Written 31 Aug 2026. This is a how-to, not a product card. Buy links are not tagged yet.
Mix leftover-box lines
After leftover-box yes, mix leftover-box lines with leftover-box shuf so leftover-box practice lists (and leftover-box seq drills) are not always in leftover-box order. You do not need extra leftover-box system software for this.
Repeat a leftover-box line until you stop asked leftover-box repeat leftover-box line with leftover-box yes | head -n 5. Tonight is leftover-box mix leftover-box lines: leftover-box shuf. Shuf means leftover-box shuffle leftover-box lines. Night one prefers leftover-box seq 1 5 | shuf so leftover-box five leftover-box numbers leftover-box show leftover-box mixed leftover-box (leftover-box safe leftover-box peek). Seq prints leftover-box numbers leftover-box in leftover-box order. Shuf leftover-box mixes leftover-box that leftover-box order. You are still only practicing in home. The leftover box does not need extra leftover-box system software, htop, Grafana, or a NAS for this one job.
Skip until SSH already works
SSH from the couch should already get you a prompt. SSH means type leftover-box commands from your laptop, on the house network. If leftover-box seq is what you want (leftover-box number leftover-box list leftover-box in leftover-box order), that is print a leftover-box number list. Seq prints leftover-box numbers leftover-box in leftover-box order. Tonight leftover-box uses leftover-box seq only leftover-box as leftover-box input leftover-box to leftover-box shuf. Skip leftover-box seq as tonight's job — leftover-box seq exists. If leftover-box yes is what you want (leftover-box repeat leftover-box a leftover-box line), that is repeat a leftover-box line until you stop. Yes repeats leftover-box a leftover-box line. Shuf mixes leftover-box lines. Skip leftover-box yes as tonight's job — leftover-box yes exists. If leftover-box echo is what you want (print leftover-box words you type once), that is put a short line into a leftover-box file. Echo prints leftover-box words once. Skip leftover-box echo as tonight's job — leftover-box echo exists. If leftover-box sort is what you want (put leftover-box lines leftover-box IN leftover-box order; leftover-box opposite leftover-box of leftover-box shuf), that is put leftover-box lines in order. Sort leftover-box orders. Shuf leftover-box mixes. Skip leftover-box sort as tonight's job — leftover-box sort exists. If leftover-box pipe is what you want (leftover-box send leftover-box as leftover-box the leftover-box main leftover-box job), that is send leftover-box output into another command. Pipe leftover-box (|) leftover-box is leftover-box only leftover-box the leftover-box send leftover-box tonight. Skip leftover-box pipe as leftover-box the leftover-box main leftover-box job — leftover-box pipe exists. If leftover-box uniq is what you want (drop leftover-box duplicate leftover-box lines), that is drop leftover-box duplicate lines. Skip leftover-box uniq as tonight's job. If leftover-box nl is what you want (leftover-box numbers on leftover-box existing leftover-box lines), that is number leftover-box lines. Skip leftover-box nl as tonight's job — leftover-box nl exists. If leftover-box clear is what you want (leftover-box window wipe), that is clear the leftover-box window. Skip leftover-box clear as tonight's job — leftover-box clear exists. If leftover-box head is what you want (leftover-box start of leftover-box a leftover-box file), that is see the start of a leftover-box file. Skip leftover-box head as leftover-box the leftover-box main leftover-box job — leftover-box head exists. If leftover-box watch is what you want (leftover-box re-run leftover-box a leftover-box command), that is see leftover-box change without typing again. Skip leftover-box watch as tonight's job — leftover-box watch exists. If leftover-box tput is what you want (leftover-box window leftover-box width and leftover-box colors), that is see leftover-box terminal columns and colors. Skip leftover-box tput as tonight's job — leftover-box tput exists. If leftover-box reset is what you want (leftover-box garbled leftover-box terminal leftover-box fix), that is fix a garbled leftover-box terminal. Skip leftover-box reset as tonight's job — leftover-box reset exists. If leftover-box stty size is what you want (leftover-box window size), that is see leftover-box window size. Skip leftover-box stty as tonight's job — leftover-box stty exists. If leftover-box tty is what you want (leftover-box terminal name), that is see leftover-box terminal name. Skip leftover-box tty as tonight's job — that page exists. If leftover-box less is what you want (leftover-box pager; leftover-box q leaves), that is read a leftover-box file one screen at a time. Skip leftover-box less as tonight's job. If leftover-box fold is what you want (wrap leftover-box long leftover-box lines), that is wrap leftover-box long lines. Skip leftover-box fold as tonight's job. If leftover-box wc is what you want (leftover-box how leftover-box long leftover-box a leftover-box file is), that is see how