Misc.

awk '!seen[$0]++' filename

curl --include --verbose --insecure --connect-timeout 1 "{http,https}://10.0.1.[1-254]" -o "10.0.1.#2_#1.html" 2>&1  | tee curl.log

find . -maxdepth 1 -type f -printf '%T@\t%p\n' | sort -t $'\t' -g | head -n -10 | cut -d $'\t' -f 2- | xargs ls -1

ls -1t | sed -e '1,10d' | xargs -d '\n' ls -1

while true; do nc -l -p 80 -q 1 < error.html; done
while true; do { echo -e 'HTTP/1.1 200 OK\r\n'; cat index.html; } | nc -l 8080; done
python2 -m SimpleHTTPServer 8080
python3 -m http.server 8080
twistd -n web –path .
php -S localhost:8080

pandoc -s -f markdown -t html =(curl https://raw.github.com/cyberhouse/doc/master/README.md) | lynx -stdin
pandoc -s -f markdown -t html doc/README.md | lynx -stdin

curl --header 'Host: www.example.com' 'http://localhost/index.php?id=23&L=5'

curl -d @$HOME/.credentials --cookie-jar /tmp/cjar -k https://example.com/?do=login; curl -k --cookie /tmp/cjar --cookie-jar /tmp/cjar https://example.com/foo|lynx -stdin

curl -s -w "%{http_code}\\n" http://www.cyberhouse.at -o /dev/null
# Add -L if you intend to follow location responses

lsof +D /var/log

nmap -sn 172.16.35.0/24 --script ip-forwarding --script-args="target=www.google.com"

ssh server1 tcpdump -i eth3 -U -s0 -w - 'tcp port 80' | wireshark -k -w /tmp/gw.cap -b filesize:50000 -b files:10 -i -
ssh server1 'tshark -f "port !22" -w -' | wireshark -k -i -
tshark -i any -s0 -f 'port !22' -w $(date +%s).pcap

diff .ssh/config <(ssh trillian 'cat .ssh/config')

crontab -l > /tmp/$(whoami)-crontab
echo '* * * * * www-data /var/www/html/typo3/cli_dispatch.phpsh scheduler' >> /tmp/$(whoami)-crontab
crontab /tmp/$(whoami)-crontab
rm /tmp/$(whoami)-crontab

socat TCP4-LISTEN:1234,fork TCP4:192.168.1.1:22' forwards your port   1234 to another machine's port 22. Very useful for quick NAT red

sar -o /tmp/sarlog -A 5 >/dev/null 2>&1
LANG=C; S_TIME_FORMAT="%T; sar -f /tmp/sarlog|les

chattr +i /etc/shadow; lsattr /etc/shadow
chattr -i /etc/shadow; lsattr /etc/shadow

dd if=/dev/zero of=/path/to/swapfile count=2097152 # create 1 G file
mkswap /path/to/swapfile
swapon -p 32767 /path/to/swapfile # use with lowest priority possible

