLDPWD\n\n#Unix #Linux #Shell #cd
{}
From a POSIX shell, "cd" is a shorthand for cd $HOME\n#Unix #Linux #Shell #cd
{}
How to move hundreds of files in no time?\nUsing the find command!\n\nhttps://youtu.be/zmEFXjyzaQk\n#Unix #Linux #Move #Files #Find\n#YesIKnowIT
{}
If your shell supports history, use "!-1" to repeat the last command.\n"!!" is a shorthand for that too\n#Unix #Linux #Shell
{}
If your shell supports job control, type <CTRL-z> "bg" from its parent shell to send a process to the background\n#Shell #Bash #JobControl
{}
`ls -lt` will show files ordered by modification date — most recent first.\n\n#ls #shell #linux
{}
`ls -r` will reverse the normal order of the ls output. Try `ls -rlt` for example.\n\n#ls #shell #linux
{}
In the Bash, pressing "ctrl-x ctrl-v" will display its version informations.\n\n#bash #linux
{}
You know the "globstar" feature of your Bash ?\nLet's talk about that !\nhttps://youtu.be/N8zAA7GG56g\n\n#Linux #Bash #Globstar
{}
20 files to rename. 5 seconds per file. 1"40 of boring work?\nNo: 15 seconds if you know the right command\nhttps://yesik.it/EP04\n\n#Shell #Rename #PRename
{}
`less -R` will handle gracefully ANSI "color" escape sequences:\nls --color=always /tmp | less -R\n\n#Linux #Shell #ls
{}
`‥ | read ‥` is not portable between #zsh and #bash\n\nCompare in both shells :\necho 1 | read X; echo $X
{}
In Bash the pseudo-variable RANDOM returns a pseudo-random integer in the [0;32767] range\n\necho $RANDOM\n\n#Bash #Random
{}
With Bash history, `^str1^str2^` will repeat the previous command replacing `str1` by `str2`\n\necho 1223\n^2^4^\n\n#Bash
{ days:200 }
Nice introductory article on Awk by Justin Ellingwood (@jmellingwood):\nhttps://www.digitalocean.com/community/tutorials/how-to-use-the-awk-language-to-manipulate-text-in-linux
{}
If you don't know what is #Awk or how it could help you processing text files, then you NEED that little introduction:\nhttps://youtu.be/PUYS6MO4p7Y\n\n#Linux #Shell #AWK\n#YesIKnowIT
{}
In Bash `$(<file)` is equivalent to `$(cat file)`, but faster:\n\nP=( $(</etc/passwd) )\necho ${P[0]}\n\n#Bash #Linux #Cat
{}
The #Bash has the notion of "integer" variable:\n\ndeclare A=1; declare -i B=2\nA+=3; B+=4\necho $A $B\n⇒ 13 6\n\n#Shell
{}
In Bash,\n`~+` is expanded to the content of `PWD`\n`~-` is expanded to the content of `OLDPWD`\n\ncd /tmp\necho You are here: ~+\necho You were here: ~-\n\n#Bash #Shell
{ days:65 }
Do you know I have a "Bash and Linux Command Line" course On #Udemy?\nTake a look here for a discount:\nhttps://yesik.it/BSH101
{}
In #Bash, to edit the last three commands in your favorite EDITOR type:\n\nfc -3 0\n\nWhen leaving the editor, commands are executed
{}
To leave #vim with a non-zero exit code use `:cq`.\n\nUseful to abort a #Git commit or a #Bash `fc` command
{}
So, you don't know yet the `grep` command ?\nhttps://youtu.be/HBNNO92Juw4\n\n#Shell #Linux #Grep\n#YesIKnowIT
{ days:180 }
Nice introduction to sed, the Stream EDitor :\n\nhttps://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux\nby @jmellingwood
{}
Not all you can do with sed, but a cool reminder for the most basic use cases:\nhttps://www.yesik.it/SEDCS1\n\n#sed #cheatsheet
{}
I think I use the `sed` command daily. And you?\n\nhttps://www.yesik.it/EP07\n#Shell #Linux #Sed\n#YesIKnowIT
{}
Delete the last line of a file:\nsed '$d' file\n\n#Shell #Sed #Linux
{}
Delete all but the last line of a file:\nsed -n '$p' file\n\n#Shell #Sed #Linux
{}
Display the first 5 lines of a file:\nsed '5q' file\n\n#Shell #Sed #Linux
{}
Hello,\nI'm Sylvain...\n... and I'm a Vim Addict.\n\nhttps://itsfoss.com/pro-vim-tips/  by @Yes_I_Know_IT\n#Vim #TextEditor #Linux\n#YesIKnowIT
{}
Centering text on 80 columns with stars:\nsed -E ':x\ns/^.{,80}$/*&/\ns/^.{,80}$/&*/\ntx\n' file\n\n#Shell #Sed #Linux
{}
Right-align text on 80 columns:\nsed -E ':a /.{80}/!{s/^/ /;ba}' file\n\n#Shell #Sed #Linux
{}
The sed substitution (s) command is by far the most useful. But did you know ALL these patterns:\nhttps://www.yesik.it/EP08\n\n#Linux #Sed\n#YesIKnowIT
{}
ddrescue is one of the best tools to recover damaged disk (HD or optical).\n/!\ Don't miss the "log" feature for multipass recovery!\nhttps://www.linux.com/learn/intro-to-linux/2017/3/gnu-ddrescue-best-damaged-drive-rescue\n\n#HD #DVD #Rescue #RIP #ddrescue #Linux
{}
In a #sed substitution pattern, you can use any character as a separator instead of /\nUseful for path or urls:\ns!/usr/local!/opt!\n\n#Linux #UNIX
{}
Put emphasis around the Beattles\nsed -E 's!(John|Paul|George|Ringo)!<em>&</em>!g' file\n\n#Sed #Linux\nfrom https://www.yesik.it/EP08
{}
Looking for an explanation of what is the kernel and how it relates to userspace applications?\nTake a look at that video:\nhttps://yesik.it/EP09\n\n#Kernel #Linux\n#YesIKnowIT
{}
GNU sed has a nice 'e' modifier for substitutions:\nsed 's/.*/date +%F -d &/e' << EOT\nnow\ntomorrow\nyesterday\nEOT\n\n#GNU #sed #Linux
{ days:180 }
Bash scripting 101:\nhttps://jvns.ca/blog/2017/03/26/bash-quirks/\nby @b0rk
{}
I investigate Diaspora* as an alternate social network.\nAnyone there?\nhttps://diasp.eu/public/YesIKnowIT\n#Diaspora @joindiaspora\n#YesIKnowIT
{ days:180 }
#Vim is great.\nI like #tmux more and more.\n\nHow could it be to use them both at the same time?\nhttps://blog.bugsnag.com/tmux-and-vim/\nby @keeganlow
{}
A #Mastodon instance for #Linux Lovers\nhttps://linuxrocks.online/about\n\nTry that new #SocialNetwork and follow me there https://yesik.it/mastodon\n#YesIKnowIT
{}
"I want to learn Linux. Is Kali right for me?"\nYes? No? Is that so simple?\n\nhttps://itsfoss.com/kali-linux-review/\n\n#Linux #Kali @itsfoss2\n#YesIKnowIT
{}
Glob patterns, from the basics to subtle corner cases:\nhttps://www.yesik.it/EP11\n\n#Linux #Shell #Bash #GlobPattern\n#YesIKnowIT
{ days:180 }
Very great description of the difference between VMs and Containers\nby @mikegcoleman\nhttps://blog.docker.com/2016/03/containers-are-not-vms/\n\n#Docker #Containers
{}
What is #Virtualization?\nAnd how does that relate to #Emulation, #Containers and #CloudComputing?\n\nhttps://www.yesik.it/EP12\n#YesIKnowIT
{ days:180 }
Different does not mean better or worst. It just means different.\n\nhttps://www.linux.com/learn/intro-to-linux/2017/6/what-nosql\nby @CarlaSchroder\n\n#SQL #NoSQL
{}
#VM #Containers #Emulation #Wine?\nWhich virtualization technology is the best for YOUR needs?\n\nhttps://yesik.it/VIRT101\n\n#CheatSheet\n#YesIKnowIT
{}
Print odd lines\nseq 10 | sed -n 'P;N'\n\n#Shell #Sed #Linux
{}
Print even lines\nseq 10 | sed -n '1b;P;N'\n\n#Shell #Sed #Linux
{}
My #Bash book available both as #PaperBook and #eBook\n\nhttps://yesik.it/BASH-IT-OUT/PAPER\nhttps://yesik.it/BASH-IT-OUT/PDF\nhttps://yesik.it/BASH-IT-OUT\n@itsfoss2\n#Linux #Shell #Puzzle #Book\n#YesIKnowIT
{ days:180 }
split and csplit -- old friends, I used a lot in the 1.44MB floppy disk era...\n\nhttps://www.linux.com/learn/intro-to-linux/2017/8/splitting-and-re-assembling-files-linux\nby @CarlaSchroder\n\n#Linux #Unix #Split #csplit
{}
In AWK an action without associated pattern defaults to 1.\nSo those two commands are the same:\n\nseq 10 | awk '{print}'\nseq 10 | awk '1 {print}'\n\n#Shell #AWK
{}
In AWK a pattern without associated action defaults to '{ print }':\nSo those two commands are the same:\n\nseq 10 | awk /1/ is the same as\nseq 10 | awk '/1/ {print}'\n\n#Shell #AWK
{}
Three completly different AWK programs:\n\nseq 10 | awk '1 { print }'\nseq 10 | awk '/1/ { print }'\nseq 10 | awk 'NR==1 { print }'\n\n#Shell #AWK #regex
{}
#OpenStack is a complex and somewhat frightening beast\nhttps://opensource.com/resources/what-is-openstack
{}
If you ever had to connect to an Oracle backend, you may know how painful it used to be to set up an Oracle Instance on your test/dev host.\n\nThanks to @Docker, it is now several orders of magnitude simpler!\n\nhttps://yesik.it/EP18\n\n#Oracle #Database\n#Docker #Container\n#Linux
{}
Fine tune Linux Kernel I/O by setting up dirty page parameters.\n\nhttps://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/\n\n#Linux #Kernel #Cache #Disk #Tuning