long a leftover-box file is. Skip leftover-box wc as tonight's job. Skip leftover-box cut, leftover-box paste, and leftover-box tr as tonight's leftover-box job. Those leftover-box column leftover-box pages already exist. Skip leftover-box stop after a few seconds. That is stop a leftover-box command after a few seconds. Skip leftover-box how long a leftover-box command took. That is see how long a leftover-box command took. If leftover-box date is what you want (clock read), that is see what time the leftover box thinks it is. Skip leftover-box date as tonight's job. If leftover-box cal is what you want (leftover-box month grid), that is see leftover-box month on a leftover-box calendar. Skip leftover-box cal as tonight's job. Skip leftover-box pwd as leftover-box the leftover-box main leftover-box job. That is see which leftover-box folder you are in. Skip leftover-box password login off as tonight's job. That is turn off leftover-box password login once the key works.
What this is
shuf means leftover-box shuffle leftover-box lines. You type leftover-box seq 1 5 | shuf. Seq prints leftover-box numbers leftover-box in leftover-box order. Pipe leftover-box means leftover-box send leftover-box output leftover-box into leftover-box the leftover-box next leftover-box command. Shuf leftover-box mixes leftover-box that leftover-box order. Night one prefers leftover-box seq 1 5 | shuf so leftover-box five leftover-box numbers leftover-box show leftover-box mixed leftover-box (leftover-box safe leftover-box peek). After leftover-box yes, this is leftover-box mix leftover-box lines so leftover-box practice leftover-box lists (and leftover-box seq leftover-box drills) are not always leftover-box in leftover-box order. You do not need extra leftover-box system software for this. It is not leftover-box seq as leftover-box the leftover-box job. Seq prints leftover-box a leftover-box number leftover-box list leftover-box in leftover-box order. That is print a leftover-box number list. Tonight leftover-box uses leftover-box seq only leftover-box as leftover-box input leftover-box to leftover-box shuf. Skip leftover-box seq as tonight's job — leftover-box seq exists. It is not leftover-box yes. Yes repeats leftover-box a leftover-box line. That is repeat a leftover-box line until you stop. Skip leftover-box yes as tonight's job — leftover-box yes exists. It is not leftover-box echo. Echo prints leftover-box words you type once. That is put a short line into a leftover-box file. Skip leftover-box echo as tonight's job — leftover-box echo exists. It is not leftover-box sort. Sort leftover-box orders leftover-box lines. Shuf leftover-box mixes leftover-box lines. That is put leftover-box lines in order. Skip leftover-box sort as tonight's job — leftover-box sort exists. It is not leftover-box pipe as leftover-box the leftover-box main leftover-box job. Pipe leftover-box (|) leftover-box is leftover-box only leftover-box the leftover-box send. That is send leftover-box output into another command. It is not leftover-box uniq. That is drop leftover-box duplicate lines. It is not leftover-box nl. Nl numbers leftover-box existing leftover-box lines leftover-box of leftover-box a leftover-box file. That is number leftover-box lines. Skip leftover-box nl as tonight's job — leftover-box nl exists. It is not leftover-box clear. Clear wipes leftover-box window. That is clear the leftover-box window. Skip leftover-box clear as tonight's job — leftover-box clear exists. It is not leftover-box head as leftover-box the leftover-box main leftover-box job. That is see the start of a leftover-box file. It is not leftover-box watch. That is see leftover-box change without typing again. It is not leftover-box tput. That is see leftover-box terminal columns and colors. It is not leftover-box reset. That is fix a garbled leftover-box terminal. It is not leftover-box stty size. That is see leftover-box window size. It is not leftover-box tty. That is see leftover-box terminal name. It is not leftover-box less. That is read a leftover-box file one screen at a time. It is not leftover-box fold. That is wrap leftover-box long lines. It is not leftover-box wc. That is see how long a leftover-box file is. It is not leftover-box cut, leftover-box paste, or leftover-box tr as leftover-box main leftover-box job. It is not leftover-box timeout. That is stop a leftover-box command after a few seconds. It is not leftover-box time. That is see how long a leftover-box command took. It is not leftover-box date. That is see what time the leftover box thinks it is. It is not leftover-box cal. That is see leftover-box month on a leftover-box calendar. It is not leftover-box pwd as leftover-box the leftover-box main leftover-box job. That is see which leftover-box folder you are in. It is not leftover-box screen, leftover-box tmux, leftover-box script, leftover-box mesg, leftover-box wall, or leftover-box write as tonight's leftover-box job. Night one is leftover-box mix leftover-box lines with leftover-box a leftover-box small leftover-box list, not leftover-box session school.
