Command Crate

pkg query -e '%#r = 0' '%n-%v'

Lists packages nothing depends on

goaccess *.log --log-format='%C|%s|%x|%b|%^|%h|%R|%U|%^|%u|%^|%^' --date-format='%*' --time-format='%*' --enable-panel=REFERRERS

Analyzes Bunny CDN logs

find . -type f \( -perm -100 -o -perm -010 -o -perm -001 \) -print

Lists executable files

ffmpeg -nostats -i tetrakolius_-_odlazak_remastered.flac -af astats=metadata=0 -f null - 2>&1 | grep "Bit depth"

Shows real bit depth of audio

grep -E '^he_' /var/run/hostapd-phy*.conf | grep -v mu_edca

Shows Wi-Fi 6 settings

iw phy1 info | grep -A 10 'valid interface combinations'

Shows how many APs the radio supports

iw dev phy1-ap0 station dump | grep -c Station

Counts Wi-Fi clients

iw dev phy1-ap0 station dump | grep -E 'Station|signal:|tx bitrate|rx bitrate'

Shows Wi-Fi clients' signal and rates

iw dev phy1-ap0 survey dump | grep -A7 'in use'

Shows channel noise and busy time

iwinfo phy1-ap0 info | grep -E 'Channel|Tx-Power'

Shows Wi-Fi channel and transmit power

magick pokloni-website-card_1200x600.png -resize "1200x630^" -gravity center -extent 1200x630 pokloni-website-card_1200x600_fixed.png

Resizes and crops to exactly 1200x630

python3 -c "import re,sys,pathlib;p=re.compile(r'[\U0001f300-\U0001f9ff\U00002702-\U000027b0\U0000fe00-\U0000fe0f\U0000200b-\U0000200f\U0000200d]');[print(f'{f}:{i+1}: {l.rstrip()[:80]}') for f in pathlib.Path(sys.argv[1]).rglob('*') if f.suffix in ('.html','.md','.txt') for i,l in enumerate(f.read_text('utf-8').splitlines()) if p.search(l)]" ./

Finds emoji and invisible characters in text files

pkg info -r ImageMagick7

Lists packages that depend on a package

gzip --best -k file.svg && mv file.svg.gz file.svgz

Compresses SVG to SVGZ

dnf repoquery --installed --whatrequires ImageMagick7

Lists packages that depend on a package

magick main_screen.png -background none -size 20x1 xc:none results.png +append kalkulator-prostih-brojeva-app-pregled.png

Joins images side by side with a gap

awk -F'[<>]' '/<loc>/ {print $3}' sitemap.xml

Extracts URLs from a sitemap

sed -n 's/.*<loc>\(.*\)<\/loc>.*/\1/p' sitemap.xml

Extracts URLs from a sitemap

top -o res

Sorts processes by real memory use

magick gshock-gw-m5610u-1b.png -fill "#fbfbfe" -opaque "#e6f1f5" -fill "#1c1b22" -opaque "#203a43" gshock-gw-m5610u-1b_darkgrey.png

Swaps two colors in an image

printf 'dev.hwpstate_intel.0.epp=100\ndev.hwpstate_intel.1.epp=100\ndev.hwpstate_intel.2.epp=100\ndev.hwpstate_intel.3.epp=100\n' | sudo tee -a /etc/sysctl.conf && sudo sysrc powerd_enable='NO'

Makes Intel powersave permanent, disables powerd

sysctl dev.cpu.0.freq_levels

Single frequency level = use hwpstate_intel, not powerd

sysctl dev.hwpstate_intel.0.epp=100

Sets Intel CPU to powersave (0 = performance)

sysctl dev.cpu.0.freq dev.cpu.0.freq_levels dev.cpu.0.cx_supported dev.cpu.0.cx_lowest

Shows CPU frequency and sleep states

magick input.xcf -flatten -resize 3000x3000 -strip -quality 92 output.jpg

Converts GIMP XCF to JPEG

magick rss-icon.png -quality 75 -define webp:method=6 -define webp:pass=10 rss-icon.webp

Converts PNG to small WebP

magick -background none -density 648 favicon.svg rss-icon.png

Converts SVG to sharp PNG (density = target/source x 72)

ffmpeg -i tetrakolius_-_tetrahedron.flac -filter_complex "[0:a]avectorscope=s=640x640:rate=25:zoom=1.5:draw=line" -y tetrahedron_phase.mp4

Makes a stereo phase scope video

ffmpeg -i tetrakolius_-_tetrahedron.flac -filter_complex "pan=mono|c0=c0-c1" -y tetrahedron_side_signal.wav

Extracts the side signal (L minus R)

adb push ./local_file /sdcard/Download/

Copies a file to Android fast

ffmpeg -i input.wav -af "pan=stereo|c0=c0|c1=-1*c1" phase_flip.wav

Inverts the right channel's phase

ffmpeg -i input.wav -af "pan=stereo|c0=c0|c1=c0" vangogh.wav

Copies left channel to both sides

ffmpeg -i input.wav -codec:a libmp3lame -q:a 0 output.mp3

Converts to V0 MP3

ffmpeg -i input.wav -codec:a libmp3lame -b:a 320k output.mp3

Converts to 320k MP3

magick input.png -resize 1000x1000 -quality 90 output.jpeg

Resizes to fit 1000 px, saves as JPEG

magick input.png -define jpeg:extent=1.8MB output.jpeg

Converts to JPEG under 1.8 MB

magick cover.png \( -background none -size 200x200 logo.svg \) -gravity SouthEast -geometry +100+100 -composite output.png

Puts a logo in the bottom-right corner

metaflac --remove --block-type=PICTURE file.flac && metaflac --import-picture-from="cover.jpg" file.flac

Replaces FLAC cover art

ffmpeg -i input.flac -af loudnorm=I=-12:TP=-2:LRA=7:print_format=summary -c:a flac -sample_fmt s32 -ar 48000 output.flac

Masters to -12 LUFS, -2 dBTP, 24-bit 48 kHz

etcupdate diff | less

Shows your changes to /etc vs stock

bastille cmd ALL ping -c 1 8.8.8.8

Tests internet access from all jails

service pf reload

Reloads PF rules

pfctl -nf /etc/pf.conf

Checks pf.conf for errors without loading

fsck -t ufs -f -y /dev/da0p1

Forces a full UFS check and repair

tunefs -n enable /dev/da0p1

Enables UFS Soft Updates

tunefs -t enable /dev/da0p1

Enables UFS TRIM

tunefs -j enable /dev/da0p1

Enables UFS journaling (SU+J)

tunefs -p /dev/da0p1

Shows UFS settings

tunefs -m 0 /dev/da0p1

Frees UFS reserved space (~8%)

fsck -t ufs -y /dev/da0p1

Checks and repairs a UFS partition

e2fsck -f /dev/da0p1

Checks and repairs an ext partition

tune2fs -L "NEW_LABEL" /dev/da0p1

Renames an ext partition

sysupgrade -b /tmp/backup.tar.gz

Backs up router config

block info

Lists block devices with UUIDs and labels

whereis -b ansible

Finds a program's binary

/usr/libexec/locate.updatedb

Updates the locate database

procstat -f $(pgrep nginx)