## tweets.yaml
----
  event:
    repeat: { days: 180 }
  status: |
    Still hesitating between #Vim and #Emacs?
    Why not take a look at #spacemacs?

    http://spacemacs.org/
----
  status: |
    Print the first column of a space-separated data file:
    awk '{print $1}' data.txt # Print out just the first column

    For some unknown reason, I find that easier to remember than:
    cut -f1 data.txt

    #Linux #AWK #Cut
----
  status: |
    For the #shell #beginners :
    « #GlobPatterns : how to move hundreds of files in not time [1/3] »
    https://youtu.be/TvW8DiEmTcQ

    #Unix #Linux
    #YesIKnowIT
----
  status: |
    Want to know the oldest file in your disk?

    find / -type f -printf '%TFT%.8TT %p\n' | sort | less
    (should work on any Single UNIX Specification compliant system)
    #UNIX #Linux
----
  status: |
    When using the find command, use `-iname` instead of `-name` for case-insensitive search
    #Unix #Linux #Shell #Find
----
  status: |
    From a POSIX shell `$OLDPWD` holds the name of the previous working directory:
    cd /tmp
    echo You are here: $PWD
    echo You were here: $OLDPWD
    cd $OLDPWD

    #Unix #Linux #Shell #cd
----
  status: |
    From a POSIX shell, "cd" is a shorthand for cd $HOME
    #Unix #Linux #Shell #cd
----
  status: |
    How to move hundreds of files in no time?
    Using the find command!

    https://youtu.be/zmEFXjyzaQk
    #Unix #Linux #Move #Files #Find
    #YesIKnowIT
----
  status: |
    If your shell supports history, use "!-1" to repeat the last command.
    "!!" is a shorthand for that too
    #Unix #Linux #Shell
----
  status: |
    If your shell supports job control, type <CTRL-z> "bg" from its parent shell to send a process to the background
    #Shell #Bash #JobControl
----
  status: |
    `ls -lt` will show files ordered by modification date — most recent first.

    #ls #shell #linux
----
  status: |
    `ls -r` will reverse the normal order of the ls output. Try `ls -rlt` for example.

    #ls #shell #linux
----
  status: |
    In the Bash, pressing "ctrl-x ctrl-v" will display its version informations.

