1, the system will log the user's current information into the capital to /tmp/who.out saved as a file.
[root@centos7 ~]#who | tr [:lower:] [:upper:] > /tmp/who.out [root@centos7 ~]#cat /tmp/who.out ROOT :0 2019-06-03 15:45 (:0) ROOT PTS/0 2019-06-03 15:59 (192.168.30.1)
2, calculates the sum of 1 + 2 + 3 + ... + 99 + 100.
[root@centos7 ~]#echo {1..100} | tr ' ' + | bc 5050
[root@centos7 ~]#seq -s + 100 | bc 5050
3, common user and file management commands which, and demonstrate command and usage.
User management commands:
Change password
passwd
[root@centos7 ~]#echo '12345678' | passwd --stdin kkk Changing password for user kkk. passwd: all authentication tokens updated successfully.
Create a user
useradd
[root@centos7 ~]#useradd user001
Modify user information
usermod
[root@centos7 ~]#usermod -g kkk -aG root -u 6666 user001
delete users
userdel
[root@centos7 ~]#userdel -r user1
Creating user groups
groupadd
[root@centos7 ~]#groupadd group001
Modify user group information
groupmod
[root@centos7 ~]#groupmod -g 6666 -n group002 group001
Deleting User Groups
groupdel
[root@centos7 ~]#groupdel group002
Displaying a user, group information
getent
[root@centos7 ~]#getent passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown stop: x: 7 : 0 : wait: / sbin: / sbin / halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin abrt:x:173:173::/etc/abrt:/sbin/nologin libstoragemgmt:x:998:997:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin colord:x:997:996:User for colord:/var/lib/colord:/sbin/nologin saslauth:x:996:76:Saslauthd user:/run/saslauthd:/sbin/nologin rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin chrony:x:995:993::/var/lib/chrony:/sbin/nologin qemu:x:107:107:qemu user:/:/sbin/nologin tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin geoclue:x:994:991:User for geoclue:/var/lib/geoclue:/sbin/nologin rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin radvd:x:75:75:radvd user:/:/sbin/nologin setroubleshoot:x:993:990::/var/lib/setroubleshoot:/sbin/nologin pulse:x:171:171:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin gdm:x:42:42::/var/lib/gdm:/sbin/nologin gnome-initial-setup:x:992:987::/run/gnome-initial-setup/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin ntp:x:38:38::/etc/ntp:/sbin/nologin tcpdump:x:72:72::/:/sbin/nologin Kkk: X: 1000 : 1000 : Kkk, IT, 10086 , 10000 : / Home / Kkk: / Bin / Bash tomcat:x:1001:1004::/home/tomcat:/bin/bash mysql:x:1002:1005::/home/mysql:/bin/bash user2:x:1004:1008::/home/user2:/bin/bash user3:x:1005:1009::/home/user3:/bin/bash
[root@centos7 ~]#getent group root:x:0: am: x: 1 : daemon:x:2: sys:x:3: adm:x:4: tty:x:5: disk:x:6: lp:x:7: mem:x:8: kmem:x:9: wheel:x:10: cdrom:x:11: mail:x:12:postfix man:x:15: dialout:x:18: floppy:x:19: games:x:20: tape:x:30: video:x:39: ftp:x:50: lock:x:54: audio: x: 63 : nobody:x:99: users:x:100: utmp:x:22: utempter:x:35: input:x:999: systemd-journal:x:190: systemd-network:x:192: dbus:x:81: polkitd:x:998: abrt:x:173: libstoragemgmt:x:997: rpc:x:32: colord:x:996: cgred:x:995: dip:x:40: ssh_keys:x:994: saslauth:x:76: rtkit:x:172: chrony:x:993: kvm:x:36:qemu qemu:x:107: tss: x: 59 : libvirt:x:992: usbmuxd:x:113: geoclue:x:991: rpcuser:x:29: nfsnobody:x:65534: radvd:x:75: setroubleshoot:x:990: pulse-access:x:989: pulse-rt:x:988: press: x: 171 : gdm:x:42: gnome-initial-setup:x:987: sshd:x:74: opens: x: 70 ; slocate:x:21: postdrop:x:90: postfix:x:89: ntp:x:38: stapusr:x:156: stapsys:x:157: stapdev:x:158: tcpdump:x:72: Kkk: X: 1000 : Kkk webs:x:1001: apps:x:1002:tomcat dbs:x:1003:mysql tomcat:x:1004: mysql:x:1005: user001:x:1006: user2:x:1008: user3:x:1009: user1group:x:1010:
[root@centos7 ~]#getent shadow root:$6$fhGPsICHwt401JgQ$5X5y3oDmIBzerlIbNeRFjnXs01bgbVTMLa4oRDQjP8z5fJKDHAGSL7IBjjqB5c9BifVSHXhwlnoVD./0fLhok1::0:99999:7::: bin:*:17110:0:99999:7::: daemon:*:17110:0:99999:7::: adm:*:17110:0:99999:7::: lp:*:17110:0:99999:7::: sync:*:17110:0:99999:7::: shutdown:*:17110:0:99999:7::: halt:*:17110:0:99999:7::: mail:*:17110:0:99999:7::: operator:*:17110:0:99999:7::: games:*:17110:0:99999:7::: ftp:*:17110:0:99999:7::: nobody:*:17110:0:99999:7::: systemd-network:!!:18033:::::: dbus:!!:18033:::::: polkitd: !!: 18033 :::::: Abrt: !!: 18033 :::::: libstoragemgmt: !!: 18033 :::::: rpc:!!:18033:0:99999:7::: colord:!!:18033:::::: saslauth: !!: 18033 :::::: rtkit: !!: 18033 :::::: chrony:!!:18033:::::: qemu:!!:18033:::::: TSS: !!: 18033 :::::: usbmuxd:!!:18033:::::: geoclue:!!:18033:::::: rpcuser:!!:18033:::::: nfsnobody:!!:18033:::::: radvd:!!:18033:::::: setroubleshoot:!!:18033:::::: pulse:!!:18033:::::: gdm:!!:18033:::::: gnome-initial-setup:!!:18033:::::: sshd:!!:18033:::::: avahi:!!:18033:::::: postfix:!!:18033:::::: ntp:!!:18033:::::: tcpdump:!!:18033:::::: kkk: $ 6 $ $ BMwLhCs1 yuv9kNhqstfVbNx10wZg9sV72pds1I2utcPDRDxgzzGjzfV / eJjVBeduqF8n.3J4flhrXZ.9QR / GLn7NBZ0 / o0: 18051 : 0 : 99999 : 7 ::: tomcat:!!:18051:0:99999:7::: mysql:!!:18051:0:99999:7::: user2:!!:18051:0:99999:7::: user3:!!:18051:0:99999:7:::
[root@centos7 ~]#getent gshadow root::: bin::: daemon::: sys::: adm::: tty::: disk::: lp::: mem::: kmem::: wheel::: cdrom::: mail:::postfix man::: dialout::: floppy::: games::: tape::: video::: ftp::: lock::: audio::: nobody::: users::: utmp:!:: utempter: ! :: input:!:: systemd-journal:!:: systemd-network:!:: dbus:!:: polkitd: ! :: Abrt: ! :: libstoragemgmt: ! :: rpc:!:: colord:!:: cgred:!:: dip:!:: ssh_keys:!:: saslauth: ! :: rtkit: ! :: chrony:!:: kvm:!::qemu qemu:!:: TSS: ! :: libvirt:!:: usbmuxd:!:: geoclue:!:: rpcuser:!:: nfsnobody:!:: radvd:!:: setroubleshoot:!:: pulse-access:!:: pulse-rt:!:: pulse:!:: gdm:!:: gnome-initial-setup:!:: sshd:!:: avahi:!:: slocate:!:: postdrop:!:: postfix:!:: ntp:!:: Stpusr: ! :: stapsys:!:: Stpdev: ! :: tcpdump:!:: kkk: $ 6 $ NpCZ5 / 9u878 / $ yzrgz8nItDezMkPawxAIKV.40SQPLPUuV21yr0w.MKU32AhMiFc6uVZMqVNj31dTP31IseNtBufAC5AMedQG7 / :: kkk webs:!:: apps:!::tomcat dbs:!::mysql tomcat:!:: mysql:!:: user001:!:: user2:!:: user3:!:: user1group:!::
View user id information
id
[root@centos7 ~]#id kkk uid = 1000 (kkk) gid = 1000 (kkk) groups = 1000 (kkk)
Switch User
its
[root@centos7 ~]#su - kkk Last login: Tue Jun 4 22:47:51 CST 2019 on pts/0
File management commands
Edit text file contents
nano
[root@centos7 ~]#nano f1
View catalog file
ls
[root@centos7 ~]#ls -a . anaconda-ks.cfg .cache dead.letter Documents .esd_auth initial-setup-ks.cfg Music Public Videos .. .bash_history .config Desktop Downloads .ICEauthority .local Pictures Templates
View the file properties list
ll、ls -l
[root@centos7 ~]#ll total 12 -rw-------. 1 root root 1894 May 17 08:35 anaconda-ks.cfg -rw-------. 1 root root 14 Jun 1 15:33 dead.letter drwxr-xr-x. 2 root root 6 May 17 08:44 Desktop drwxr-xr-x. 2 root root 6 May 17 08:44 Documents drwxr-xr-x. 2 root root 6 May 17 08:44 Downloads -rw-r--r--. 1 root root 1925 May 17 08:43 initial-setup-ks.cfg drwxr-xr-x. 2 root root 6 May 17 08:44 Music drwxr-xr-x. 2 root root 6 May 17 08:44 Pictures drwxr-xr-x. 2 root root 6 May 17 08:44 Public drwxr-xr-x. 2 root root 6 May 17 08:44 Templates drwxr-xr-x. 2 root root 6 May 17 08:44 Videos
Modify the file owner, all groups
chown
[centos7 root @ ~] # Chown kkk: kkk / date / f1
View files three times
stat
[root@centos7 ~]#stat /data/f1 File: ‘/data/f1’ Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 803h/2051d Inode: 67 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 1000/ kkk) Gid: ( 1000/ kkk) Context: unconfined_u:object_r:etc_runtime_t:s0 Access: 2019-06-05 01:52:08.860744447 +0800 Modify: 2019-06-05 01:52:08.860744447 +0800 Change: 2019-06-05 01:52:57.333748189 +0800 Birth: -
copy
cp
[root@centos7 ~]#cp -a /data/f1 .
