Alawn/Interview-Notebook

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CyC2018 7e4d5152f7 auto commit

2018-02-22 14:47:22 +08:00

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???ò??????????
- ????
- ???
- ??????
- ?????
- PATH
- ???е??
- sudo
- GNU
- ????????
- ???????а汾
????
- ??????????
- ??????
  - 1. MBR
  - 2. GPT
- ??????????
  - 1. BIOS
  - 2. UEFI
- ????
??????????????
???????
- ??????
- ????????????????
  - 1. ls
  - 2. cp
  - 3. rm
  - 4. mv
- ??????????
  - 1. cat
  - 2. tac
  - 3. more
  - 4. less
  - 5. head
  - 6. tail
  - 7. od
  - 8. touch
- ????????????
???????????
???????
- ???
  - 1. gzip
  - 2. bzip2
  - 3. xz
- ???
BASH
??????????????????????
- grep
- printf
- awk
vim ??????
?ο?????

???ò??????????

????

1. --help

????????÷??????????

2. man

man ?? manual ????д???????????????????????

????? man date ????? DATE(1) ????????е??????????????????????????????????????

????	????
1	????? shell ?????п?????????????????????
5	???????
8	?????????????????????

3. info

info ?? man ????????? info ???????????????棬?????????????????

???

1. ???????д????? sync

?????????????????д????λ??????е?????????????????????????????????????????? sync ?????????

2. shutdown

# /sbin/shutdown [-krhc] [???] [??????]
-k ?? ???????????????????????????????????
-r ?? ???????????????????????
-h ?? ??????????????????????
-c ?? ??????????е? shutdown ???????

3. ??????????

reboot??halt??poweroff??

??????

ps ??䶮

????? theadx ??????????

ps aux | grep threadx

?????

netstat ??䶮

???????? 80 ???????

netstat -anp | grep 80

PATH

????????????? PATH ????????????????·????·??????? : ?????

/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/dmtsai/.local/bin:/home/dmtsai/bin

???е??

0??????? 1????????????????????root???? 2?????????????????? 3?????????????????????????????????????????? 4????????δ??? 5???????????? X-windows ??????????????棩 6????????????????????

sudo

??? sudo ????????????? root ????е????䶮????????? /etc/sudoers ?в?????????䶮

GNU

GNU ????????????ū?????????????????????????????????????? GNU???????????????? GPL ????????????? GPL ???? GNU ??ù??????Э?飬???????????????

???κ???????д??????????
???????????
?????????????????????????ɡ?

????????

RPM ?? DPKG ???????????????????????RPM ???? Redhat Package Manager???????? Red Hat ????????????? GNU ???????????????????? Linux ?? (RHEL) ?????????????? RPM ???о?????????? Debian ?????? (UBUNTU) ?? DEB ???????????? DPKG?????? Debian Package??????????? RPM ?????

YUM ???? RPM ?????????????????????????????????????????????????? RPM ???????????????????????????????????????????????????????????????????????????????????????????????????YUM ???????????????????????????????????

???????а汾

Linux ???а??????????? Linux ????????????????

???? DPKG

??????а?

Ubuntu

???????а?

Debian

???? RPM

??????а?

Red Hat

???????а?

Fedora
CentOS

????

??????????

Linux ????????????????????????

????????????????

SCSI/SATA/USB ?????/dev/sd[a-p]
IDE ?????/dev/hd[a-d]

??????????????????????????????????й??????????????????λ??????

??????

?????????????????????????????????? MBR ???????????????????????? GPT ??????

1. MBR

MBR ?У??????????????????????У?????????????Master boot record, MBR??????????partition table???????? MBR ? 446 bytes??partition table ? 64 bytes??

????????? 64 bytes????????洢 4 ?????????? 4 ???????????????Primary?????????????Extended?????????????????????????????????????????????????????????????????????????????????????????????Щ????????????????