    #bash #linux
----
  status: |
    You know the "globstar" feature of your Bash ?
    Let's talk about that !
    https://youtu.be/N8zAA7GG56g

    #Linux #Bash #Globstar
----
  status: |
    20 files to rename. 5 seconds per file. 1"40 of boring work?
    No: 15 seconds if you know the right command
    https://yesik.it/EP04

    #Shell #Rename #PRename
----
  status: |
    `less -R` will handle gracefully ANSI "color" escape sequences:
    ls --color=always /tmp | less -R

    #Linux #Shell #ls
----
  status: |
    `‥ | read ‥` is not portable between #zsh and #bash

    Compare in both shells :
    echo 1 | read X; echo $X
----
  status: |
    In Bash the pseudo-variable RANDOM returns a pseudo-random integer in the [0;32767] range

    echo $RANDOM

    #Bash #Random
----
  status: |
    With Bash history, `^str1^str2^` will repeat the previous command replacing `str1` by `str2`

    echo 1223
    ^2^4^

    #Bash
----
  event:
    repeat: { days: 200 }
  status: |
    Nice introductory article on Awk by Justin Ellingwood (@jmellingwood):
    https://www.digitalocean.com/community/tutorials/how-to-use-the-awk-language-to-manipulate-text-in-linux
----
  status: |
    If you don't know what is #Awk or how it could help you processing text files, then you NEED that little introduction:
    https://youtu.be/PUYS6MO4p7Y

    #Linux #Shell #AWK
    #YesIKnowIT
----
  status: |
    In Bash `$(<file)` is equivalent to `$(cat file)`, but faster:

    P=( $(</etc/passwd) )
    echo ${P[0]}

    #Bash #Linux #Cat
----
  status: |
    The #Bash has the notion of "integer" variable:

    declare A=1; declare -i B=2
    A+=3; B+=4
    echo $A $B
    ⇒ 13 6

    #Shell
----
  status: |
    In Bash,
    `~+` is expanded to the content of `PWD`
    `~-` is expanded to the content of `OLDPWD`

    cd /tmp
    echo You are here: ~+
    echo You were here: ~-

    #Bash #Shell
----
  event:
    repeat: { days: 65 }
  status: |
    Do you know I have a "Bash and Linux Command Line" course On #Udemy?
    Take a look here for a discount:
    https://yesik.it/BSH101
----
  status: |
    In #Bash, to edit the last three commands in your favorite EDITOR type:

    fc -3 0

    When leaving the editor, commands are executed
----
  status: |
    To leave #vim with a non-zero exit code use `:cq`.

    Useful to abort a #Git commit or a #Bash `fc` command
----
  status: |
    So, you don't know yet the `grep` command ?
    https://youtu.be/HBNNO92Juw4

    #Shell #Linux #Grep
    #YesIKnowIT
----
  event:
    repeat: { days: 180 }
  status: |
    Nice introduction to sed, the Stream EDitor :

    https://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux
    by @jmellingwood
----
  status: |
    Not all you can do with sed, but a cool reminder for the most basic use cases:
    https://www.yesik.it/SEDCS1

    #sed #cheatsheet
----
  status: |
    I think I use the `sed` command daily. And you?

    https://www.yesik.it/EP07
    #Shell #Linux #Sed
    #YesIKnowIT
----
  status: |
    Delete the last line of a file:
    sed '$d' file

    #Shell #Sed #Linux
----
  status: |
    Delete all but the last line of a file:
    sed -n '$p' file

    #Shell #Sed #Linux
----
  status: |
    Display the first 5 lines of a file:
    sed '5q' file

    #Shell #Sed #Linux
----
  status: |
    Hello,
    I'm Sylvain...
    ... and I'm a Vim Addict.

    https://itsfoss.com/pro-vim-tips/  by @Yes_I_Know_IT
    #Vim #TextEditor #Linux
    #YesIKnowIT
----
  status: |
    Centering text on 80 columns with stars:
    sed -E ':x
    s/^.{,80}$/*&/
    s/^.{,80}$/&*/
    tx
    ' file

    #Shell #Sed #Linux
----
  status: |
    Right-align text on 80 columns:
    sed -E ':a /.{80}/!{s/^/ /;ba}' file

    #Shell #Sed #Linux
----
  status: |
    The sed substitution (s) command is by far the most useful. But did you know ALL these patterns:
    https://www.yesik.it/EP08

    #Linux #Sed
    #YesIKnowIT
----
  status: |
    ddrescue is one of the best tools to recover damaged disk (HD or optical).
    /!\ Don't miss the "log" feature for multipass recovery!
    https://www.linux.com/learn/intro-to-linux/2017/3/gnu-ddrescue-best-damaged-drive-rescue

    #HD #DVD #Rescue #RIP #ddrescue #Linux
----
  status: |
    In a #sed substitution pattern, you can use any character as a separator instead of /
    Useful for path or urls:
    s!/usr/local!/opt!

    #Linux #UNIX
----
  status: |
    Put emphasis around the Beattles
    sed -E 's!(John|Paul|George|Ringo)!<em>&</em>!g' file

    #Sed #Linux
    from https://www.yesik.it/EP08
----
  status: |
    Looking for an explanation of what is the kernel and how it relates to userspace applications?
    Take a look at that video:
    https://yesik.it/EP09

    #Kernel #Linux
    #YesIKnowIT
----
  status: |
    GNU sed has a nice 'e' modifier for substitutions:
    sed 's/.*/date +%F -d &/e' << EOT
    now
    tomorrow
    yesterday
    EOT

    #GNU #sed #Linux
----
  event:
    repeat: { days: 180 }
  status: |
    Bash scripting 101:
    https://jvns.ca/blog/2017/03/26/bash-quirks/
    by @b0rk
----
  status: |
    I investigate Diaspora* as an alternate social network.
    Anyone there?
    https://diasp.eu/public/YesIKnowIT
    #Diaspora @joindiaspora
    #YesIKnowIT
----
  event:
    repeat: { days: 180 }
  status: |
    #Vim is great.
    I like #tmux more and more.

    How could it be to use them both at the same time?
    https://blog.bugsnag.com/tmux-and-vim/
    by @keeganlow
----
  status: |
    A #Mastodon instance for #Linux Lovers
    https://linuxrocks.online/about

    Try that new #SocialNetwork and follow me there https://yesik.it/mastodon
    #YesIKnowIT
----
  status: |
    "I want to learn Linux. Is Kali right for me?"
    Yes? No? Is that so simple?

    https://itsfoss.com/kali-linux-review/

    #Linux #Kali @itsfoss2
    #YesIKnowIT
----
  status: |
    Glob patterns, from the basics to subtle corner cases:
    https://www.yesik.it/EP11

    #Linux #Shell #Bash #GlobPattern
    #YesIKnowIT
----
  event:
    repeat: { days: 180 }
  status: |
    Very great description of the difference between VMs and Containers
    by @mikegcoleman
    https://blog.docker.com/2016/03/containers-are-not-vms/

    #Docker #Containers
----
  status: |
    What is #Virtualization?
    And how does that relate to #Emulation, #Containers and #CloudComputing?