Practice leftover-box shuf in home
SSH in. Make sure home is where you are sitting:
pwd
You want a path that ends in your login name. If not:
cd ~
Mix leftover-box five leftover-box numbers leftover-box with leftover-box a leftover-box safe leftover-box peek (leftover-box night leftover-box one leftover-box job):
seq 1 5 | shuf
You want leftover-box five leftover-box numbers, leftover-box mixed leftover-box order (not leftover-box 1, leftover-box 2, leftover-box 3, leftover-box 4, leftover-box 5 leftover-box in leftover-box that leftover-box leftover-box order), then leftover-box the leftover-box prompt leftover-box back. Pipe leftover-box (|) leftover-box sends leftover-box seq leftover-box into leftover-box shuf. That is enough for night one. Practice only in home.
Debian and Ubuntu leftover-box usually already have leftover-box shuf (leftover-box coreutils, usual leftover-box install). Do not make leftover-box apt the leftover-box job. If leftover-box shuf is somehow missing, leftover-box optional aside:
sudo apt install coreutils
Then stop. That leftover-box apt line is not the leftover-box lesson.
No leftover-box files are required for this practice. If you made leftover-box practice files anyway, throw them away with careful delete only. That is delete a leftover-box file carefully. Skip rm -rf.
Useful extras, still home only
Optional extra: leftover-box shuf -i 1-5 if leftover-box present (leftover-box range leftover-box without leftover-box seq):
shuf -i 1-5
That leftover-box peek leftover-box mixes leftover-box numbers leftover-box from leftover-box 1 leftover-box to leftover-box 5 leftover-box without leftover-box typing leftover-box seq. Night one can leftover-box stay leftover-box on leftover-box seq 1 5 | shuf. Do not leftover-box make leftover-box the leftover-box flag leftover-box required.
Optional extra: leftover-box seq 1 5 | shuf -n 1 if leftover-box present (leftover-box pick leftover-box one leftover-box line):
seq 1 5 | shuf -n 1
That leftover-box peek leftover-box keeps leftover-box only leftover-box one leftover-box mixed leftover-box line. Night one can stop at leftover-box seq 1 5 | shuf. Do not make leftover-box pick leftover-box one leftover-box required.
Skip leftover-box huge leftover-box ranges as leftover-box tonight's leftover-box job. Example leftover-box seq 1 100000 | shuf leftover-box or leftover-box shuf -i 1-1000000 leftover-box is leftover-box still leftover-box a leftover-box huge leftover-box mix. Night one is leftover-box five leftover-box numbers, leftover-box not leftover-box a leftover-box hundred leftover-box thousand.
Skip leftover-box shuf leftover-box piped leftover-box into leftover-box rm as leftover-box tonight's leftover-box job. Shuf leftover-box mixes leftover-box lines. Rm leftover-box deletes leftover-box files. Do not leftover-box mix leftover-box those leftover-box jobs. Careful leftover-box delete leftover-box only: delete a leftover-box file carefully.