Lists a process's open files

pfctl -s info

Shows PF firewall status

service -e

Lists enabled services

sockstat -4l

Lists listening IPv4 sockets with processes

kldstat -v

Lists loaded kernel modules

pciconf -lv

Lists PCI devices with drivers

service powerd status

Checks if powerd is running

sysctl dev.cpu.0.cx_usage

Shows CPU sleep state usage

sysctl dev.cpu.0.freq_levels

Lists CPU frequency steps

sysctl dev.cpu.0.freq

Shows current CPU frequency

sysctl dev.cpu | grep temperature

Shows CPU temperatures (needs coretemp)

top -P -s 1

Shows per-CPU usage, refreshing every second

bastille rdr target_jail tcp 8080 80

Forwards host port 8080 to port 80 in a jail

bastille stop target_jail

Stops a jail

bastille cmd ALL echo 'Hello World'

Runs a command in all jails

bastille console hlab-ansible-server

Opens a shell in a jail

bastille list

Lists jails

pkg audit -F

Checks packages for known vulnerabilities

pkg info -as | sort -hk 2

Lists packages by size

pkg query -e '%a = 0' '%n-%v'

Lists packages you installed explicitly

bectl create -r pre-update-backup

Creates a boot environment before an update

bectl list

Lists boot environments

zpool scrub zroot

Starts a ZFS scrub

zpool status -v zroot

Shows pool health, errors and scrub progress

zpool list -v

Shows pool capacity per disk

zfs list -o space

Shows ZFS space usage incl. snapshots

glabel status

Lists labels and their devices

geom disk list

Lists disks with details

tune2fs -L "DATA_VAULT" /dev/da0p1

Labels an ext partition

tune2fs -O ^has_journal /dev/da0p1

Removes the journal from ext4

mount -o async,noatime /dev/ufs/DATA-DISK /media/DATA-DISK

Mounts a UFS drive for fast writes (unmount before unplugging)

tunefs -L "DATA-DISK" /dev/da0p1

Labels a UFS partition

rsync -avhW --no-compress --info=progress2 /source/ /media/DATA-DISK/

Fast local copy to a USB drive

dd if=/dev/zero of=/media/DATA-DISK/speedtest.img bs=1M count=1000 conv=fsync status=progress

Measures drive write speed (delete speedtest.img after)

cmp ./Samsung_SSD_990_PRO_8B2QJXD7.iso /dev/sdb

Verifies a written ISO ('EOF on iso' = OK)

echo "${SRANDOM}"

Prints a secure random number (bash 5.1+)

assoc .txt=txtfile

Associates .txt with text files

dism /online /export-driver /destination:C:\BackupDrivers

Exports all drivers to a folder

netstat -ano | findstr LISTENING

Lists listening ports with PIDs

taskkill /F /FI "STATUS eq NOT RESPONDING"

Kills all frozen apps

wmic path softwarelicensingservice get OA3xOriginalProductKey

Shows the OEM product key from firmware (wmic is deprecated)

python3 -m http.server 8000

Serves the current directory on port 8000 (whole network can see it)

powercfg /batteryreport

Creates a battery health report

netsh wlan show profile name="SSID" key=clear

Shows a saved Wi-Fi password

ipconfig /flushdns

Clears the DNS cache

defrag /c /h /v /b /o

Optimizes all drives (defrag or TRIM)

defrag /c /h /v /a

Analyzes fragmentation on all drives

sfc /scannow

Repairs Windows system files

cleanmgr /sageset:1 cleanmgr /sagerun:1

Configures and runs Disk Cleanup

chkdsk /f /r

Fixes disk errors and bad sectors (slow)

chkdsk /scan

Scans a disk for errors without fixing

winget repair [package-name or package-ID]

Repairs a program

winget upgrade --all

Updates all programs

winget list

Lists installed programs

dnf --assumeno install package1

Previews an install without doing it

apt autoremove --purge

Removes unneeded packages and their config

apt -s install package1 package2

Simulates an install

apt remove --purge package1

Removes a package and its config

apt install --no-install-recommends --no-install-suggests package1 package2

Installs packages without recommends or suggests

MP4Box -info $VIDEO.mp4 2>&1 | grep RFC6381 | awk '{print $4}' | paste -sd , -

Gets codec strings for an HTML5 video tag

find ./.artwork/jpeg/ -type f \( -name "*.jpeg" -o -name "*.jpg" \) ! -name "*_optimized.jpeg" -exec bash -c 'magick -strip -quality 88 -verbose -limit thread 0 "$0" sixel:- > "${0%.*}.six"' '{}' \;

Converts JPEGs to sixel for terminal display

find . -type f -wholename '*.flac' -exec bash -c 'ffmpeg -hide_banner -loglevel error -nostats -y -i "$(eval "echo .meta/artwork/*video_cover_l.jpeg")" -i "${0}" -metadata title="$(metaflac --show-tag=TITLE "${0}" | cut -c7-)" -metadata artist="$(metaflac --show-tag=ARTIST "${0}" | cut -c8-)" -metadata album="$(metaflac --show-tag=ALBUM "${0}" | cut -c7-)" -metadata genre="$(metaflac --show-tag=GENRE "${0}" | cut -c7-)" -metadata encoded_by="FFmpeg" -q:v 8 -codec:v libvpx-vp9 -lossless 1 -preset slow -quality good -speed 0 -deadline best -codec:a libopus -b:a 160k -vbr on -compression_level 10 -pix_fmt yuv420p -threads 0 "./${0%.*}_vp9_opus_1080p.webm"' '{}' \;

Turns FLACs into WebM videos with cover art

git ls-files . --exclude-standard --others

Lists untracked files

git ls-files . --ignored --exclude-standard --others

Lists ignored files

Get-ChildItem -Path Cert:\CurrentUser\My | Select-Object -Property Subject, NotAfter

Lists your certificates with expiry dates

git show b523b86 | grep -i 'JS'

Shows lines of a commit matching a word

git log -S "specific_variable_name"