    https://www.yesik.it/EP12
    #YesIKnowIT
----
  event:
    repeat: { days: 180 }
  status: |
    Different does not mean better or worst. It just means different.

    https://www.linux.com/learn/intro-to-linux/2017/6/what-nosql
    by @CarlaSchroder

    #SQL #NoSQL
----
  status: |
    #VM #Containers #Emulation #Wine?
    Which virtualization technology is the best for YOUR needs?

    https://yesik.it/VIRT101

    #CheatSheet
    #YesIKnowIT
----
  status: |
    Print odd lines
    seq 10 | sed -n 'P;N'

    #Shell #Sed #Linux
----
  status: |
    Print even lines
    seq 10 | sed -n '1b;P;N'

    #Shell #Sed #Linux
----
  status: |
    My #Bash book available both as #PaperBook and #eBook

    https://yesik.it/BASH-IT-OUT/PAPER
    https://yesik.it/BASH-IT-OUT/PDF
    https://yesik.it/BASH-IT-OUT
    @itsfoss2
    #Linux #Shell #Puzzle #Book
    #YesIKnowIT
----
  event:
    repeat: { days: 180 }
  status: |
    split and csplit -- old friends, I used a lot in the 1.44MB floppy disk era...

    https://www.linux.com/learn/intro-to-linux/2017/8/splitting-and-re-assembling-files-linux
    by @CarlaSchroder

    #Linux #Unix #Split #csplit
----
  status: |
    In AWK an action without associated pattern defaults to 1.
    So those two commands are the same:

    seq 10 | awk '{print}'
    seq 10 | awk '1 {print}'

    #Shell #AWK
----
  status: |
    In AWK a pattern without associated action defaults to '{ print }':
    So those two commands are the same:

    seq 10 | awk /1/ is the same as
    seq 10 | awk '/1/ {print}'

    #Shell #AWK
----
  status: |
    Three completly different AWK programs:

    seq 10 | awk '1 { print }'
    seq 10 | awk '/1/ { print }'
    seq 10 | awk 'NR==1 { print }'

    #Shell #AWK #regex
----
  status: |
    #OpenStack is a complex and somewhat frightening beast
    https://opensource.com/resources/what-is-openstack
----
  status: |
    If you ever had to connect to an Oracle backend, you may know how painful it used to be to set up an Oracle Instance on your test/dev host.

    Thanks to @Docker, it is now several orders of magnitude simpler!

    https://yesik.it/EP18

    #Oracle #Database
    #Docker #Container
    #Linux
----
  status: |
    Fine tune Linux Kernel I/O by setting up dirty page parameters.

    https://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/

    #Linux #Kernel #Cache #Disk #Tuning
	#! INIT
	PS1="sh$ "
	rm -f tweet.*.yaml
	rm -f tweet.*.txt
	rm -f tweet.???
	rm -f xx??
	echo BEGIN

	#! POST
	sed -E -e '1,/^BEGIN$/d' -e '/^sh\$ exit$/d' -e 's/^sh\$[ \t]*$//'

	#= EXAMPLE-0
	awk < tweets.yaml '
	/----/ { OUTPUT="tweet." (N++) ".yaml" }
	{ print > OUTPUT }
	'

	ls -l tweet.*.yaml

	#= EXAMPLE-1
	# tag::A[]
	csplit tweets.yaml /----/
	#end::A[]

	# tag::B[]
	ls -l xx0*
	#end::B[]
	#= EXAMPLE-2
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	/----/

	ls -l tweet.*


	#= EXAMPLE-3
	rm tweet.*
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/

	ls -l tweet.*

	#= EXAMPLE-4
	# tag::A[]
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/ /----/ /----/
	# end::A[]
	# tag::B[]
	ls -l tweet.???.yaml
	# end::B[]

	#= EXAMPLE-5
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/ '{*}'

	#= EXAMPLE-6A
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/ '{6}'

	#= EXAMPLE-7A
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/ '{999}'

	ls tweet.*

	#= EXAMPLE-7B
	touch tweet.002.yaml
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	/----/ '{999}'

	ls tweet.*

	#= EXAMPLE-8A
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	/----/ '{999}'

	ls tweet.*

	#= EXAMPLE-8B
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	/----/ '{999}'
	# tag::A[]
	diff -s tweets.yaml <(cat tweet.*)
	# end::A[]

	#= EXAMPLE-9A
	csplit tweets.txt \
	--prefix='tweet.' --suffix-format='%03d.txt' \
	--elide-empty-files \
	--keep-files \
	2 '{*}'

	#= EXAMPLE-9B
	csplit tweets.txt \
	--prefix='tweet.' --suffix-format='%03d.txt' \
	--elide-empty-files \
	--keep-files \
	2 '{*}'

	# tag::A[]
	diff -s tweets.txt <(cat tweet.*.txt)
	# end::A[]

	#= EXAMPLE-10A
	csplit tweets.txt --keep-files 2 2 2 2 2

	#= EXAMPLE-10B
	csplit tweets.txt --keep-files 2 4 6 8 10

	#= EXAMPLE-10C
	csplit tweets.txt --keep-files 2 '{4}'

	#= EXAMPLE-11
	tr [:lower:] [:upper:] < tweets.txt \| csplit - \
	--prefix='tweet.' --suffix-format='%03d.txt' \
	--elide-empty-files \
	--keep-files \
	2 '{3}'

	head tweet.???.txt

	#= EXAMPLE-12C
	# Keep only the third and fourth tweets
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	%----% '{2}' /----/ '{2}' %----% '{*}'

	head tweet.00[012].yaml

	#= EXAMPLE-12B
	# Skip the first two tweets
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	%----% '{2}' /----/ '{2}'

	head tweet.00[012].yaml

	#= EXAMPLE-12A
	# Keep only the first two tweets
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	/----/ '{2}' %----% '{*}'

	head tweet.00[012].yaml

	#= EXAMPLE-13A
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	%----%+1 '{2}' /----/+1 '{2}' %----% '{*}'

	head tweet.00[012].yaml

	#= EXAMPLE-13B
	csplit tweets.yaml \
	--prefix='tweet.' --suffix-format='%03d.yaml' \
	--elide-empty-files \
	--keep-files \
	%----%+1 '{2}' /----/+1 '{2}' %----% '{*}'

	head tweet.00[012].yaml
	#!/usr/bin/awk -f

	function flush() {
	if (status) {
	print "{" repeat "}"
	print status
	}

	reset();
	}

	function reset() {
	instatus = 0;
	repeat = "";
	status = "";
	}

	BEGIN {
	reset();
	}

	/----/ { flush(); next }
	/repeat:/ { repeat = " " $3 $4 " "; next }
	/status:/ { instatus = 1; next }

	instatus {
	if (status)
	status = status "\\n";

	text = $0
	gsub(/^[ \t]+/, "", text)
	status = status text
	}



	END { flush() }
	#!/usr/bin/awk -f


	function send(text) {
	if (!DIRTY) {
	gsub(/^[ \t\n]+/,"", text);
	}
	gsub(/[ \t\n]$/,"", text);

	if (text) {
	COMMAND = "bash -i 2>&1";

	gsub(/[\n]+$/, "", POST);
	if (!POST)
	POST = "cat"

