Linux Tips 和shell Tips
Linux Tips 和shell Tips
Intro
Shell command collect
loop a to z
for w in {a..z}
awk array
netstat -n | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}'
time wait bucket table overflow in CentOS 6 见
netstat -nt | cut -c 40- | cut -d: -f1 | sort | uniq -c | sort -n
generate password
date +%s | sha256sum | base64 | head -c 32 ; echo
format number
echo 18888888888888888888 | rev | sed 's/.../&,/g' | rev
18,888,888,888,888,888,888
get double 双色球
echo -e '\e[0;31m' $(shuf -i 1-33 | head -n6 | sort -n) '\e[0;34m' $(shuf -i 1-16 | head -n1) '\e[0m'
DDos bad boy
for i in `netstat -an | grep -i ':80 '|grep 'EST' | awk '{print $5}' | cut -d : -f 1 | sort | uniq -c | awk '{if($1 > 50) {print $2}}'`
echo $i
echo $i >> /tmp/banip
/sbin/iptables -A INPUT -p tcp -j DROP -s $i
done
bash ssh command
alias ssh='strace -o /tmp/sshpwd-date '+%d%h%m%s'.log -e read,write,connect -s2048 ssh'
pass function Usage who-to e.g:doom-gmail
pass () { echo $1-$2 | md5sum | sha1sum | awk -F '[1a2b]' '{for (i=1;i<=NF;i++) if ( length($i)>= 6) print$i}' | sed -n '1p' | sed -n 's/[3c]/\%/gp'}
dd for progress
while killall -USR1 dd; do sleep 5; done
Gnu/linux user security
chage -d 0 -m 0 -M 90 -W 15 root
awk half an hour ago
awk '{split($1,d,"-");split($2,t,":");epoch = mktime(d[1]" "d[2]" "d[3]" "t[1]" "t[2]" "t[3])}(systime()-epoch)<1800{print} ' log
ssh 通过中间机跳两次(How do I SSH to machine A via B in one command)
ssh -t user@B ssh user@A
ip2dec ip地址转换成十进制
`ip2dec () { local a b c d ip=$@ ; IFS=. read -r a b c d <<< "$ip"; printf '%d\n' "$((a * 256 ** 3 + b * 256 ** 2 + c * 256 + d))"; }
`
PS1 vs PROMPTCOMMAND(PS1 PROMPTCOMMAND 的区别)
If set, the value is interpreted as a command to execute before the printing of each primary prompt ($PS1).
PROMPT_COMMAND就是PS1之前的打印的信息。
e.g.
[ops@c6_v20 ~]$ export PROMPT_COMMAND="echo -n echo "
echo[ops@c6_v20 ~]$
另一个例子:
[doom@doomarch ~]$export PS1="Im PS1 "
Im PS1 export PROMPT_COMMAND='echo -n "Im PROMPT_COMMAND " '
Im PROMPT_COMMAND Im PS1
测试UDP连通(nc telnet>TCP)
nc -vuz 223.5.5.5 53
导出sqlite3到sql文件
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.mode insert <target_table_name>
.out file.sql
select * from MyTable;
sqlite3 vs mysql 加入rowid
sqlite3
select (select COUNT(0)
from test1 t1
where t1.b <= t2.b
) as 'Row Number', b from test1 t2 ORDER BY b; mysql
SELECT @a:=@a+1 serial_number,
marks
FROM student_marks,
(SELECT @a:= 0) AS a;乱序一个文件
while read i;do echo "$i $RANDOM";done < file.dict|sort -k2n|cut -d" " -f1"
Bash replace spaces in file name
for f in *\ *; do mv "$f" "${f// /_}"; done
Every http parsed to json or dict
awk -F '; ' '{for (i=1;i<=NF;i++) {split($i, a, "=");printf"\047%s\047: \047%s\047,", a[1], a[2]}}'
download bigfile
aria2c -c -k1M -{x,j,s}16 --checksum=md5=dccff28314d9ae4ed262cfc6f35e5153 http://mirrors.zju.edu.cn/ubuntu-releases/14.04/ubuntu-14.04-desktop-amd64.iso
backup txt files
$ rsync -avzm --include '*/' --include '*.txt' --exclude '*' source/ remote:target/
transfer file at 100kB/s
rsync -hP --bwlimit 100 remote:file .
convert json to csv
jq -r '[.field1,.field2,.field3]|@csv' input.json > output.csv
convert socks5 to http
delegate -P8080 SERVER=http SOCKS=1.2.3.4:1080 ADMIN=admin@datageek.info
convert socks5 to http with auth
delegated -f -P8080 SERVER=http FORWARD=socks://user:pass@1.2.3.4:1080 ADMIN=admin@datageek.info
zero-padding file names
rename 's/^\d+/sprintf("%02d", $&)/e' [0-9]*
concat video parts
printf "file '%s'\n" part*.mp4 | ffmpeg -f concat -i - -c copy all.mp4
tcpdump 抓http包，header显示 保存到 -w sth.recv
sudo tcpdump -vvvnns 1550 -i eth0 dst port 80 -w sth.recv
vim每行增加行数
:%s/^/\=line('.').','/
调整lvm大小
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umount /home
resize2fs /dev/i-vg/home
lvreduce -L -20G -f /dev/i-vg/home
lvresize -L +20G /dev/i-vg/root
resize2fs /dev/i-vg/root
引用
Reference: url