Linux ???????????????????????????????????????????+???????? /dev/sda1????????????????? 5 ?????

2. GPT

?????????в??????????С?????? 512bytes ?????????? 4k??GPT ?????????д?????????????????????????????Logical Block Address, LBA????

GPT ?? 1 ?????????? MBR?????????? 33 ????????????????????????? 33 ????????????????????б????

GPT ????????????????????????????????? 128 ????????

??????????

1. BIOS

BIOS ????????????????е??????????????????????????????????????????????????? MBR???? MBR ??????е?????????????????????????????????????????????

MBR ?е????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? MBR ?е???????????????????????????????????????????????????????????????????????????????

???????????????????? Windows ???? Linux???????? Windows ?????? MBR???? Linux ???????????????????? MBR ???????????????????????????????????????????????????

2. UEFI

UEFI ????? BIOS ???????????棬?????????

????

?????????????????????????????????????????????????????????

??????????????

?????????

?????????????????????????????????????????????в???????????

??? ls ????????????????????????????????? drwxr-xr-x. 3 root root 17 May 6 00:14 .config????????????????????

drwxr-xr-x?????????????????? 1 λ??????????Σ??? 9 λ?????????Ρ?
3??????????
root???????????
root????????飻
17???????С??
May 6 00:14???????????????
.config?????????

???????????????京???У?

d??????
-???????
l???????????

9 λ????????????У?? 3 ?????飬?? 3 ?飬??????????????????????????????????????????????????е? 3 λ???? r??w??x ??????????????д??????С?

?????????????????

1. ?????????????

# chgrp [-R] groupname dirname/filename
-R????????

2. ???????????

?????????????????????????????????????顣

# chown [-R] ?????:????? dirname/filename

3. ??????

?????????????????????????????????? 3 ??λ???????????????λ???????????λ????? 4??2??1????????????????????? r??4??w??2??x??1??

# chmod [-R] xyz dirname/filename

???????? .bashrc ???????????? -rwxr-xr--??

# chmod 754 .bashrc

???????÷??????趨????

# chmod [ugoa]  [+-=] [rwx] dirname/filename
- u???????
- g?????????
- o????????
- a????????
- +????????
- -????????
- =???趨???

??????? .bashrc ???????????????д????

# chmod a+w .bashrc

???????

?????????洢???????????????У?????洢????????????????С????????????? w ??????????????????????

???洢????б???????????????????????б?????????????? r ???????????????б?w ????????????????б????????????????????????????????????????x ??????????????????????x ????? r ?? w ??????????????????????????????????????????????б??????????б??????????

?????????

??????????????????п???????????? 666 ??????? -rw-rw-rw- ?? ?????????????????????????????????п???????????? 777 ??????? drwxrwxrwx??

??????? umask ???????????????????????????????????????????? 002 ??????????????????????? 2 ???????????д???????????????????????? -rw-rw-r-- ??

??????

??????? Linux ???а汾????????????????Filesystem Hierarchy Standard (FHS) ?涨?? Linux ??????????????????????????

/ (root, ????)
/usr (unix software resource)????????????????????????????
/var (variable)???????????????й????е??????????

???????????????

???????

??????

modification time (mtime)????????????????????
status time (ctime)??????????????????????????????
access time (atime)????????????????

????????????????

1. ls

?г???????????????????????????????а??????????

# ls [-aAdfFhilnrRSt] file|dir
-a ???г?????????
-d ?????г???????
-l ?????????????г???????????????????????????

2. cp

?????????

?????????????????????????????????????С?

cp [-adfilprsu] source destination
-a ?????? -dr --preserve=all ??????????? dr ??ο????????
-d ?????????????????????????????????????????????
-i ?????????????????????????????????
-p ?????????????????????
-r ????????????
-u ??destination ?? source ?????? destination???? destination ????????????????
--preserve=all ?????? -p ??????????????????? SELinux ??????, links, xattr ?????????

3. rm

?????????