	COMMAND = COMMAND " \| " POST " > " OUTFILE;

	print text \| COMMAND;

	DIRTY=1;
	}
	}

	function setOutFile(file) {
	if(DIRTY) close(COMMAND);

	DIRTY=0;
	OUTFILE = file;
	}

	BEGIN {
	OUTFILE = "example"

	STATES["INIT"] = ++_ID;
	STATES["WORK"] = ++_ID;
	STATES["POST"] = ++_ID;
	}

	/^#=/ {
	STATE = STATES["WORK"];
	BUFFER = "";
	FILE = $1 $2;
	gsub(/^#=[ \t]*/, "", FILE);
	setOutFile(FILE);
	send(INIT);
	DIRTY = 0;
	next;
	}

	/^#![ \t]*INIT/ {
	STATE = STATES["INIT"];
	next
	}

	/^#![ \t]*POST/ {
	STATE = STATES["POST"];
	next
	}

	STATE == STATES["INIT"] {
	INIT = INIT $0 "\n"
	}

	STATE == STATES["POST"] {
	POST = POST $0 "\n"
	}

	STATE == STATES["WORK"] {
	BUFFER = BUFFER $0 "\n"
	}

	STATE == STATES["WORK"] && /[^ \t]/ {
	send(BUFFER);
	BUFFER = "";
	}
	{ days:180 }
	Still hesitating between #Vim and #Emacs?\nWhy not take a look at #spacemacs?\n\nhttp://spacemacs.org/
	{}
	Print the first column of a space-separated data file:\nawk '{print $1}' data.txt # Print out just the first column\n\nFor some unknown reason, I find that easier to remember than:\ncut -f1 data.txt\n\n#Linux #AWK #Cut
	{}
	For the #shell #beginners :\n« #GlobPatterns : how to move hundreds of files in not time [1/3] »\nhttps://youtu.be/TvW8DiEmTcQ\n\n#Unix #Linux\n#YesIKnowIT
	{}
	Want to know the oldest file in your disk?\n\nfind / -type f -printf '%TFT%.8TT %p\n' \| sort \| less\n(should work on any Single UNIX Specification compliant system)\n#UNIX #Linux
	{}
	When using the find command, use `-iname` instead of `-name` for case-insensitive search\n#Unix #Linux #Shell #Find
	{}
	From a POSIX shell `$OLDPWD` holds the name of the previous working directory:\ncd /tmp\necho You are here: $PWD\necho You were here: $OLDPWD\ncd $OLDPWD\n\n#Unix #Linux #Shell #cd
	{}
	From a POSIX shell, "cd" is a shorthand for cd $HOME\n#Unix #Linux #Shell #cd
	{}
	How to move hundreds of files in no time?\nUsing the find command!\n\nhttps://youtu.be/zmEFXjyzaQk\n#Unix #Linux #Move #Files #Find\n#YesIKnowIT
	{}
	If your shell supports history, use "!-1" to repeat the last command.\n"!!" is a shorthand for that too\n#Unix #Linux #Shell
	{}
	If your shell supports job control, type <CTRL-z> "bg" from its parent shell to send a process to the background\n#Shell #Bash #JobControl
	{}
	`ls -lt` will show files ordered by modification date — most recent first.\n\n#ls #shell #linux
	{}
	`ls -r` will reverse the normal order of the ls output. Try `ls -rlt` for example.\n\n#ls #shell #linux
	{}
	In the Bash, pressing "ctrl-x ctrl-v" will display its version informations.\n\n#bash #linux
	{}
	You know the "globstar" feature of your Bash ?\nLet's talk about that !\nhttps://youtu.be/N8zAA7GG56g\n\n#Linux #Bash #Globstar
	{}
	20 files to rename. 5 seconds per file. 1"40 of boring work?\nNo: 15 seconds if you know the right command\nhttps://yesik.it/EP04\n\n#Shell #Rename #PRename
	{}
	`less -R` will handle gracefully ANSI "color" escape sequences:\nls --color=always /tmp \| less -R\n\n#Linux #Shell #ls
	{}
	`‥ \| read ‥` is not portable between #zsh and #bash\n\nCompare in both shells :\necho 1 \| read X; echo $X
	{}
	In Bash the pseudo-variable RANDOM returns a pseudo-random integer in the [0;32767] range\n\necho $RANDOM\n\n#Bash #Random
	{}
	With Bash history, `^str1^str2^` will repeat the previous command replacing `str1` by `str2`\n\necho 1223\n^2^4^\n\n#Bash
	{ days:200 }
	Nice introductory article on Awk by Justin Ellingwood (@jmellingwood):\nhttps://www.digitalocean.com/community/tutorials/how-to-use-the-awk-language-to-manipulate-text-in-linux
	{}
	If you don't know what is #Awk or how it could help you processing text files, then you NEED that little introduction:\nhttps://youtu.be/PUYS6MO4p7Y\n\n#Linux #Shell #AWK\n#YesIKnowIT
	{}
	In Bash `$(<file)` is equivalent to `$(cat file)`, but faster:\n\nP=( $(</etc/passwd) )\necho ${P[0]}\n\n#Bash #Linux #Cat
	{}
	The #Bash has the notion of "integer" variable:\n\ndeclare A=1; declare -i B=2\nA+=3; B+=4\necho $A $B\n⇒ 13 6\n\n#Shell
	{}
	In Bash,\n`~+` is expanded to the content of `PWD`\n`~-` is expanded to the content of `OLDPWD`\n\ncd /tmp\necho You are here: ~+\necho You were here: ~-\n\n#Bash #Shell
	{ days:65 }
	Do you know I have a "Bash and Linux Command Line" course On #Udemy?\nTake a look here for a discount:\nhttps://yesik.it/BSH101
	{}
	In #Bash, to edit the last three commands in your favorite EDITOR type:\n\nfc -3 0\n\nWhen leaving the editor, commands are executed
	{}
	To leave #vim with a non-zero exit code use `:cq`.\n\nUseful to abort a #Git commit or a #Bash `fc` command
	{}
	So, you don't know yet the `grep` command ?\nhttps://youtu.be/HBNNO92Juw4\n\n#Shell #Linux #Grep\n#YesIKnowIT
	{ days:180 }
	Nice introduction to sed, the Stream EDitor :\n\nhttps://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux\nby @jmellingwood
	{}
	Not all you can do with sed, but a cool reminder for the most basic use cases:\nhttps://www.yesik.it/SEDCS1\n\n#sed #cheatsheet
	{}
	I think I use the `sed` command daily. And you?\n\nhttps://www.yesik.it/EP07\n#Shell #Linux #Sed\n#YesIKnowIT