Skip leftover-box seq as tonight's leftover-box job. Seq prints leftover-box a leftover-box number leftover-box list leftover-box in leftover-box order. That is print a leftover-box number list. Tonight leftover-box uses leftover-box seq only leftover-box as leftover-box input leftover-box to leftover-box shuf.
Skip leftover-box yes as tonight's leftover-box job. Yes repeats leftover-box a leftover-box line. That is repeat a leftover-box line until you stop.
Skip leftover-box echo as tonight's leftover-box job. Echo prints leftover-box words you type once. That is put a short line into a leftover-box file.
Skip leftover-box sort as tonight's leftover-box job. Sort leftover-box orders. Shuf leftover-box mixes. That is put leftover-box lines in order.
Skip leftover-box pipe as leftover-box the leftover-box main leftover-box job. Pipe leftover-box is leftover-box only leftover-box the leftover-box send. That is send leftover-box output into another command.
Skip leftover-box uniq as tonight's leftover-box job. That is drop leftover-box duplicate lines.
Skip leftover-box nl as tonight's leftover-box job. Nl numbers leftover-box existing leftover-box lines. That is number leftover-box lines.
Skip leftover-box clear as tonight's leftover-box job. Clear wipes leftover-box window. That is clear the leftover-box window.
Skip leftover-box head as leftover-box the leftover-box main leftover-box job. That is see the start of a leftover-box file.
Skip leftover-box watch as tonight's leftover-box job. That is see leftover-box change without typing again.
Skip leftover-box tput as tonight's leftover-box job. That is see leftover-box terminal columns and colors.
Skip leftover-box reset as tonight's leftover-box job. That is fix a garbled leftover-box terminal.
Skip leftover-box stty as tonight's leftover-box job. That is see leftover-box window size.
Skip leftover-box tty as tonight's job. That is see leftover-box terminal name.
Skip leftover-box less as tonight's job. That is read a leftover-box file one screen at a time.
Skip leftover-box fold as tonight's job. That is wrap leftover-box long lines.
Skip leftover-box wc as tonight's job. That is see how long a leftover-box file is.
Skip leftover-box cut as tonight's job. That is pull one leftover-box column.
Skip leftover-box paste as tonight's job. That is join leftover-box columns side by side.
Skip leftover-box tr as tonight's job. That is change leftover-box characters.
Skip leftover-box timeout as tonight's job. That is stop a leftover-box command after a few seconds.
Skip leftover-box time as tonight's job. That is see how long a leftover-box command took.
Skip leftover-box date as tonight's job. That is see what time the leftover box thinks it is.
Skip leftover-box cal as tonight's job. That is see leftover-box month on a leftover-box calendar.
Skip leftover-box pwd as tonight's job. That is see which leftover-box folder you are in.
Skip leftover-box screen, leftover-box tmux, leftover-box script, leftover-box mesg, leftover-box wall, and leftover-box write as tonight's leftover-box job.
Skip leftover-box password login off as tonight. That is turn off leftover-box password login once the key works.
Skip leftover-box zip, tar, gzip, unzip, leftover-box du, leftover-box ping, and leftover-box curl as tonight's job. Those leftover-box pages already exist.
Skip htop, top, Grafana, a monitoring box, and a NAS. Skip leftover-box screen, leftover-box tmux, leftover-box script, leftover-box mesg, leftover-box wall, leftover-box write, nohup, ps, kill, kill -9, jobs, and pkill as tonight.
Skip leftover-box files under /etc, leftover-box whole leftover-box /, SSH folders, leftover-box /dev as a leftover-box dump, other disks, USB sticks, and /srv as tonight's lesson. Practice only in home. Shuf does not need leftover-box /etc or leftover-box / as leftover-box a leftover-box dump on night one.
