İşe Yarar Linux Komutları

## Bir komutla ilgili yardım
man $keyword
info $command

man -k $keyword
# Örn :
#>kaaygisiz@pc:~$ man -k tcp
#>ip-mptcp (8)         - MPTCP path manager configuration
#>tcp (7)              - TCP protocol
#...
#>tcpdump (8)          - dump traffic on a network

type $command # komut nereden çalışıyor.
# Örn :
#>kaaygisiz@pc:~$ type whoami
#>whoami is /usr/bin/whoami

which $command/$executable
# Örn :
#>kaaygisiz@pc:~$ which go
#>/snap/bin/go

!$		Represents the parameter from the prev command.
!*		Represents all from the previous command
# Örn:
#>kaaygisiz@pc:~/test$ ls a b c
#>a  b  c

#>kaaygisiz@pc:~/test$ wc !$
#>wc c
#>0 0 0 c

#>kaaygisiz@pc:~/test$ wc !*
#>wc a b c
#>1  1  9 a
#>1  1 25 b
#>0  0  0 c
#>2  2 34 total

basename /a/b/c : output c
dirname /a/b/c  : output /a/b
#>kaaygisiz@pc:~/test$ basename /data/workspace/go/sagclick/README.md 
#>README.md

#>kaaygisiz@pc:~/test$ dirname /data/workspace/go/sagclick/README.md 
#>/data/workspace/go/sagclick

# -n line nmber
# -A n line after match
# -B n line before match
# -C both
grep -A5 -B5 -n "11:00:00" server01_access.log00090
grep -C -n "11:00:00" server01_access.log00090
grep -o '[^ ]*$' # sadece dosyaları listele
ls -lrt | grep "Mar 26 17" | grep -o '[^ ]*$'
    
# Büyük boyutlu dosyaları kucuk parcalara böl
split -b 500m server02_osb02_heapdump.tgz heap_dump.tgz.part

# iki line arasındaki kısmı getir. 
awk -v s="$line1" -v e="$line2" 'NR>s&&NR<e' fileName > output.log

#24h (Bunlar bazen cortluyor :D)
awk '/2021-11-03 17:1?/,/2021-11-03 17:2?/' server01.out00855 
awk '/2022-01-17 12:00:0?/,/2022-01-17 13:00:0?/' server01.out | less

#12h
awk '/Jan 14, 2022 12:0?:0? AM/,/Jan 14, 2022 12:12:0? AM/' server01.out 
awk '/2022-02-02 08:32:59/,/2022-02-02 08:46:/' server01.out

sed -n '/Oct 26, 2021 11:20:00 AM/,/Oct 26, 2021 11:35:00 AM/p' server02_osb01.out

# Service call count
# $8 : response time kolonu
grep "/v1/test1" access_server0*_osb0*.log | wc -l 
grep "/v1/test1" access_server0*_osb0*.log | awk '{sum+=$8} END { print "Average = ",sum/NR}'

cat access_server0*_osb0*.log | sort -nr | uniq -c
cat access_server0*_osb0*.log | awk '{ if($8>20) print $0 }' | wc -l
cat access.log | awk '{if($6==500 && $3>"10:00" && $3<"10:30") print $0}'

# Bir komutu belirli aralıklarla tekrar et.
watch -n 10 'echo "test" >> file.f' 

wc -w file.f # get char count
wl -l file.f # get line count

# File Viewing
nl : With line numbers
nl -b a $fileName	# bosluklari da numaralandir

# Replace
sed -i "s/Host=/Host=$_IP/;sUser=/User=$_USERNAME/" file.f # replace properties
sed "-i.`date +%F`" "s|$APP_ROOT\/jdk\/jdkSet|$APP_ROOT\/Java\/jdkSet|g"  file.name

find . -mtime +10 | xargs ls -lrtah
find . -mtime-3 -ls

# find and compress last X day logs 
find . -type f \( -name "*.out*" -o -name "*.log*" \) -mtime -1 | xargs tar -cvzf tarName.tgz

find -type f -newermt "2021-03-26T14:00" \! -newermt "2021-03-26T12:30"
find -type f -name '*.jar' -newermt "2021-12-19" \! -newermt "2021-12-25" | xargs ls -lrtah

# delete
find . -type f -name '*jfr.part' | sed -r 's|/[^/]+$||' -mtime +10 -exec rm {} \;
find . -type f *name '*access*'-newerat 2021-06-10 ! -newerat 2021-06-12

/usr/bin/find $_OUTPUT_PATH -name "std_*.tgz" -mtime +3
find /home/randomcat -mtime +11 -type f -exec gzip {} \;

find . name test*
find ../elasticsearch/ -name *mapping*
    : find under another directory

find . -name *.txt
    : seach for files by extension

find . -type f -name "test*"
    : search only files
find . -type d -name "test*"
    : search for only dir names

find . -iname "Test*"
    : case insensitive

find ./test ./numeric -name file_name.txt -type f
    : search multiple directories

find . -type f ( -name "*.txt" -o -name "*.pdf" -o -name "*.doc" )
    : find multiple files with different extensions	

find . -name "*" -exec grep -il "/Middleware/" {} \; > FindResult.txt
find . -type f -exec grep -li "search_certain_text" {} \;
    : find files containing certain text

find / -size +10M 
    : find files larger than a specified size.

find / -size -10M 
    : find files less than a specified size.

find / -size +100M -size -200M
    : files with sizes between 100-200MB

find . -type f -size 0
find . -type f -empty
    : find empty files

find ./ -type d –empty
    : find empty folders

find /path/ -type -f -name '*.txt' -mtime +8
    : find files older than n days.

atime : access time
mtime : mopdification time
ctime : creation time

find . -amin -10 -type f
    : accessed last 10 min.

find -perm 777
    : find files with permission 777

find /home -user appadmin
    : find files owned by a user

find ver -name "*.php" -type f -exec chmod 755 {} ;
    : find *.php files and chmod to 755

find . -type f -perm 644 -exec chmod 655 {} ;
    : yetkisi 644 olan dosyaları bul ve 655 yap.