	{}
	Delete the last line of a file:\nsed '$d' file\n\n#Shell #Sed #Linux
	{}
	Delete all but the last line of a file:\nsed -n '$p' file\n\n#Shell #Sed #Linux
	{}
	Display the first 5 lines of a file:\nsed '5q' file\n\n#Shell #Sed #Linux
	{}
	Hello,\nI'm Sylvain...\n... and I'm a Vim Addict.\n\nhttps://itsfoss.com/pro-vim-tips/ by @Yes_I_Know_IT\n#Vim #TextEditor #Linux\n#YesIKnowIT
	{}
	Centering text on 80 columns with stars:\nsed -E ':x\ns/^.{,80}$/&/\ns/^.{,80}$/&/\ntx\n' file\n\n#Shell #Sed #Linux
	{}
	Right-align text on 80 columns:\nsed -E ':a /.{80}/!{s/^/ /;ba}' file\n\n#Shell #Sed #Linux
	{}
	The sed substitution (s) command is by far the most useful. But did you know ALL these patterns:\nhttps://www.yesik.it/EP08\n\n#Linux #Sed\n#YesIKnowIT
	{}
	ddrescue is one of the best tools to recover damaged disk (HD or optical).\n/!\ Don't miss the "log" feature for multipass recovery!\nhttps://www.linux.com/learn/intro-to-linux/2017/3/gnu-ddrescue-best-damaged-drive-rescue\n\n#HD #DVD #Rescue #RIP #ddrescue #Linux
	{}
	In a #sed substitution pattern, you can use any character as a separator instead of /\nUseful for path or urls:\ns!/usr/local!/opt!\n\n#Linux #UNIX
	{}
	Put emphasis around the Beattles\nsed -E 's!(John\|Paul\|George\|Ringo)!<em>&</em>!g' file\n\n#Sed #Linux\nfrom https://www.yesik.it/EP08
	{}
	Looking for an explanation of what is the kernel and how it relates to userspace applications?\nTake a look at that video:\nhttps://yesik.it/EP09\n\n#Kernel #Linux\n#YesIKnowIT
	{}
	GNU sed has a nice 'e' modifier for substitutions:\nsed 's/.*/date +%F -d &/e' << EOT\nnow\ntomorrow\nyesterday\nEOT\n\n#GNU #sed #Linux
	{ days:180 }
	Bash scripting 101:\nhttps://jvns.ca/blog/2017/03/26/bash-quirks/\nby @b0rk
	{}
	I investigate Diaspora* as an alternate social network.\nAnyone there?\nhttps://diasp.eu/public/YesIKnowIT\n#Diaspora @joindiaspora\n#YesIKnowIT
	{ days:180 }
	#Vim is great.\nI like #tmux more and more.\n\nHow could it be to use them both at the same time?\nhttps://blog.bugsnag.com/tmux-and-vim/\nby @keeganlow
	{}
	A #Mastodon instance for #Linux Lovers\nhttps://linuxrocks.online/about\n\nTry that new #SocialNetwork and follow me there https://yesik.it/mastodon\n#YesIKnowIT
	{}
	"I want to learn Linux. Is Kali right for me?"\nYes? No? Is that so simple?\n\nhttps://itsfoss.com/kali-linux-review/\n\n#Linux #Kali @itsfoss2\n#YesIKnowIT
	{}
	Glob patterns, from the basics to subtle corner cases:\nhttps://www.yesik.it/EP11\n\n#Linux #Shell #Bash #GlobPattern\n#YesIKnowIT
	{ days:180 }
	Very great description of the difference between VMs and Containers\nby @mikegcoleman\nhttps://blog.docker.com/2016/03/containers-are-not-vms/\n\n#Docker #Containers
	{}
	What is #Virtualization?\nAnd how does that relate to #Emulation, #Containers and #CloudComputing?\n\nhttps://www.yesik.it/EP12\n#YesIKnowIT
	{ days:180 }
	Different does not mean better or worst. It just means different.\n\nhttps://www.linux.com/learn/intro-to-linux/2017/6/what-nosql\nby @CarlaSchroder\n\n#SQL #NoSQL
	{}
	#VM #Containers #Emulation #Wine?\nWhich virtualization technology is the best for YOUR needs?\n\nhttps://yesik.it/VIRT101\n\n#CheatSheet\n#YesIKnowIT
	{}
	Print odd lines\nseq 10 \| sed -n 'P;N'\n\n#Shell #Sed #Linux
	{}
	Print even lines\nseq 10 \| sed -n '1b;P;N'\n\n#Shell #Sed #Linux
	{}
	My #Bash book available both as #PaperBook and #eBook\n\nhttps://yesik.it/BASH-IT-OUT/PAPER\nhttps://yesik.it/BASH-IT-OUT/PDF\nhttps://yesik.it/BASH-IT-OUT\n@itsfoss2\n#Linux #Shell #Puzzle #Book\n#YesIKnowIT
	{ days:180 }
	split and csplit -- old friends, I used a lot in the 1.44MB floppy disk era...\n\nhttps://www.linux.com/learn/intro-to-linux/2017/8/splitting-and-re-assembling-files-linux\nby @CarlaSchroder\n\n#Linux #Unix #Split #csplit
	{}
	In AWK an action without associated pattern defaults to 1.\nSo those two commands are the same:\n\nseq 10 \| awk '{print}'\nseq 10 \| awk '1 {print}'\n\n#Shell #AWK
	{}
	In AWK a pattern without associated action defaults to '{ print }':\nSo those two commands are the same:\n\nseq 10 \| awk /1/ is the same as\nseq 10 \| awk '/1/ {print}'\n\n#Shell #AWK
	{}
	Three completly different AWK programs:\n\nseq 10 \| awk '1 { print }'\nseq 10 \| awk '/1/ { print }'\nseq 10 \| awk 'NR==1 { print }'\n\n#Shell #AWK #regex
	{}
	#OpenStack is a complex and somewhat frightening beast\nhttps://opensource.com/resources/what-is-openstack
	{}
	If you ever had to connect to an Oracle backend, you may know how painful it used to be to set up an Oracle Instance on your test/dev host.\n\nThanks to @Docker, it is now several orders of magnitude simpler!\n\nhttps://yesik.it/EP18\n\n#Oracle #Database\n#Docker #Container\n#Linux
	{}
	Fine tune Linux Kernel I/O by setting up dirty page parameters.\n\nhttps://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/\n\n#Linux #Kernel #Cache #Disk #Tuning
	----
	event:
	repeat: { days: 180 }
	status: \|
	Still hesitating between #Vim and #Emacs?
	Why not take a look at #spacemacs?