Finds commits that added or removed a string

lsof -p 1234

Lists files a process has open

dnf provides /usr/bin/ssh

Finds which package provides a file

dig +trace google.com

Follows DNS resolution from the root servers

openssl dgst -sha256 myfile

Shows a file's SHA256

truncate -s 5G large_dummy_file.img

Creates an empty 5 GB sparse file instantly

git bisect start BAD_COMMIT GOOD_COMMIT

Starts a binary search for the commit that broke something

iostat -dx 2

Shows disk I/O stats every 2 seconds

nmap -p 22 --open 192.168.1.0/24

Finds hosts with SSH open

podman inspect bfd59994e8f2

Shows container details

journalctl --unit=nginx.service --follow --output=json-pretty

Follows nginx logs as JSON

ss -tlpn 'sport = :8080'

Shows what listens on port 8080

php phpstan.phar --memory-limit=4096M analyse --level max ~/index.php

Checks a PHP file with PHPStan at max level

ionice -c 3 python3 mistat.py generate-all

Runs a script with idle disk priority

diff mistat_v3.py mistat_v4.py

Shows differences between two files

date -d '2025-06-13 08:22:00 UTC' +%s

Converts a date to a UNIX timestamp (GNU date)

find . -type f -wholename '*.flac' -exec bash -c 'DELAY_COMPENSATION=0.2; SMOOTHING_PX=2; FLAC_FILE="$0"; COVER_PATH=".meta/artwork/$(basename "${FLAC_FILE}" ".flac")-video_cover_l.jpeg"; BRIGHTNESS=$(magick "$COVER_PATH" -colorspace Gray -format "%[mean]" info:); VISUALISER_COLOR="white"; BRIGHTNESS_THRESHOLD=35000; if (( $(echo "$BRIGHTNESS > $BRIGHTNESS_THRESHOLD" | bc -l) )); then VISUALISER_COLOR="black"; fi; GEQ_FORMAT="r=r(X,Y):g=g(X,Y):b=b(X,Y):a=st(0,H/2*sin(X/W*PI));st(1,abs(Y-H/2));if(gt(ld(1),ld(0)),0,if(lt(ld(1),ld(0)-%s),alpha(X,Y),alpha(X,Y)*(ld(0)-ld(1))/%s))"; GEQ_FINAL=$(printf "$GEQ_FORMAT" "$SMOOTHING_PX" "$SMOOTHING_PX"); echo "Processing ${FLAC_FILE}. Cover brightness: $BRIGHTNESS. Using visualiser color: $VISUALISER_COLOR. Applying ${DELAY_COMPENSATION}s delay compensation. Applying ${SMOOTHING_PX}px edge smoothing."; ffmpeg -hide_banner -loglevel error -nostats -y -framerate 24 -i "$COVER_PATH" -i "$FLAC_FILE" -filter_complex "[0:v]scale=1920:1080,setsar=1[bg]; [1:a]asplit[a_out][a_viz]; [a_viz]asetpts=PTS-${DELAY_COMPENSATION}/TB[a_viz_shifted]; [a_viz_shifted]showwaves=s=1400x140:mode=cline:colors=${VISUALISER_COLOR}:draw=full:rate=24,format=rgba[waves_hr]; [waves_hr]scale=700:70:eval=init:flags=lanczos[waves]; [waves]geq='\''"$GEQ_FINAL"'\''[waves_faded]; [waves_faded]colorchannelmixer=aa=0.3[waves_transparent]; [bg][waves_transparent]overlay=(W-w)/2:910[outv]" -map "[outv]" -map "[a_out]" -metadata title="$(metaflac --show-tag=TITLE "${FLAC_FILE}" | cut -c7-)" -metadata artist="$(metaflac --show-tag=ARTIST "${FLAC_FILE}" | cut -c8-)" -metadata album="$(metaflac --show-tag=ALBUM "${FLAC_FILE}" | cut -c7-)" -metadata genre="$(metaflac --show-tag=GENRE "${FLAC_FILE}" | cut -c7-)" -metadata encoded_by="FFmpeg" -crf 45 -b:v 0 -codec:v libvpx-vp9 -cpu-used 0 -row-mt 1 -auto-alt-ref 1 -lag-in-frames 25 -g 250 -codec:a libopus -b:a 160k -vbr on -compression_level 10 -frame_duration 60 -application audio -pix_fmt yuv420p -threads 0 "./${FLAC_FILE%.*}_vp9_opus_visualiser_1080p.webm"' '{}' \;

Turns FLACs into WebM videos with cover art and a waveform

cuebreakpoints "tetrakolius - The Best Of.cue" | shnsplit -o flac -f "tetrakolius - The Best Of.cue" -t "%n-%t" "tetrakolius - The Best Of.flac"

Splits a FLAC into tracks using a CUE sheet

for f in *.wav; do ffmpeg -i "$f" -hide_banner -loglevel error -nostats -vn -ac 1 -c:a libopus -b:a 24k -compression_level 10 -application voip -map_metadata 0 -metadata composer="" -metadata ENCODED-BY="" -metadata comment="" -metadata COMM="" -metadata encoded_by="FFmpeg$(ffmpeg -version | head -n1 | awk '{print $3}')" "${f%.wav}.opus"; done

Converts WAVs to mono 24k Opus for podcasts

for f in *.wav; do ffmpeg -i "$f" -hide_banner -loglevel error -nostats -ac 1 -c:a libmp3lame -q:a 8 -joint_stereo 1 -compression_level 9 -map_metadata 0 -metadata composer="" -metadata ENCODED-BY="" -metadata comment="" -metadata encoded_by="FFmpeg$(ffmpeg -version | head -n1 | awk '{print $3}')" -id3v2_version 3 "${f%.wav}.mp3"; done

Converts WAVs to mono speech MP3 for podcasts

for f in *.flac; do ffmpeg -i "$f" -ab 320k -map_metadata 0 -id3v2_version 3 "${f%.flac}.mp3"; done

Converts FLACs to 320k MP3

find . -type f -perm -o+w -ls

Finds world-writable files

ip addr show | grep -Eo 'inet (addr:)?([0-9]{1,3}\.){3}[0-9]{1,3}' | grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}'