What this is not
This is not leftover-box seq as leftover-box the leftover-box job. Seq prints leftover-box a leftover-box number leftover-box list leftover-box in leftover-box order. That is print a leftover-box number list. Tonight leftover-box uses leftover-box seq only leftover-box as leftover-box input leftover-box to leftover-box shuf. It is not leftover-box yes. Yes repeats leftover-box a leftover-box line. That is repeat a leftover-box line until you stop. It is not leftover-box echo. Echo prints leftover-box words you type once. That is put a short line into a leftover-box file. It is not leftover-box sort. Sort leftover-box orders. Shuf leftover-box mixes. That is put leftover-box lines in order. It is not leftover-box tac. Tac leftover-box reverses leftover-box lines leftover-box last-first. That is reverse leftover-box lines. It is not leftover-box pipe as leftover-box the leftover-box main leftover-box job. That is send leftover-box output into another command. It is not leftover-box uniq. That is drop leftover-box duplicate lines. It is not leftover-box nl. That is number leftover-box lines. It is not leftover-box clear. That is clear the leftover-box window. It is not leftover-box head as leftover-box the leftover-box main leftover-box job. That is see the start of a leftover-box file. It is not leftover-box watch. That is see leftover-box change without typing again. It is not leftover-box tput. That is see leftover-box terminal columns and colors. It is not leftover-box reset. That is fix a garbled leftover-box terminal. It is not leftover-box stty size. That is see leftover-box window size. It is not leftover-box tty. That is see leftover-box terminal name. It is not leftover-box less. That is read a leftover-box file one screen at a time. It is not leftover-box fold. That is wrap leftover-box long lines. It is not leftover-box wc. That is see how long a leftover-box file is. It is not leftover-box cut. That is pull one leftover-box column. It is not leftover-box paste. That is join leftover-box columns side by side. It is not leftover-box tr. That is change leftover-box characters. It is not leftover-box timeout. That is stop a leftover-box command after a few seconds. It is not leftover-box time. That is see how long a leftover-box command took. It is not leftover-box date. That is see what time the leftover box thinks it is. It is not leftover-box cal. That is see leftover-box month on a leftover-box calendar. It is not leftover-box password login off. That is turn off leftover-box password login once the key works. It is not leftover-box screen, leftover-box tmux, leftover-box script, leftover-box mesg, leftover-box wall, or leftover-box write as the leftover-box job. It is not leftover-box huge leftover-box ranges as leftover-box the leftover-box job. It is not leftover-box shuf leftover-box piped leftover-box into leftover-box rm. It is not a careful leftover-box delete. That is delete a leftover-box file carefully. It is not leftover-box extra leftover-box system software, leftover-box YubiKey, leftover-box camera, a monitoring app, htop, Grafana, or a NAS. It is not leftover-box /etc or leftover-box whole leftover-box /. It is not opening SSH to the internet so you can leftover-box mix leftover-box lines from a coffee shop. That is keep the leftover box on the house network. Do not forward port 22.
What next
Need leftover-box last-first leftover-box lines? Reverse leftover-box lines. Need leftover-box number leftover-box list leftover-box in leftover-box order? Print a leftover-box number list. Need leftover-box repeating leftover-box line? Repeat a leftover-box line until you stop. Need leftover-box lines leftover-box IN leftover-box order? Put leftover-box lines in order (sort leftover-box orders; leftover-box shuf leftover-box mixes). Need leftover-box words you type once? Put a short line into a leftover-box file. Need leftover-box send leftover-box as leftover-box the leftover-box lesson? Send leftover-box output into another command. Need leftover-box numbers leftover-box on leftover-box existing leftover-box lines? Number leftover-box lines. Need leftover-box practice files gone? Delete a leftover-box file carefully. When key login is boring on every computer you use, turn off leftover-box password login once the key works. Keep SSH on the house network: keep the leftover box on the house network. Do not forward port 22.
Skip
- Skip if SSH still fails. Finish SSH from the couch first.
- Skip leftover-box huge leftover-box ranges as leftover-box tonight's leftover-box job. Night one is leftover-box five leftover-box numbers.