	http://spacemacs.org/
	----
	status: \|
	Print the first column of a space-separated data file:
	awk '{print $1}' data.txt # Print out just the first column

	For some unknown reason, I find that easier to remember than:
	cut -f1 data.txt

	#Linux #AWK #Cut
	----
	status: \|
	For the #shell #beginners :
	« #GlobPatterns : how to move hundreds of files in not time [1/3] »
	https://youtu.be/TvW8DiEmTcQ

	#Unix #Linux
	#YesIKnowIT
	----
	status: \|
	Want to know the oldest file in your disk?

	find / -type f -printf '%TFT%.8TT %p\n' \| sort \| less
	(should work on any Single UNIX Specification compliant system)
	#UNIX #Linux
	----
	status: \|
	When using the find command, use `-iname` instead of `-name` for case-insensitive search
	#Unix #Linux #Shell #Find
	----
	status: \|
	From a POSIX shell `$OLDPWD` holds the name of the previous working directory:
	cd /tmp
	echo You are here: $PWD
	echo You were here: $OLDPWD
	cd $OLDPWD

	#Unix #Linux #Shell #cd
	----
	status: \|
	From a POSIX shell, "cd" is a shorthand for cd $HOME
	#Unix #Linux #Shell #cd
	----
	status: \|
	How to move hundreds of files in no time?
	Using the find command!

	https://youtu.be/zmEFXjyzaQk
	#Unix #Linux #Move #Files #Find
	#YesIKnowIT
	----
	status: \|
	If your shell supports history, use "!-1" to repeat the last command.
	"!!" is a shorthand for that too
	#Unix #Linux #Shell
	----
	status: \|
	If your shell supports job control, type <CTRL-z> "bg" from its parent shell to send a process to the background
	#Shell #Bash #JobControl
	----
	status: \|
	`ls -lt` will show files ordered by modification date — most recent first.

	#ls #shell #linux
	----
	status: \|
	`ls -r` will reverse the normal order of the ls output. Try `ls -rlt` for example.

	#ls #shell #linux
	----
	status: \|
	In the Bash, pressing "ctrl-x ctrl-v" will display its version informations.

	#bash #linux
	----
	status: \|
	You know the "globstar" feature of your Bash ?
	Let's talk about that !
	https://youtu.be/N8zAA7GG56g

	#Linux #Bash #Globstar
	----
	status: \|
	20 files to rename. 5 seconds per file. 1"40 of boring work?
	No: 15 seconds if you know the right command
	https://yesik.it/EP04

	#Shell #Rename #PRename
	----
	status: \|
	`less -R` will handle gracefully ANSI "color" escape sequences:
	ls --color=always /tmp \| less -R

	#Linux #Shell #ls
	----
	status: \|
	`‥ \| read ‥` is not portable between #zsh and #bash

	Compare in both shells :
	echo 1 \| read X; echo $X
	----
	status: \|
	In Bash the pseudo-variable RANDOM returns a pseudo-random integer in the [0;32767] range

	echo $RANDOM

	#Bash #Random
	----
	status: \|
	With Bash history, `^str1^str2^` will repeat the previous command replacing `str1` by `str2`

	echo 1223
	^2^4^

	#Bash
	----
	event:
	repeat: { days: 200 }
	status: \|
	Nice introductory article on Awk by Justin Ellingwood (@jmellingwood):
	https://www.digitalocean.com/community/tutorials/how-to-use-the-awk-language-to-manipulate-text-in-linux
	----
	status: \|
	If you don't know what is #Awk or how it could help you processing text files, then you NEED that little introduction:
	https://youtu.be/PUYS6MO4p7Y

	#Linux #Shell #AWK
	#YesIKnowIT
	----
	status: \|
	In Bash `$(<file)` is equivalent to `$(cat file)`, but faster:

	P=( $(</etc/passwd) )
	echo ${P[0]}

	#Bash #Linux #Cat
	----
	status: \|
	The #Bash has the notion of "integer" variable:

	declare A=1; declare -i B=2
	A+=3; B+=4
	echo $A $B
	⇒ 13 6

	#Shell
	----
	status: \|
	In Bash,
	`~+` is expanded to the content of `PWD`
	`~-` is expanded to the content of `OLDPWD`

	cd /tmp
	echo You are here: ~+
	echo You were here: ~-

	#Bash #Shell
	----
	event:
	repeat: { days: 65 }
	status: \|
	Do you know I have a "Bash and Linux Command Line" course On #Udemy?
	Take a look here for a discount:
	https://yesik.it/BSH101
	----
	status: \|
	In #Bash, to edit the last three commands in your favorite EDITOR type:

	fc -3 0

	When leaving the editor, commands are executed
	----
	status: \|
	To leave #vim with a non-zero exit code use `:cq`.