Shows IPv4 addresses

systemctl list-timers --all

Lists systemd timers

find . -type f -size +100M -print0 | xargs -0 ls -lh | sort -k5 -h

Lists files over 100 MB by size

lsof -i TCP:80

Shows what uses TCP port 80

ps -eo pid,comm,%mem,%cpu --sort=-%mem | head

Shows processes sorted by memory

find . -type f -printf '%T+\t%p\n' | sort | head -n 1

Shows the oldest file

journalctl --disk-usage

Shows journal disk usage

ps aux | awk '{print $1, $2, $3, $4, $11}' | sort -k 4 -rn | head -n 10

Shows top 10 processes by memory

echo 'Secret' > ~/.secret_file; history -d $((HISTCMD-1))

Writes a secret without keeping it in bash history

find "${HOME}/cats" \( -name "*.png" -o -name "*.gif" \) -exec touch -t "$(date +%Y%m%d)0100" {} \;

Sets the date of PNG and GIF files to today 01:00

for d in */; do XZ_OPT="-9e" tar -cvJf "${d%/}.tar.xz" "$d"; done

Archives each directory into its own .tar.xz

for f in *.mp3; do echo "$f: $(soxi -B "$f")"; done

Shows the bitrate of each MP3

find . -name "*.eno" -print0 | tar -czvf eno-backup-$(date '+%Y-%m-%d_%H%M%S').tar.gz --null -T -

Archives all .eno files with a dated name

ping google.com | awk '{ print strftime("[%Y-%m-%d %H:%M:%S]"), $0; fflush() }'

Adds timestamps to ping output (gawk)

ping google.com | ts '[%Y-%m-%d %H:%M:%S]'

Adds timestamps to ping output (moreutils)

flatpak override --reset com.bitwig.BitwigStudio

Resets a Flatpak's permission overrides

flatpak override --show com.bitwig.BitwigStudio

Shows a Flatpak's permission overrides

xdg-settings get default-web-browser

Shows the default browser

flatpak mask --remove com.bitwig.BitwigStudio

Unblocks updates for a Flatpak

flatpak mask

Lists masked Flatpaks

flatpak mask com.bitwig.BitwigStudio

Blocks updates for a Flatpak

flatpak update --commit=d46e23d2d45efb8f9b5e38d60abbbeb17cce6ee3d8143918fa4d7f0708b4eee7 com.bitwig.BitwigStudio

Installs a specific Flatpak commit (downgrade)

flatpak remote-info --log flathub com.bitwig.BitwigStudio

Shows a Flatpak's commit history

SELECT user,host FROM mysql.user;

Lists MySQL users

SHOW GRANTS FOR 'ABC'@'%';

Shows a MySQL user's privileges

find . -maxdepth 1 -type f -name "*.flac" -exec bash -c 'sha256sum "$1" | sed "s|./||" > "$1.sha256"' _ {} \;

Writes a .sha256 file next to each FLAC

Get-Process notepad* | Stop-Process -Force

Kills all Notepad windows

taskkill /F /IM ms-teams.exe

Kills Teams

tasklist | findstr /i "teams.exe"

Checks if Teams is running

systeminfo | find /i "original"

Shows the Windows install date

(Get-Item "C:\Windows\system.ini").CreationTime

Shows the Windows install date

"{0:N2} MB" -f ((Get-ChildItem -Recurse -File | Measure-Object -Property Length -Sum).Sum / 1MB)

Shows total folder size in MB

Get-ChildItem -File | ForEach-Object { $hash = Get-FileHash $_.FullName -Algorithm SHA256 "$($hash.Hash) $($_.FullName)" }

Lists SHA256 hashes of all files

1..4 | ForEach-Object { -join ((65..90) + (97..122) + (48..57) | Get-Random -Count 10 | % {[char]$_}) }

Generates 4 random 10-character strings

php -S 127.0.0.1:8080 -t .

Serves the current directory with PHP on localhost:8080

for file in *.heic; do magick "$file" "${file%.heic}.jpeg"; done

Converts HEIC photos to JPEG

git remote rename origin codeberg

Renames a remote

git remote -v

Lists remotes

git diff --staged

Shows staged changes

for f in *.flac; do echo "$f"; sox "$f" -n stat; done

Shows audio stats for each FLAC

ffmpeg -i INPUT.flac -af loudnorm=I=${TARGET_INTEGRATED_LOUDNESS}:TP=${TARGET_TRUE_PEAK}:LRA=${TARGET_LOUDNESS_RANGE}:measured_I=${MEASURED_INPUT_INTEGRATED_LOUDNESS}:measured_TP=${MEASURED_INPUT_TRUE_PEAK}:measured_LRA=${MEASURED_INPUT_LOUDNESS_RANGE}:measured_thresh=${MEASURED_INPUT_THRESHOLD}:offset=${TARGET_NORMALIZATION_OFFSET}:linear=true OUTPUT.flac

Normalizes loudness, second pass (add -ar 48000; output defaults to 192 kHz)

for f in *.flac; do echo "$f"; ffmpeg -hide_banner -nostats -i "$f" -af loudnorm=print_format=summary -f null -; done

Measures loudness of each FLAC

free -t -m

Shows memory usage in MB

free -t | tail -n+2 | awk '{($2>0) ? p=$3/$2*100.0 : p=0.0; print "Used " $1 "\t" p "%"}'

Shows memory usage in percent

grep -E --color 'Mem|Cache|Swap' /proc/meminfo

Shows memory and swap lines

dconf dump / >~/.config/dconf/user.conf dconf load / <~/.config/dconf/user.conf

Backs up and restores GNOME settings

for f in *.flac; do sox -S "${f}" -r 44100 -b 16 "${f%.*}"_16bit_44100.flac; done

Converts FLACs to 16-bit 44.1 kHz

for f in *; do ffmpeg -i "$f" -map 0 -map -0:s -codec copy "$f.mkv"; done

Removes subtitles from videos into MKV

for f in *; do ffmpeg -i "$f" -f mp4 -c:v libx265 -preset ultrafast -crf 24 -acodec aac "${f%.*}"_x265.mp4; done

Converts videos to H.265 MP4 (fast, larger files)

gpgconf --list-dirs

Shows GPG directories

gpg --list-keys

Lists GPG keys

gpgconf --kill gpg-agent

Restarts gpg-agent

git commit --amend

Edits the last commit

git config --global tag.gpgSign true

Signs all tags

git config --global commit.gpgsign true

Signs all commits

git config --global user.signingkey ABCBCA

Sets the GPG key for signing

git log --all --pretty=format:"%h - %an <%ae>"

Lists commits with hash and author

ledger reg Expenses -S amount

Lists expenses sorted by amount

ledger bal ^Expenses ^Income --invert

Shows expenses and income, sign inverted

ledger -M register Assets -X EUR -n --no-rounding

Shows monthly asset totals in EUR

ledger reg -b 09/01 -e 12/01 --subtotal

Shows transactions from Sep 1 to Dec 1, subtotalled

ledger bal Expenses --flat -S -amount

Shows expenses as a flat list, largest first

ledger register Expenses

Lists expense transactions

ledger balance Assets --collapse

Shows asset balances, collapsed

ledger balance income expenses --period "this month"