Optionally create an ''/etc/fstab entry: <code> /path/to/swapfile none swap sw,pri=32767 0 0 </code> ===== Reset Root Password, Access to Boot Loader Required ===== Add 1 (after one blank space) or S or Single to the kernel boot parameter to start in single mode. Reset password with passwd check if SELinux is disabled if it does not work (setenforce 0). If single user mode does not work ther is an alternative: Append init=/bin/bash to the boot options, remounting the root partition is necessary (mount -o remount,rw /). ===== Cut Connections from a Specific Address ===== <code> cutter 10.10.0.45 </code> ===== Copy Disk with dd with Progress Bar and Compression ===== <code> parted /dev/sda # Get the disk size first dd if=/dev/sda | pv -s 60022480896 | pigz –fast > /media/myExternalDrive/myBackup.img </code> ===== Write Image with dd with Progress Bar ===== <code> IMAGE=archlinux-2014.04.01-dual.iso && dd bs=1m if=$IMAGE | /opt/local/bin/pv -s $(wc -c $IMAGE) | dd of=/dev/disk1 </code> ===== Get the Filesystem Age ===== <code> tune2fs -l $(df -lh / |(read; awk '{print $1; exit}')) | grep -i created </code> ===== Strace All Processes of a Program, e.g. Apache ===== <code> program=httpd; strace $(ps wuax|grep $program|grep -v grep|awk '{print “-p” $2}'|xargs) -s8192 -r -o /tmp/$program-$(date +%FT%T%z) </code> ===== Log Block Activity to Syslog (or dmesg, Depending on your Ssytem) ===== <code> echo 1 > /proc/sys/vm/block_dump </code> ===== Sorting ps Output by RSS ===== <code> ps auxww | sort -nk6 # or ps auxww –sort +rss </code> ===== Better Readable ps ===== <code> ps auxwwef # or to avoid line wraps ps auxef </code> ===== Get Buffered and Cached Read Speed of Block Device ===== <code> hdparm -Tt /dev/sda </code> ===== Fill Memory Up to Given Percentage ===== <code> stress –vm-bytes $(awk '/MemFree/{printf “%d\n”, $2 * 0.9;}'< /proc/meminfo)k –vm-keep -m 1 </code> ===== Using top in Batch Mode ===== <code> top -b -i -d 10 » /tmp/log/top </code> ===== Simple Port Check with Bash's Built-in /dev/tcp ===== <code> /bin/bash -c “echo >/dev/tcp/144.76.8.201/443 && echo 'open'” </code> ===== Check sudo Permissions of User ===== sudo -U username -l ===== Show OOM score ==== dstat –top-oom ===== Transfer Files without SSH ===== remotely: <code> cat /usr/local/www/munin/memory-month.png | gzip -9c | uuencode /dev/stdin </code> locally: <code> pbpaste | uudecode -o /dev/stdout | gzip -cd > ~/Downloads/memory-month.png </code> ===== List SMB shares on macOS ===== smbutil statshares -a ===== Get Public/External IP Address ===== <code> dig +short myip.opendns.com @resolver1.opendns.com </code> <code> curl ipinfo.io </code> <code> curl ifconfig.me/all </code> <code> curl icanhazip.com </code> <code> curl myip.dnsomatic.com </code> <code> curl whatismyip.akamai.com </code> ==== Add Timestamp to Output ==== <code> vmstat 5 | awk '{system(“/bin/echo -n $(/bin/date”); print “: ” $0}' | tee vmstat-$(date +%F) </code> <code> vmstat 5 | awk '{now=strftime(“%Y-%m-%d %T ”); print now $0}' </code> ==== Monitor Occurrence of Event or State Change and Notify by Terminal Bell ==== <code> while sleep 3; do curl –silent https://wiki.sysop.cafe/misc|grep sleep && tput bel; done </code> <code> while sleep 3; do dig foo.bar.baz +short @8.8.8.8|grep 129 && tput bel; done </code> ==== Terminal bell character ==== <code> printf '\a' echo -en “\007” tput bel </code> ==== Test Hosts on Servers not Available via DNS === <code> curl -H “Host: example.com” 10.0.0.13 </code> <code> wget –header=“Host: example.com” 10.0.0.13 </code> ==== .htpasswd ==== <code> printf “John:$(openssl passwd -crypt V3Ry)\n” » .htpasswd # this example uses crypt encryption </code> <code> printf “Mary:$(openssl passwd -apr1 SEcRe7)\n” » .htpasswd # this example uses apr1 (Apache MD5) encryption </code> <code> printf “Jane:$(openssl passwd -1 V3RySEcRe7)\n” » .htpasswd # this example uses MD5 encryption </code> <code bash> (PASSWORD=“SEcRe7PwD”;SALT=“$(openssl rand -base64 3)”;SHA1=$(printf “$PASSWORD$SALT” | openssl dgst -binary -sha1 | xxd -ps | sed 's#$#'“`echo -n $SALT | xxd -ps`”'#' | xxd -r -ps | base64);printf “Jim:{SSHA}$SHA1\n” » .htpasswd) # this example uses SSHA encryption </code> <code perl> #!/usr/bin/perl use strict; chomp(my $filename=$ARGV[0]); chomp(my $username=$ARGV[1]); chomp(my $password=$ARGV[2]); if (!$filename || !$username || !$password) { print “USAGE: ./crypt.pl filename username password\n\n”; } else { open FILE, “»”, $filename or die $!; print FILE $username . “:” . crypt($password, $username) . “\n”; close FILE or die $!; } </code> ==== Using Comments as Hashtags for Easier History Search ==== <code bash> vim -R /var/db/mysql/percona57.err #mysql-error </code> ==== Getting SIGINFO with Ctrl-T ==== e.g. to get an progress information for a running program like dd, ping, rsync'''.

sed -i -e '3d' ~/.ssh/known_hosts

find /opt/tomcat/temp/ -type f -name '*.xlsx' -mtime +14 -exec rm {} \;

4  5 * * * /usr/local/bin/flock -n /tmp/backup.lock /usr/local/scripts/bbackupfoo.sh