	Useful to abort a #Git commit or a #Bash `fc` command
	----
	status: \|
	So, you don't know yet the `grep` command ?
	https://youtu.be/HBNNO92Juw4

	#Shell #Linux #Grep
	#YesIKnowIT
	----
	event:
	repeat: { days: 180 }
	status: \|
	Nice introduction to sed, the Stream EDitor :

	https://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux
	by @jmellingwood
	----
	status: \|
	Not all you can do with sed, but a cool reminder for the most basic use cases:
	https://www.yesik.it/SEDCS1

	#sed #cheatsheet
	----
	status: \|
	I think I use the `sed` command daily. And you?

	https://www.yesik.it/EP07
	#Shell #Linux #Sed
	#YesIKnowIT
	----
	status: \|
	Delete the last line of a file:
	sed '$d' file

	#Shell #Sed #Linux
	----
	status: \|
	Delete all but the last line of a file:
	sed -n '$p' file

	#Shell #Sed #Linux
	----
	status: \|
	Display the first 5 lines of a file:
	sed '5q' file

	#Shell #Sed #Linux
	----
	status: \|
	Hello,
	I'm Sylvain...
	... and I'm a Vim Addict.

	https://itsfoss.com/pro-vim-tips/ by @Yes_I_Know_IT
	#Vim #TextEditor #Linux
	#YesIKnowIT
	----
	status: \|
	Centering text on 80 columns with stars:
	sed -E ':x
	s/^.{,80}$/*&/
	s/^.{,80}$/&*/
	tx
	' file

	#Shell #Sed #Linux
	----
	status: \|
	Right-align text on 80 columns:
	sed -E ':a /.{80}/!{s/^/ /;ba}' file

	#Shell #Sed #Linux
	----
	status: \|
	The sed substitution (s) command is by far the most useful. But did you know ALL these patterns:
	https://www.yesik.it/EP08

	#Linux #Sed
	#YesIKnowIT
	----
	status: \|
	ddrescue is one of the best tools to recover damaged disk (HD or optical).
	/!\ Don't miss the "log" feature for multipass recovery!
	https://www.linux.com/learn/intro-to-linux/2017/3/gnu-ddrescue-best-damaged-drive-rescue

	#HD #DVD #Rescue #RIP #ddrescue #Linux
	----
	status: \|
	In a #sed substitution pattern, you can use any character as a separator instead of /
	Useful for path or urls:
	s!/usr/local!/opt!

	#Linux #UNIX
	----
	status: \|
	Put emphasis around the Beattles
	sed -E 's!(John\|Paul\|George\|Ringo)!<em>&</em>!g' file

	#Sed #Linux
	from https://www.yesik.it/EP08
	----
	status: \|
	Looking for an explanation of what is the kernel and how it relates to userspace applications?
	Take a look at that video:
	https://yesik.it/EP09

	#Kernel #Linux
	#YesIKnowIT
	----
	status: \|
	GNU sed has a nice 'e' modifier for substitutions:
	sed 's/.*/date +%F -d &/e' << EOT
	now
	tomorrow
	yesterday
	EOT

	#GNU #sed #Linux
	----
	event:
	repeat: { days: 180 }
	status: \|
	Bash scripting 101:
	https://jvns.ca/blog/2017/03/26/bash-quirks/
	by @b0rk
	----
	status: \|
	I investigate Diaspora* as an alternate social network.
	Anyone there?
	https://diasp.eu/public/YesIKnowIT
	#Diaspora @joindiaspora
	#YesIKnowIT
	----
	event:
	repeat: { days: 180 }
	status: \|
	#Vim is great.
	I like #tmux more and more.

	How could it be to use them both at the same time?
	https://blog.bugsnag.com/tmux-and-vim/
	by @keeganlow
	----
	status: \|
	A #Mastodon instance for #Linux Lovers
	https://linuxrocks.online/about

	Try that new #SocialNetwork and follow me there https://yesik.it/mastodon
	#YesIKnowIT
	----
	status: \|
	"I want to learn Linux. Is Kali right for me?"
	Yes? No? Is that so simple?

	https://itsfoss.com/kali-linux-review/

	#Linux #Kali @itsfoss2
	#YesIKnowIT
	----
	status: \|
	Glob patterns, from the basics to subtle corner cases:
	https://www.yesik.it/EP11

	#Linux #Shell #Bash #GlobPattern
	#YesIKnowIT
	----
	event:
	repeat: { days: 180 }
	status: \|
	Very great description of the difference between VMs and Containers
	by @mikegcoleman
	https://blog.docker.com/2016/03/containers-are-not-vms/

	#Docker #Containers
	----
	status: \|
	What is #Virtualization?
	And how does that relate to #Emulation, #Containers and #CloudComputing?

	https://www.yesik.it/EP12
	#YesIKnowIT
	----
	event:
	repeat: { days: 180 }
	status: \|
	Different does not mean better or worst. It just means different.

	https://www.linux.com/learn/intro-to-linux/2017/6/what-nosql
	by @CarlaSchroder

	#SQL #NoSQL
	----
	status: \|
	#VM #Containers #Emulation #Wine?
	Which virtualization technology is the best for YOUR needs?

	https://yesik.it/VIRT101

	#CheatSheet
	#YesIKnowIT
	----
	status: \|
	Print odd lines
	seq 10 \| sed -n 'P;N'

	#Shell #Sed #Linux
	----
	status: \|
	Print even lines
	seq 10 \| sed -n '1b;P;N'

	#Shell #Sed #Linux
	----
	status: \|
	My #Bash book available both as #PaperBook and #eBook

	https://yesik.it/BASH-IT-OUT/PAPER
	https://yesik.it/BASH-IT-OUT/PDF
	https://yesik.it/BASH-IT-OUT
	@itsfoss2
	#Linux #Shell #Puzzle #Book
	#YesIKnowIT
	----
	event:
	repeat: { days: 180 }
	status: \|
	split and csplit -- old friends, I used a lot in the 1.44MB floppy disk era...

	https://www.linux.com/learn/intro-to-linux/2017/8/splitting-and-re-assembling-files-linux
	by @CarlaSchroder

	#Linux #Unix #Split #csplit
	----
	status: \|
	In AWK an action without associated pattern defaults to 1.
	So those two commands are the same:

	seq 10 \| awk '{print}'
	seq 10 \| awk '1 {print}'

	#Shell #AWK
	----
	status: \|
	In AWK a pattern without associated action defaults to '{ print }':
	So those two commands are the same:

	seq 10 \| awk /1/ is the same as
	seq 10 \| awk '/1/ {print}'

	#Shell #AWK
	----
	status: \|
	Three completly different AWK programs:

	seq 10 \| awk '1 { print }'
	seq 10 \| awk '/1/ { print }'
	seq 10 \| awk 'NR==1 { print }'

	#Shell #AWK #regex
	----
	status: \|
	#OpenStack is a complex and somewhat frightening beast
	https://opensource.com/resources/what-is-openstack
	----
	status: \|
	If you ever had to connect to an Oracle backend, you may know how painful it used to be to set up an Oracle Instance on your test/dev host.

	Thanks to @Docker, it is now several orders of magnitude simpler!

	https://yesik.it/EP18

	#Oracle #Database
	#Docker #Container
	#Linux
	----
	status: \|
	Fine tune Linux Kernel I/O by setting up dirty page parameters.

	https://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/

	#Linux #Kernel #Cache #Disk #Tuning