# rm [-fir] ???????
-r ????????

4. mv

?????????

# mv [-fiu] source destination
# mv [options] source1 source2 source3 .... directory
-f ?? force ????????????????????????????????????????

??????????

1. cat

???????????

# cat [-AbEnTv] filename
-n ????????к?? ??????????????к???? -b ??????

2. tac

?? cat ?????????????????п???????

3. more

????????????????????????????????

4. less

?? more ?????

5. head

??????????????С?

# head [-n number] filename
-n ??????????????????????е????

6. tail

?? head ????????????????????С?

7. od

??????????????????????????????????????

8. touch

??????????????????????

# touch [-acdmt] filename
-a ?? ???? atime
-c ?? ???? ctime?????????????????????????
-m ?? ???? mtime
-d ?? ????????????????????????????????????????? --date="????????"
-t ????????????????????????????????????[YYYYMMDDhhmm]

????????????

1. which

?????????

# which [-a] command
-a ????????????г???????????е????

2. whereis

whereis ??????????????????????????????????????

# whereis [-bmsu] dirname/filename

3. locate

locate ?????ù????????????????????????

locate ??? /var/lib/mlocate/ ???????????????????????洢??????У?????????????Σ?????????? locate ????????????????????? updatedb ???????????????

# locate [-ir] keyword
-r???????????

4. find

find ?????????????????????????????

# find filename [option]

4.1 ??????й?????

-mtime  n ???г??? n ??????????????????????
-mtime +n ???г??? n ????(???? n ????)????????????
-mtime -n ???г??? n ?????(?? n ????)????????????
-newer file ?? ?г??? file ????????

+4??4 ?? -4 ?????????Χ?????

4.2 ???????????????????й?????

-uid n
-gid n
-user name
-group name
-nouser ???????????????? /etc/passwd ?????
-nogroup????????????鲻?????? /etc/group ?????

4.3 ??????????????й?????

-name filename
-size [+-]SIZE??????? SIZE ?????(+)??С(-)?????????? SIZE ?????У?c: ???? byte??k: ???? 1024bytes??????????? 50KB??????????????? -size +50k
-type TYPE
-perm mode  ???????????? mode ?????
-perm -mode ???????????? mode ?????
-perm /mode ??????????????? mode ?????

???????????

??????????

????????и????????????????????????????????????????????????????????????????е???????????????????????????????????????????????????????????????????

???????????????????

superblock????????????????????????? inode ?? block ?????????????????????????????????????????????
inode?????????????? inode???????????????????????????????????? block ????
block????????????????????????????????? block??

????????????????????????? inode ??????????????????????? block?????????? block ?????????????

????????????????????????? block ????????

Ext2 ???????????????????????????????????? block ????????????????????????????? block ??飬???????

inode

Ext2 ????????? block ??С?? 1k??2k ?? 4k ?????????? block ??С??????????????С??????? inode ??С????? 128 bytes??

inode ?м???????????????? block????????? block ???С?????????????????????? block??????? inode ??С???????????????????? block?????????????????????????????????? block ???????С????????? block ?????????????? block??

inode ????????????????

???????????(read/write/excute)??
?????????????????(owner/group)??
?????????????
????????????????????(ctime)??
?????ε??????(atime)??
??????????(mtime)??
???????????????(flag)???? SetUID...??
????????????????? (pointer)??

???? inode ?? block

???????????????????? inode ????????? block??block ???????????????????????? inode ????????????????????????? inode ???????????????????????????У????????????????????????????????Щ?????????? w ????й??

????????????????

# ln [-sf] source_filename dist_filename
-s ??????? hard link???? -s ? symbolic link
-f ????????5?????????????????????

1. ???????

hard link ?????????????????????????????????????????????? inode ?????????????????????????????????????????? 0??

????????????????? Filesystem??????????????????