Move or rename files
mv
[root@centos7 ~]#mv /data/f1 /data/f2
delete
rm
[root@centos7 ~]#rm -f /data/f1 [root@centos7 ~]#rm -rf /data/dir1/
Create an empty directory
mkdir
[root@centos7 ~]#mkdir /data/dir1
Create an empty file
>>、touch、>
[root@centos7 ~]#>> /data/f2 [root@centos7 ~]#touch /data/f1 [root@centos7 ~]#> /data/f3
View text files
cat
[root@centos7 ~]#cat /data/f1 test
Modify files for all groups
chgrp
[root@centos7 ~]#chgrp kkk /data/f1
Modify file permissions
chmod
[root@centos7 ~]#chmod 777 /data/f1
ACL settings file
setfacl
[root@centos7 ~]#setfacl -m u:user2:r /data/f1
View Files ACL
[root@centos7 ~]#getfacl /data/f1 getfacl: Removing leading '/' from absolute path names # file: data/f1 # owner: root # group: kkk user::rwx user:user2:r-- group::rwx mask::rwx other::rwx
To view or modify the file permissions reservations
umask
[root@centos7 ~]#umask 0022 [root@centos7 ~]#umask 0024 [root@centos7 ~]#umask -p umask 0024 [root@centos7 ~]#umask -S u=rwx,g=rx,o=wx
Determine the file type
file
[root@centos7 ~]#file /usr/bin/cat /usr/bin/cat: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=fac04659ab9a437b5384c09f4731023373821a39, stripped [root@centos7 ~]#file /data/f1 /data/f1: ASCII text
Create link
ln
[root@centos7 ~]#ln -s /data/f1 /root/f1_link
View source path corresponding soft link
readlink
[root@centos7 ~]#readlink f1_link /data/f1
4, create a user gentoo, additional group bin and root, the default shell is / bin / csh, annotation information "Gentoo Distribution".
[root@centos7 ~]#useradd -G bin,root -s /bin/csh -c "Gentoo Distribution" gentoo [root@centos7 ~]#getent passwd gentoo gentoo:x:6673:6675:Gentoo Distribution:/home/gentoo:/bin/csh [root@centos7 ~]#id gentoo uid=6673(gentoo) gid=6675(gentoo) groups=6675(gentoo),0(root),1(bin)
5, a new file in / testdir / dir created in the group automatically belong webs, members of the group apps such as: tomcat to have read and write access to these new documents, dbs group members such as: mysql can only read access to the new file, other users (not part webs, apps, dbs) can not access this folder.
[root@centos7 ~]#groupadd webs [root@centos7 ~]#groupadd apps [root@centos7 ~]#groupadd dbs [root@centos7 ~]#useradd tomcat -G apps [root@centos7 ~]#useradd mysql -G dbs [root@centos7 ~]#mkdir -p /testdir/dir [root@centos7 ~]#chgrp webs /testdir/dir/ [root@centos7 ~]#chmod g+s /testdir/dir/ [root@centos7 ~]#ll -d /testdir/dir/ drwxr-sr-x. 2 root webs 6 Jun 5 01:28 /testdir/dir/ [root@centos7 ~]#setfacl -Rm g:apps:6 /testdir/dir/ [root@centos7 ~]#setfacl -Rm g:dbs:4 /testdir/dir/ [root@centos7 ~]#setfacl -Rm o::0 /testdir/dir/ [root@centos7 ~]#getfacl /testdir/dir/ getfacl: Removing leading '/' from absolute path names # file: testdir/dir/ # owner: root # group: webs # flags: -s- user::rwx group::r-x group:apps:rw- group:dbs:r-- mask::rwx other::---
6, to find the ip address of ifconfig. The results show only requires IPv4 address of this machine.
[root@centos6 ~]#ifconfig | grep 'inet addr' | tr -s ' ' : | cut -d : -f 4 192.168.1.120 192.168.30.101 127.0.0.1
7, to identify the user name of the user maximum UID, UID and shell type.
[root@centos6 ~]#cut -d : -f 1,3,7 /etc/passwd | sort -t : -k 2 -nr | head -n 1 nfsnobody:65534:/sbin/nologin
8, the file to copy /etc/rc.d/init.d/functions the / tmp directory, replace / tmp / functions file / etc / sysconfig / init is / var / log.
:%s@/etc/sysconfig/init@/var/log@g