Shows this month's income and expenses

#!/bin/sh # Simple logging script with date filtering, colorizing, and Todo.txt compatibility. TIMESTAMP=$(date "+%Y-%m-%d [%H:%M:%S]") LOG="${HOME}/.jnrl.log" CONTEXT="${CONTEXT:-20}" TODOTXT_TAG='+jnrl' # Ensure the log file exists touch "$LOG" # Colorize timestamp matches in log output grep_coloring() { grep --color=always -E "(\[[0-9]{2}:[0-9]{2}:[0-9]{2}|\])" "$@" } # Handle date range filtering based on OS type (BSD vs GNU date) if [ "$1" = "-d" ] && [ "$2" -ge 0 ] 2>/dev/null; then DATE_RANGE=$(date --date="$2 day ago" "+%Y-%m-%d" 2>/dev/null || date -v "-$2d" "+%Y-%m-%d") grep "$DATE_RANGE" "$LOG" | grep_coloring elif [ -z "$*" ]; then # Show last N lines if no arguments are provided tail -n "$CONTEXT" "$LOG" | grep_coloring else # Log the message with timestamp and Todo.txt tag, escaping special characters echo "${TIMESTAMP} - $(printf '%q' "$*") $TODOTXT_TAG" >> "$LOG" fi

Journal script: logs notes with timestamps, filters by day

cat <<EOF (*- { $@ } //\ v_/_ EOF

Prints a Tux saying the arguments

pwgen -Bnyc 15 1

Generates a 15-character password

shuf -n 4 --random-source=/dev/urandom /usr/share/dict/words | paste -sd ' ' -

Generates a 4-word passphrase (xkcd 936)

openssl rand -base64 16

Generates a 24-character password

openssl rand -hex 15 | sha256sum | head -c15 | cut -b -15

Generates a 15-character hex password

gpg --gen-random --armor 1 15 | head -c15

Generates a 15-character password

#!/bin/bash PODCAST_DOWNLOAD_DIR="${HOME}/Ресурси/Преузимања/Podcasts" if [ -e "$PODCAST_DOWNLOAD_DIR" ] && [ ! -z "$(command -v ffmpeg)" ]; then find "$PODCAST_DOWNLOAD_DIR" -type f -name '*.mp3' -execdir bash -c ' PODCAST_FILE="$1" PODCAST_FILE_LENGTH_IN_SECONDS="1800" if [[ ! $PODCAST_FILE =~ ^[a-zA-Z0-9]{3}-[0-9]{2}- ]]; then random_filename_string=$(tr -dc "a-zA-Z0-9" < /dev/urandom | head -c 3) ffmpeg -i "$PODCAST_FILE" -c:a libmp3lame -q:a 6 -f segment -segment_time ${PODCAST_FILE_LENGTH_IN_SECONDS} -map 0:a -map_metadata -1 "${random_filename_string}-%02d-${PODCAST_FILE##*/}" && rm "$PODCAST_FILE" fi ' sh {} \; fi

Splits long podcast MP3s into 30-minute parts

cd "${BACKUP_DESTINATION}" && export XZ_DEFAULTS="-9 -T 0" && tar cJf "${BACKUP_FILENAME}.tar.xz" "$TARGET_PATH" 2>/dev/null && tar -tf "${BACKUP_FILENAME}.tar.xz" 2>/dev/null && sha256sum "${BACKUP_FILENAME}.tar.xz" > "${BACKUP_FILENAME}.tar.xz.sha256" && chown -R ${OWNER_USERNAME}:${OWNER_USERNAME} "${BACKUP_DESTINATION}/${BACKUP_FILENAME}.tar.xz"

Creates a compressed backup, verifies it, writes a checksum

if [ -z "$(pidof -x "$1")" ]; then "$1" & exit 0; else exit 1;fi

Starts a program only if it isn't already running

cat myfile.txt | tr -d '\n' | wc -c

Counts characters in a file without newlines

GOGC=10 hugo server --environment development --watch --disableFastRender --templateMetrics --templateMetricsHints --buildFuture --buildDrafts

Runs Hugo dev server with drafts and future posts

find . -type d -exec du -h --max-depth=1 {} + 2>/dev/null | sort -rh | head -n "10" | awk -v highlighter="\033[1;32m" -v reset="\033[0m" '{gsub(/[0-9,.]+[MGK]|^0[[:space:]]/, highlighter "&" reset); print}'

Lists the 10 largest directories, sizes highlighted

find . -type f -exec du -h {} + 2>/dev/null | sort -rh | head -n "10" | awk -v highlighter="\033[1;36m" -v reset="\033[0m" '{gsub(/[0-9,.]+[MGK]|^0[[:space:]]/, highlighter "&" reset); print}'

Lists the 10 largest files, sizes highlighted

find . -type f -name "*.txt" -exec wc -l {} +

Counts lines in all .txt files

cat /bin/ls | hexdump -C | less

Shows a binary as hex

SELECT random_article_id FROM random_articles WHERE date = DATE('now') LIMIT 1

Gets today's article ID

podman exec -d "$client_name" /bin/sh -c "if which apk > /dev/null; then /usr/bin/node_exporter; elif which apt-get > /dev/null; then /usr/bin/prometheus-node-exporter; fi"

Starts Node Exporter inside an Alpine or Debian container

podman exec -d "$client_name" sh -c "/usr/sbin/sshd -D -e"

Starts sshd inside a container

podman exec "$client_name" sh -c "pkill sshd"

Stops sshd inside a container

podman exec "$client_name" sed -i '/^#\?PubkeyAuthentication /c\PubkeyAuthentication yes' /etc/ssh/sshd_config

Enables SSH key login inside a container

podman machine set my-machine --cpus 4 --memory 4096

Changes a podman VM to 4 CPUs and 4 GB

podman machine init my-machine --cpus 2 --memory 2048

Creates a podman VM with 2 CPUs and 2 GB

podman container ls -a --filter name="$container" --format "{{.Names}}"

Shows a container's name if it exists

podman auto-update

Updates containers labelled for auto-update

podman image prune -a -f

Deletes all unused images

curl --silent -L "$download_url" -o "$filepath"

Downloads a file quietly, following redirects

git -C ~/my_project log --pretty=format:'%H' --max-count 5

Shows the last 5 commit hashes of a project

python -m http.server 8899 --bind 127.0.0.1

Serves the current directory on localhost:8899

git --no-pager show -s --format="%an <%ae>"