# ln /etc/crontab .
# ll -i /etc/crontab crontab
34474855 -rw-r--r--. 2 root root 451 Jun 10 2014 crontab
34474855 -rw-r--r--. 2 root root 451 Jun 10 2014 /etc/crontab

2. ????????

symbolic link ???????? Windows ????????????????????????????????????????????????????????????????????????????????????????

symbolic link ????????????????

# ll -i /etc/crontab /root/crontab2
34474855 -rw-r--r--. 2 root root 451 Jun 10 2014 /etc/crontab
53745909 lrwxrwxrwx. 1 root root 12 Jun 23 22:31 /root/crontab2 -> /etc/crontab

???????

???

Linux ?????к????????????????????????????

?????	???????
*.Z	compress
*.zip	zip
*.gz	gzip
*.bz2	bzip2
*.xz	xz
*.tar	tar ???????????????о??????
*.tar.gz	tar ????????????????? gzip ?????
*.tar.bz2	tar ????????????????? bzip2 ?????
*.tar.xz	tar ????????????????? xz ?????

1. gzip

gzip ?? Linux ?????????????????? compress??zip ?? gzip ????????????

???? gzip ?????????????????????

?? 9 ???????????????????á?

??????? zcat??zmore??zless ??????????????????

$ gzip [-cdtv#] filename
-c ???????????????????????
-d ???????
-t ??????????????????
-v ??????????????
-# ?? # ???????????????????????????????????????????6

2. bzip2

???? gzip ???????????

??????bzcat??bzmore??bzless??bzgrep??

$ bzip2 [-cdkzv#] filename
-k ??????????

3. xz

???? bzip2 ???????????

?????????gzip??bzip2??xz ??????????????????????????????????????????????

??????xzcat??xzmore??xzless??xzgrep??

$ xz [-dtlkc#] filename

???

????????????????????????????????????????????????????????tar ???????????????????????? gip??bzip2??xz ?????????????????

$ tar [-z|-j|-J] [cv] [-f ?????tar???] filename...  ==??????
$ tar [-z|-j|-J] [tv] [-f ???е?tar???]              ==??
$ tar [-z|-j|-J] [xv] [-f ???е?tar???] [-C ??]    ==?????
-z ?????zip??
-j ?????bzip2??
-J ?????xz??
-c ?????????????
-t ??????????????????Щ?????
-x ??????????????????
-v ???????/???????????У???????????????????
-f : filename?????????????
-C ?? ?? ??????????????

????????????

?????? ?? tar -jcv -f filename.tar.bz2 ??????????????????? ?? ?? ?? tar -jtv -f filename.tar.bz2 ????? ??tar -jxv -f filename.tar.bz2 -C ??????????

BASH

??????? shell ?????????????Bash ???? shell ??????

Bash????

1. ???????

?????ù??????䶮???ε??????е??????????????????У? ~/.bash_history ????м?????????ε??????й??????䶮

2. ????????????

??????tab

3. ????????

???? lm ?? ls -al ???????

4. shell scripts

5. ????

???? ls -l /usr/bin/X* ?г? /usr/bin ?????????? X ??????????

????????

?????????????????? = ??????????????????????? $ ????????? ${} ????????????????? echo ???䶮

$ var=abc
$ echo $var
$ echo ${var}

????????????п????????????????????????????????????????????????????????var="lang is $LANG"????var???? lang is zh_TW.UTF-8??????????????????????????????????????? var='lang is $LANG'???? var ???? lang is $LANG??

??????? `???` ???? $(???) ????????????н????????????????? version=$(uname -r)???? version ???? 3.10.0-229.el7.x86_64??

??????? export ???????????????????????????????????????????????????ν???????????? Bash ?????????? Bash??

Bash ?????????????????????????????????????????и?????????????????????????????????????????????????? declare ????

$ declare [-aixr] variable
-a ?? ?????????????
-i ?? ?????????????
-x ?? ?????????????
-r ?? ?????readonly????

??? [ ] ??????????в?????