#find -iname files_name -exec cp {} ~/to/target/folder ; 
echo target1 target2 target3 | xargs -n 1 cp file_txt;

find ~/tmp/dir1/ ~/tmp/dir2/ $HOME/3/ -maxdepth 0 -exec cp ~/numeric/hci {} ;

# boyutu buyuk dosyaları bi şey yap
du -sh * | sort -rh | head -5 | awk '{print $2}' | xargs

# hidden files included
du -sch .[!.]* * | sort -h

# get OS release
cat /etc/*-release
lsb_release -a

lscpu | egrep 'Model name|Socket|Thread|NUMA|CPU\(s\)' 
less /proc/cpuinfo
grep -c ^processor /proc/cpuinfo

# check mount structure
lsblk -a

#
free -g
free -bg

# VM or Physical Machine
systemd-detect-virt # output: none-> Fiziksel, wmware: Sanal
cat /sys/class/dmi/id/product_name

sar -P ALL -f /var/log/sa/sa14
sar -P ALL -f /var/log/sa/sa10 -s 07:00:00 -e 15:00:00  

#cpu 
# sar 2 10
# sar -p 2 10
# sar  -P ALL 2 10
sar -P ALL -f /var/log/sa/sa14

#memory
sar -r 2 10
sar -r -f /var/log/sa/sa14
sar -R 2 10

# load avg.
sar -q 2 10
sar -q -f /var/log/sa/sa14

#io usage
sar -b 2 10
sar -b -f /var/log/sa/sa14

#disk 
sar -d -p 2 10
sar -d -p -f /var/log/sa/sa14

# Process Kill
ps -ef | grep NodeManager | grep -v grep | awk '{print $2}' | xargs kill -9
ps -ef | grep java -v grep | awk '{print $2}' | xargs kill -9

# HeapDump
$JAVA_HOME/bin/jmap -dump:format=b,file=/opt/tmp/heapdump.bin 37320
$JAVA_HOME/bin/jmap -dump:format=b,file=hprof

kill -3 $pid >> tmp_`date`.log
$JAVA_HOME/bin/jstack $pid >> tmp_`date`.log

source ~/.commonenv
    
# Thread Dump
$JAVA_HOME/bin/jstack $PID > threadDump.log
x=1; while [ $x -le 2 ]; do $JAVA_HOME/bin/jstack $PID >> test_`hostname`_`date '+%Y-%m-%d'`; sleep 10;(( x++ )); done

# GC
$JAVA_HOME/bin/jstat -gcutil $PID 1000 10
    
# Head Dump
$JAVA_HOME/bin/jmap -dump:format=b,file=/path/to/dump.hprof $PID
$JAVA_HOME/bin/jcmd $PID GC.heap_dump /path/to/dump.hprof
    
# JFR - !! duration : 20 dakika !!
$JAVA_HOME/bin/jcmd $PID JFR.start duration=5m filename=/path/to/record_20211210.jfr

#Check Cert
$JAVA_HOME/bin/keytool -list -v -keystore $JAVA_HOME/jre/lib/security/cacerts > /tmp/trusted.txt && less /tmp/trusted.txt
nmap -sV --script ssl-enum-ciphers -p 443 abc.website.com

# Telnet Alternatifi
nc -w 3 -v $ip $port
curl -v telnet://$IP:$PORT

lsof -i:9003

# linux how to see ports in use
lsof -i -P -n | grep LISTEN
netstat -tulpn | grep LISTEN
lsof -i:22 # see a specific port such as 22

nmap -sTU -O IP-address-Here
sudo lsof -i:<port_number>

echo exit | timeout 2s telnet 

# pid'ye göre port bul
lsof -i -P -n | grep $pid

# tcpdump port check	
tcpdump -nnSX port 443
    -nn : Don’t resolve hostnames or port names.
    -S : Get the entire packet.
    -X : Get hex output.
    -t : Give human-readable timestamp output.

# a specific network interface

ifconfig -a 
tcpdump -i $interface_name
tcpdump -i eth0

sudo tcpdump -i any -s 0 -w "`date +'%Y%m%d_%H%M'`_file.pcap"
sudo tcpdump -i any -s 0 -w "`date +'%Y%m%d_%H%M'`_name.pcap"  host dns.com

# with ip
tcpdump host 1.2.3.4
tcpdump src 1.2.3.4
tcpdump dst 1.2.3.4

find HTTP Cookies/headers etc.
tcpdump -vvAls0 | grep 'Set-Cookie|Host:|Cookie:'

wget $URLget --no-check-certificate --http-user=$USER --http-password=$PASSWORD -r -nH --no-parent --level=1 --no-directories --reject="*.sha1" --progress=bar:force "${URL}" 2>&1

curl  -H "Content-Type: text/xml; charset=utf-8" -H "SOAPAction:" -u $uuserna:$pass -d @request_file $URL