Shows author of the latest commit

journalctl --unit clamav-clamonacc --since today

Shows today's ClamAV on-access logs

find . -type f -exec du -h {} + | sort -r -h | head -n 10

Lists the 10 largest files

cmark --to html --validate-utf8 --unsafe

Converts Markdown to HTML (raw HTML allowed)

inxi -v 3 -F -B -z -c 7

Shows full system info with private data hidden

mpv --loop --audio-display=no

Loops a file in mpv without showing cover art

nano --autoindent --backup --boldtext --mouse --nonewlines --nowrap --nohelp --multibuffer --quickblank --smarthome --constantshow --linenumbers --tabstospaces -T 2 --indicator --backupdir="$HOME/.cache" some_file_i_wanna_create.txt

Opens nano with indent, line numbers, 2-space tabs and backups

w3m -no-cookie -no-graph -W

Starts w3m without cookies, plain ASCII

elinks -anonymous 1 -no-home 1 -no-connect 1

Starts ELinks without saving anything

curl -Is -H "Accept-Encoding: gzip,deflate,br" https://durad.xyz | grep -i "content-encoding"

Checks if a site serves compressed responses

netstat -tupan

Lists connections and listening ports with processes

ps aux | sort -nr -k 4 | head -5

Shows top 5 processes by memory

dumpe2fs -h /dev/root | grep -i created

Shows when the root filesystem was created (install date)

find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate

Finds duplicate files, comparing sizes first (faster)

find . ! -empty -type f -exec md5sum {} + | sort | uniq -w32 -dD

Finds duplicate files by checksum

udevadm control --reload-rules && udevadm trigger

Reloads udev rules and applies them

cryptsetup benchmark

Benchmarks disk encryption ciphers

cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 10 | head -n 4

Generates 4 random 10-character strings

journalctl -b2

Shows logs of boot #2 from the oldest (-b -1 = previous boot)

for file in *; do zip -r "${file%.*}.zip" "$file"; done

Zips each file or folder into its own archive

pactl set-sink-volume @DEFAULT_SINK@ +2%

Raises volume by 2%

smartctl -l selftest /dev/sdX

Shows SMART self-test results

smartctl -t short /dev/sdX

Starts a short SMART self-test

smartctl -a /dev/sdX

Shows SMART health of a disk

find $DIR_PATH -type f -exec chmod 644 {} \;

Sets all files to 644

find $DIR_PATH -type d -exec chmod 755 {} \;

Sets all directories to 755

for f in *.ass; do ffmpeg -i "$f" -c:s srt "${f%.*}".srt; done

Converts .ass subtitles to .srt

for f in *.flac; do sox -S "${f}" -r 44100 -b 16 ./resampled/"${f%.*}"_16bit_44100.flac; done

Converts FLACs to 16-bit 44.1 kHz into ./resampled

xsetroot -cursor_name left_ptr

Sets the default X11 cursor

iw list

Shows Wi-Fi hardware capabilities

for file in *.html; do printf "$file\t$(cat $file | wc -c | xargs printf "%'d\n")\t$(gzip -9c $file | wc -c | xargs printf "%'d\n")\t$(brotli -cZ $file | wc -c | xargs printf "%'d\n")\n"; done | tee

Compares raw, gzip and brotli sizes of HTML files

vboxsdl --startvm $VM_NAME

Starts a VirtualBox VM in a plain SDL window

vboxmanage modifyvm Debian5 --nic1 bridged --cableconnected1 on --bridgeadapter1 eth0

Bridges a VirtualBox VM's network to eth0

vboxmanage hostonlyif remove vboxnet0

Removes a VirtualBox host-only network

vboxmanage storagectl $VM_NAME --name "IDE Controller" --add ide --controller PIIX4

Adds an IDE controller to a VirtualBox VM

vboxmanage modifyvm $VM_NAME --memory 1024 --vram 128 --accelerate2dvideo on --accelerate3d off --audio alsa --cpuexecutioncap 85 --ostype WindowsXP

Sets VirtualBox VM memory, video and CPU options

vboxmanage createhd --filename $VM_HDD_PATH --size 35000 --variant fixed

Creates a fixed 35 GB VirtualBox disk

vboxmanage registervm $VM_PATH

Registers an existing VirtualBox VM

vboxmanage createvm --name "Debian" --ostype "Debian_64" --register

Creates a VirtualBox VM

stat -c %a .bashrc

Shows file permissions as a number (GNU stat)

rfkill unblock all

Unblocks Wi-Fi and Bluetooth

printf "file '%s'\n" input1.mp4 input2.mp4 > list.txt && ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4

Joins videos without re-encoding

/etc/init.d/alsa-utils reset 0

Resets ALSA sound settings

systemctl set-default graphical.target

Boots into the graphical desktop by default

flatpak remote-ls flathub | grep org.gtk.Gtk3theme

Lists GTK3 themes on Flathub

ausearch -c 'hl2_linux' --raw | audit2allow -M my-hl2linux

Builds an SELinux policy module from denials

grub2-mkconfig -o /boot/grub2/grub.cfg

Regenerates the GRUB config

sealert -a /var/log/audit/audit.log

Explains SELinux denials

fixfiles onboot

Relabels SELinux on next boot

journalctl --vacuum-time=2weeks

Deletes journal logs older than 2 weeks

dmesg | grep -i ahci

Shows AHCI messages from the kernel log

dd if=/dev/zero of=./largefile bs=7M count=256 conv=fsync

Measures disk write speed (delete largefile after)

restorecon -r -v /

Restores SELinux labels on the whole system

vnstat --add -i wlp6s0

Adds an interface to vnStat

vnstat --iflist

Lists interfaces vnStat can monitor

package-cleanup --oldkernels --count=5

Removes all but 5 kernels (legacy yum)

gsettings list-recursively | grep -i Epiphany

Lists GNOME Web settings

sed -i 's/^installonly_limit=.*/installonly_limit=4/' /etc/dnf/dnf.conf

Keeps at most 4 kernels

dnf remove $(dnf repoquery --installed --latest-limit=-2 -q)

Removes all but the 2 newest versions of multi-version packages

echo "never" > /sys/kernel/mm/transparent_hugepage/defrag

Disables transparent hugepage defrag

authconfig --disablefingerprint --update

Disables fingerprint login (legacy; use authselect)

tracker status

Shows Tracker indexing status (tracker3 on v3)

tracker daemon -t

Stops Tracker indexing (tracker3 on v3)

echo "blacklist firewire-core" >> /etc/modprobe.d/firewired.conf

Blocks the FireWire module from loading

SELECT * FROM categories ORDER BY name ASC;