$ array[1]=a
$ array[2]=b
$ echo ${array[1]}

??????????

?????????·?????????????? /bin/ls ???? ./ls ??
?????????????????У?
?? Bash ????????????У?
?? $PATH ?????????????·??????????????????????С?

???????????

???????????????????????????????????????????

??????? (stdin) ??????? 0 ????? < ?? << ??
?????? (stdout) ??????? 1 ????? > ?? >> ??
??????????(stderr)??????? 2 ????? 2> ?? 2>> ??

???У?????????????????????????????????????????????????????

??????????????????????????????????? /dev/null ???????????????

??????????????????????????????????????????????????????????????????????? 2>&1 ???????????????????????????

$ find /home -name .bashrc > list 2>&1

???????

??????????????????????????????????????????????????????????????????????????????????????????ù???????????????? | ??????????????䶮

$ ls -al /etc | less

1. ??????cut

????????????е???С?

cut ??????????з??????????????

$ cut
-d ???????
-f ?????? -d ???????? -f n ????? n ??????
-c ??????????λ???????

????1??last ????????????????????????????????

$ last
root pts/1 192.168.201.101 Sat Feb 7 12:35 still logged in
root pts/1 192.168.201.101 Fri Feb 6 12:13 - 18:46 (06:33)
root pts/1 192.168.201.254 Thu Feb 5 22:37 - 23:53 (01:16)

$ last | cut -d ' ' -f 1

????2???? export ????????????? 12 ??????????????????

$ export
declare -x HISTCONTROL="ignoredups"
declare -x HISTSIZE="1000"
declare -x HOME="/home/dmtsai"
declare -x HOSTNAME="study.centos.vbird"
.....(???????).....

$ export | cut -c 12

2. ????????sort??uniq

sort ????????

$ sort [-fbMnrtuk] [file or stdin]
-f ???????Сд
-b ??????????????
-M ?????·???????????????? JAN, DEC
-n ?????????
-r ??????????
-u ?????? unique ?????????????????
-t ?????????????tab
-k ??????????????

??????/etc/passwd ???????? : ?????????????????????

$ cat /etc/passwd | sort -t ':' -k 3
root:x:0:0:root:/root:/bin/bash
dmtsai:x:1000:1000:dmtsai:/home/dmtsai:/bin/bash
alex:x:1001:1002::/home/alex:/bin/bash
arod:x:1002:1003::/home/arod:/bin/bash

uniq ?????????????????????

$ uniq [-ic]
-i ???????Сд
-c ?????м???

??????????????????????

$ last | cut -d ' ' -f 1 | sort | uniq -c
1
6 (unknown
47 dmtsai
4 reboot
7 root
1 wtmp

3. ???????????tee

?????????????????????????У??? tee ??????????????????????????????????????????????? tee ?????????????????????????????

$ tee [-a] file

4. ?????????tr??col??expand??join??paste

tr ???????????е???????????????????滻??

$ tr [-ds] SET1 ...
-d ?? ??????? SET1 ????????

???????? last ????????????Сд??????д??

$ last | tr '[a-z]' '[A-Z]'

col ?? tab ?????????????

$ col [-xb]
-x ?? ?? tab ?????????????

expand ?? tab ??????????????????? 8 ????

$ expand [-t] file
-t ??tab ??????????

join ????????????????к???????

$ join [-ti12] file1 file2
-t ????????????????
-i ???????Сд?????
-1 ????????????????????
-2 ????????????????????

paste ????????????????

$ paste [-d] file1 file2
-d ????????????? tab

5. ???????split

split ????????????????????

$ split [-bl] file PREFIX
-b ?????С?????з?????????λ?????? b, k, m ??
-l ?????????????з?????
- PREFIX ??????????????????

??????????????????????

grep

???????????????????????????

$ grep [-acinv] [--color=auto] ???????? filename
-a ?? ?? binary ????? text ??????????????
-c ?? ???????????
-i ?? ?????Сд
-n ?? ????к?
-v ?? ????????????????? ???????? ??????????
--color=auto ??????????????????