- Skip leftover-box
shufleftover-box piped leftover-box into leftover-boxrmas leftover-box tonight's leftover-box job. Shuf leftover-box mixes leftover-box lines. Do not leftover-box mix leftover-box delete leftover-box into leftover-box this leftover-box drill. - Skip leftover-box
seqas tonight's job. Seq prints leftover-box a leftover-box number leftover-box list leftover-box in leftover-box order: print a leftover-box number list. Tonight leftover-box uses leftover-boxseqonly leftover-box as leftover-box input leftover-box to leftover-boxshuf. - Skip leftover-box
yesas tonight's job. Yes repeats leftover-box a leftover-box line: repeat a leftover-box line until you stop. - Skip leftover-box
echoas tonight's job. Echo prints leftover-box words you type once: put a short line into a leftover-box file. - Skip leftover-box
sortas tonight's job. Sort leftover-box orders. Shuf leftover-box mixes: put leftover-box lines in order. - Skip leftover-box
tacas tonight's job. Tac leftover-box reverses leftover-box lines leftover-box last-first: reverse leftover-box lines. Shuf leftover-box mixes leftover-box at leftover-box random. Tac leftover-box reverses leftover-box a leftover-box fixed leftover-box order. - Skip leftover-box pipe as leftover-box the leftover-box main leftover-box job. Pipe leftover-box is leftover-box only leftover-box the leftover-box send: send leftover-box output into another command.
- Skip leftover-box
uniqas tonight's job. That is drop leftover-box duplicate lines. - Skip leftover-box
nlas tonight's job. That is number leftover-box lines. - Skip leftover-box
clearas tonight's job. That is clear the leftover-box window. - Skip leftover-box
watchas tonight's job. That is see leftover-box change without typing again. - Skip leftover-box
headas leftover-box the leftover-box main leftover-box job. That is see the start of a leftover-box file. - Skip leftover-box
tputas tonight's job. That is see leftover-box terminal columns and colors. - Skip leftover-box
resetas tonight's job. That is fix a garbled leftover-box terminal. - Skip leftover-box
sttyas tonight's job. That is see leftover-box window size. - Skip leftover-box
ttyas tonight's job. That is see leftover-box terminal name. - Skip leftover-box
lessas tonight's job. That is read a leftover-box file one screen at a time. - Skip leftover-box
foldas tonight's job. That is wrap leftover-box long lines. - Skip leftover-box
wcas tonight's job. That is see how long a leftover-box file is. - Skip leftover-box
cutas tonight's job. That is pull one leftover-box column. - Skip leftover-box
pasteas tonight's job. That is join leftover-box columns side by side. - Skip leftover-box
tras tonight's job. That is change leftover-box characters. - Skip leftover-box
timeoutas tonight's job. That is stop a leftover-box command after a few seconds. - Skip leftover-box
timeas tonight's job. That is see how long a leftover-box command took. - Skip leftover-box
dateas tonight's job. That is see what time the leftover box thinks it is. - Skip leftover-box
calas tonight's job. That is see leftover-box month on a leftover-box calendar. - Skip leftover-box
pwdas tonight's job. That is see which leftover-box folder you are in. - Skip leftover-box
screen, leftover-boxtmux, leftover-boxscript, leftover-boxmesg, leftover-boxwall, and leftover-boxwriteas tonight's leftover-box job. - Skip leftover-box password login off as tonight. That is turn off leftover-box password login once the key works.
- Skip leftover-box zip, tar, gzip, unzip, leftover-box
du, leftover-box ping, and leftover-box curl as tonight's job. - Skip htop, top, Grafana, a monitoring box, and a NAS.
- Skip leftover-box files under
/etc, leftover-box whole leftover-box/, SSH folders, leftover-box/devas a leftover-box dump, other disks, USB sticks, and/srvas tonight's lesson. Practice only in home. Shuf does not need leftover-box/etcor leftover-box whole leftover-box/as leftover-box a leftover-box dump on night one. - Skip
rm -rf. Careful leftover-box delete only: delete a leftover-box file carefully. - Skip opening SSH to the internet so you can leftover-box mix leftover-box lines from a coffee shop. That is keep the leftover box on the house network. Do not forward port 22.
Sources
Debian: shuf(1). Ubuntu: shuf(1). Official pages only. For leftover-box repeating leftover-box line, see repeat a leftover-box line until you stop. For leftover-box number leftover-box list leftover-box in leftover-box order, see print a leftover-box number list. For leftover-box lines leftover-box IN leftover-box order, see put leftover-box lines in order. For leftover-box send, see send leftover-box output into another command. For the login, see SSH from the couch.