Lists categories sorted by name

dnf grouplist -v

Lists DNF package groups

qemu-img create -f qcow2 -o preallocation=off <disk-name> <disk-size>

Creates a thin QCOW2 disk image

virsh pool-destroy default

Stops a libvirt storage pool (deletes nothing)

virsh pool-dumpxml default > pool.xml

Saves a libvirt storage pool config to XML

pkcon refresh force -c -1

Refreshes PackageKit metadata

sed -i 's/^.*KeepCache=.*$/KeepCache=false/' /etc/PackageKit/PackageKit.conf

Stops PackageKit keeping a package cache

dnf clean all --releasever=41

Clears the DNF cache

gsettings set org.gnome.software download-updates false

Stops GNOME Software auto-downloading updates

chmod a+x ~/.local/share/gnome-boxes

Lets other users enter the gnome-boxes directory

gnome-extensions enable system-monitor@gnome-shell-extensions.gcampax.github.com

Enables a GNOME extension (needs full UUID)

dnf config-manager --set-disabled fedora-modular

Disables the fedora-modular repo (legacy)

dnf module reset $MODULE_NAME

Resets a DNF module (legacy)

dnf module list --enabled

Lists enabled DNF modules (legacy)

dnf list installed '*.i*86'

Lists installed 32-bit packages

perl -c somescript_or_module.pl

Checks Perl syntax without running

hwclock --hctosys

Copies hardware clock time to the system

hwclock --systohc

Copies system time to the hardware clock

dnf install @container-tools -y

Installs container tools

rpm-ostree install --idempotent gnome-shell-extension-caffeine

Layers a package; no error if already installed

freshclam

Updates ClamAV virus definitions

dnf --setopt=strict=0 --setopt=install_weak_deps=False install nano

Installs nano without weak dependencies

find ~/logs ~/access-logs ~/tmp/{analog,awstats,webalizer,webalizerftp} -type f \( -name "*.log" -o -name "*.txt" -o -name "*.rs" -o -name "*90a3ac" \) -exec sed -i -E '/djura|dura|80a5ai3dd|tetrakolius|--90a3ac/Id' {} +

Deletes log lines matching keywords

find ~/logs ~/access-logs ~/tmp/{analog,awstats,webalizer,webalizerftp} -type f \( -name "*.log" -o -name "*.txt" -o -name "*.rs" -o -name "*90a3ac" \) -exec grep -H -E 'djura|dura|80a5ai3dd|tetrakolius|--90a3ac' {} \;

Searches logs for keywords

sed -i.bak -e '/^#ControllerMode = dual/s/^#//; /^ControllerMode = le/!s/^ControllerMode = dual$/ControllerMode = le/' -e '/^#AutoEnable=true/s/^#//; /^AutoEnable=false/!s/^AutoEnable=true$/AutoEnable=false/' /etc/bluetooth/main.conf

Sets Bluetooth to LE-only and off at boot (breaks classic devices)

find . -type f | sed -rn 's|.*/[^/]+\.([^/.]+)$|\1|p' | sort | uniq -c | sort -rn

Counts files by extension

echo '<device screen="0" driver="dri2"><application name="Default"><option name="vblank_mode" value="0"/></application></device>' > ~/.drirc

Disables vsync for OpenGL apps via Mesa (overwrites ~/.drirc)

cat /sys/kernel/debug/dri/*/radeon_pm_info

Shows power stats for old radeon-driver GPUs

cat /sys/class/drm/card*/device/power_dpm_force_performance_level

Shows the AMD GPU power level

cat /dev/urandom > /dev/pcspkr

Sends noise to the PC speaker (legacy device)

pacat /dev/urandom

Plays white noise (loud!)

dd if=/dev/urandom of=/dev/null status=progress

Measures random generator speed

echo -e "* hard nproc 2500\n@users hard nproc 3250\nroot hard nproc 3250\n* hard core 0\n* hard maxlogins 2" | sudo tee -a /etc/security/limits.conf

Adds process, core dump and login limits

ulimit -aH

Shows hard resource limits

find . -type f \( -name "*.[Pp][Nn][Gg]" -o -name "*.[Jj][Pp]*[Gg]" -o -name "*.[Gg][Ii][Ff]" -o -name "*.[Ww][Ee][Bb][Pp]" \) -exec exiftool -overwrite_original -all= {} \;

Strips metadata from all images with exiftool

find . -type f -iname '*' -exec exiftool -overwrite_original -all= {} \;

Strips metadata from all files with exiftool

find . -type f \( -name "*.[Pp][Nn][Gg]" -o -name "*.[Jj][Pp]*[Gg]" -o -name "*.[Gg][Ii][Ff]" -o -name "*.[Ww][Ee][Bb][Pp]" \) -exec exiv2 -da rm {} \;

Strips metadata from all images

find . -type f -iname '*' -exec exiv2 -da rm {} \;

Strips metadata from all files exiv2 supports

find . -name "*.[Jj][Pp]*[Gg]" -printf ' jpegoptim > %p\n' -exec jpegoptim -f --strip-none --overwrite --quiet {} \;

Losslessly optimizes all JPEGs with jpegoptim

find . -name "*.[Jj][Pp]*[Gg]" -printf ' jpegtran > %p\n' -exec sh -c 'jpegtran -optimize -copy all "$1" > "$1.tmp" && mv "$1.tmp" "$1"' _ {} \;

Losslessly optimizes all JPEGs with jpegtran

find . -name "*.[Gg][Ii][Ff]" -printf ' gifsicle > %p\n' -exec gifsicle --batch --no-warnings --no-comments --optimize=3 {} \;

Optimizes all GIFs with gifsicle

find . -name "*.[Pp][Nn][Gg]" -printf ' pngcrush > %p\n' -exec pngcrush -ow -rem alla -reduce -brute -q -warn {} \;

Losslessly compresses all PNGs with pngcrush

find . -name "*.[Pp][Nn][Gg]" -printf ' optipng > %p\n' -exec optipng -preserve -clobber -nc -nb -o7 -zm1-9 -quiet {} \;

Losslessly compresses all PNGs with optipng

find . -name "*.[Pp][Nn][Gg]" -printf ' oxipng > %p\n' -exec oxipng -ao max -Z -q {} \;

Losslessly compresses all PNGs with oxipng

flatpak uninstall --unused

Removes unused Flatpak runtimes

qemu-img convert -f vdi -O qcow2 [VBOX-IMAGE.vdi] [KVM-IMAGE.qcow2]