??????????? the ??????????????????????????? --color=auto ???????????????? Linux ?????????? the ???????

$ grep -n 'the' regular_express.txt
8:I can't finish the test.
12:the symbol '*' is represented as start.
15:You are the best is mean you are the no. 1.
16:The world Happy is the same with "glad".
18:google is the best tools for search keyword

??? { ?? } ??????? shell ???????????????????????????????????????塣

$ grep -n 'go\{2,5\}g' regular_express.txt

?????????????ο? ???????.

printf

?????????????

????????????????? printf ????????????? $( ) ?????

$ printf '%10s %5i %5i %5i %8.2f \n' $(cat printf.txt)
    DmTsai    80    60    92    77.33
     VBird    75    55    80    70.00
       Ken    60    90    70    73.33

awk

$ awk '???????? 1{???? 1} ???????? 2{???? 2} ...' filename

awk ??δ?????У????????С??λ????Σ??????ε???????????$n??n ???κ???? 1 ?????$0 ???????С?

???? 1???????????????????? ip

$ last -n 5
dmtsai pts/0 192.168.1.100 Tue Jul 14 17:32 still logged in
dmtsai pts/0 192.168.1.100 Thu Jul 9 23:36 - 02:58 (03:22)
dmtsai pts/0 192.168.1.100 Thu Jul 9 17:23 - 23:36 (06:12)
dmtsai pts/0 192.168.1.100 Thu Jul 9 08:02 - 08:17 (00:14)
dmtsai tty1 Fri May 29 11:55 - 12:11 (00:15)

$ last -n 5 | awk '{print $1 "\t" $3}

awk ??????

????????	????????
NF	??????е????????
NR	???????????????????
FS	???????????????????

???? 2??????????????к????????????ж??????

$ last -n 5 | awk '{print $1 "\t lines: " NR "\t columns: " NF}'
dmtsai lines: 1 columns: 10
dmtsai lines: 2 columns: 10
dmtsai lines: 3 columns: 10
dmtsai lines: 4 columns: 10
dmtsai lines: 5 columns: 9

?????????????????????е?????? ==??

???? 3??/etc/passwd ????????????? UID???? UID С?? 10 ????????д???

cat /etc/passwd | awk 'BEGIN {FS=":"} $3 < 10 {print $1 "\t " $3}'
root 0
bin 1
daemon 2

vim ??????

????????????????????????????????洢?????

????	????
:w	д?????
:w!	???????????????д???????????????д???????????????????й?
:q	??
:q!	???????????
:wq	д????????
:wq!	???д????????

?ο?????

???. ?? ?? ?? Linux ? ?? ?? ?? ?? ? ?? ?? ??[J]. 2009.
Linux ??????????????

24 KiB Raw Blame History Unescape Escape

???ò??????????

????

???

??????

?????

PATH

???е??

sudo

GNU

????????

???????а汾

????

??????????

??????

1. MBR

2. GPT

??????????

1. BIOS

2. UEFI

????

??????????????

?????????

?????????????????

1. ?????????????

2. ???????????

3. ??????

???????

?????????

??????

???????

??????

????????????????

1. ls

2. cp

3. rm

4. mv

??????????

1. cat

2. tac

3. more

4. less

5. head

6. tail

7. od

8. touch

????????????

1. which

2. whereis

3. locate

4. find

4.1 ??????й?????

4.2 ???????????????????й?????

4.3 ??????????????й?????

???????????

??????????

inode

???? inode ?? block

????????????????

1. ???????

2. ????????

???????

???

1. gzip

2. bzip2

3. xz

???

BASH

Bash????

????????

??????????

???????????

???????

1. ??????cut

2. ????????sort??uniq

3. ???????????tee

4. ?????????tr??col??expand??join??paste

5. ???????split

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grep

24 KiB

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