Converts a VirtualBox disk to QEMU/KVM format

VBoxManage modifyhd [VDI] --resize [megabytes]

Resizes a VirtualBox disk

VBoxManage clonehd [old-VDI] [new-VDI] --variant Fixed

Clones a VirtualBox disk (fixed size)

VBoxManage clonehd [old-VDI] [new-VDI] --variant Standard

Clones a VirtualBox disk (dynamic size)

avahi-browse -alr

Lists mDNS services on the network

firewall-cmd --add-service=http --permanent

Opens HTTP in the firewall permanently (applies after --reload)

firewall-cmd --add-service=http

Opens HTTP in the firewall until reboot

echo 'none' > /sys/class/leds/ath9k_htc-phy0/trigger

Turns off a Wi-Fi dongle's LED

logread -t | grep -iE '(warn|crit|err)'

Shows warnings and errors from the system log

cat /sys/kernel/debug/iee*/phy*/airtime_flags

Shows Wi-Fi airtime fairness flags

cat /sys/kernel/debug/iee*/phy*/netdev:wlan*/stations/*/aql

Shows Airtime Queue Limits per Wi-Fi client

cat /sys/kernel/debug/iee*/phy*/aql_enable

Shows whether Airtime Queue Limits are enabled

cat /sys/kernel/debug/iee*/phy*/netdev:wlan*/stations/*/peer_ps_state

Shows power-save state of each Wi-Fi client

cat /sys/kernel/debug/iee*/phy*/netdev:*/aqm

Shows Wi-Fi queue management (aqm) stats

find /sys/kernel/debug/iee*/phy* -name aqm

Finds the Wi-Fi queue management (aqm) files

grep -iE '(BEAMFORME|ANTENNA)' /var/run/hostapd*.conf

Shows beamforming and antenna settings of the Wi-Fi AP

nmap -p0-65535 127.0.0.1 -T5

Scans all ports on localhost

netstat -lntu

Lists listening TCP and UDP ports

ss -lntu

Lists listening TCP and UDP ports

hdsentinel -solid | awk '{print "[\t" $3 "% \t] "$5}'

Shows SSD/HDD health percentage

fstrim -v /

TRIMs the root filesystem on an SSD

grep . /sys/block/sd?/queue/scheduler

Shows the I/O scheduler of each disk

for f in /sys/block/sd?/queue/scheduler; do printf "$f is "; cat $f; done

Shows the I/O scheduler of each disk

grep . /sys/block/sd?/queue/rotational

Shows whether each disk is an HDD (1) or SSD (0)

for f in /sys/block/sd?/queue/rotational; do printf "$f is "; cat $f; done

Shows whether each disk is an HDD (1) or SSD (0)

dmesg | grep -i 'ata link up'

Shows SATA link speeds from the kernel log

seq 3 | xargs -P0 -n1 md5sum /dev/zero

Loads three CPU cores until Ctrl+C

yes > /dev/null &

Loads one CPU core (kill it when done)

dd if=/dev/urandom | bzip2 -9 >> /dev/null

CPU stress test: compresses random data with bzip2

dd if=/dev/zero of=/dev/null

Measures memory copy speed with dd (no disk involved; Ctrl+C to stop)

watch -n 2 cpupower monitor

Shows live CPU frequency and power states every 2 seconds

perf stat -a sleep 2

Shows system-wide CPU performance counters for 2 seconds

@reboot echo -n $USER_DEFINED > /sys/devices/system/cpu/cpufreq/ondemand/up_threshold

Crontab line: sets the ondemand threshold at boot

crontab -e -u pretzel

Edits another user's crontab

echo -n $USER_LIMIT > '/sys/devices/system/cpu/cpufreq/ondemand/up_threshold'

Sets the ondemand governor's load threshold

cpupower -c $CPU_CORES frequency-set -g performance

Sets selected CPU cores to the performance governor

cpupower frequency-set -g performance

Sets the CPU governor to performance

cat /sys/devices/system/cpu/cpufreq/boost

Shows whether CPU boost is enabled

lscpu

Shows a CPU summary: cores, threads, architecture

cat /proc/cpuinfo

Shows detailed CPU info

glxinfo | grep memory

Shows GPU memory info from OpenGL

lspci -vvv | grep modules

Shows kernel modules for PCI devices

lsusb -vs 006:001

Shows details of one USB device

lspci -vs 0a:00.0

Shows details of one PCI device

lspci | grep VGA

Shows the graphics card

find ~/logs/{daily,monthly,weekly} -type f \( -name "*.log" -o -name "*.txt" \) -print0 | xargs -0 sed -i -E '/monday|tuesday/Id'

Deletes lines containing 'monday' or 'tuesday' from log and text files

find . -type f -size +50000k -exec cp -nv {} ./ \;

Copies files larger than ~50 MB from subdirectories into the current directory

find . -type f -name "*.log" -mtime +10 | xargs grep -iEn "(Error 403|Error 404)"

Searches logs older than 10 days for 403/404 errors

find . -maxdepth 1 -type f -name "*apache*" -mtime +10 -exec echo {} \;

Lists files with 'apache' in the name older than 10 days

find . -iname "*.jpeg" -execdir mv -i '{}' cover.jpeg \;

Renames every .jpeg to cover.jpeg in its own directory, asking first

find . -name "*.pdf" -exec cp {} ~/Documents \;

Copies all PDFs from subdirectories into ~/Documents

sed -i 's/^.*NAutoVTs=.*$/NAutoVTs=2/' /usr/lib/systemd/logind.conf

Sets NAutoVTs=2 in logind.conf (updates overwrite /usr/lib; prefer a drop-in in /etc)

sed -i 's/^String=.*$/New String = 22/' file.txt

Replaces lines starting with 'String=' in a file (GNU sed; BSD needs -i '')

dmidecode | awk '/(\t)+Size/{$1=""; print $0 }'

Shows RAM module sizes from dmidecode

awk '/(\t)+Size/{$1=""; print $0 }'

Prints lines with 'Size' after tabs, without the first field

grep -R 'search-string' ~/Some/Path/

Searches for a string in all files under a directory

grep -i -B 3 -A 5 'something something'

Finds a phrase and shows 3 lines before and 5 after each match

grep -iE '(Word1|Word2|Word3)'

Finds lines containing any of the words, case-insensitive

awk -v SEPARATOR="," '{print $1 " " SEPARATOR " " $2 " " SEPARATOR " " $3}'

Adds a comma between the printed fields ($1, $2, and $3) in the output