Linux Learning Notes Linux directory Architecture _unix Linux

Linux Directory Architecture


/root directory


/bin commonly used commands binary file's catalogue


/boot store files that must be read when the system is started, including the core (kernel)


/boot/grub/menu.lst Grub Settings


/boot/vmlinuz kernel


RAM Disk required for/BOOT/INITRD core decompression


/dev System Peripheral Equipment


/ETC System Related setup file


/etc/dir_colors Set Color


/etc/hostname set the user's node name


/etc/networking only yes indicates network presence


/etc/host.conf file describes how the user's system queries the section roll name


/etc/hosts set the user's own IP and name of the corresponding table


/etc/hosts.allow settings allow use of inetd machines


/etc/hosts.deny settings do not allow use of inetd machines


/ETC/HOSTS.EQUIV set remote machine without password


/etc/inetd.conf set up the System network daemon process inetd configuration


/etc/gateways Set Router


/etc/protocols set System-supported protocols


/etc/named.boot Configure the computer as the name server configuration file


/etc/sysconfig/network-scripts/ifcfg-eth0 Set IP


/etc/resolv.conf Set DNS


/etc/x11 X Window configuration file, xorg.conf or xf86config these two x Server settings


/etc/fstab record the file system on which to mount


/etc/inittab sets the system to what runlevel the init process will set up when the system starts


/etc/issue record the information displayed before the user logs in


/etc/group set the user's group name and related information


/ETC/PASSWD account Information


/etc/shadow Password Information


/etc/sudoers can sudo command configuration file


/etc/securetty to set which terminals can log root


/etc/login.defs The default configuration for all users when they log on


/etc/exports to set the NFS system


/etc/init.d/all of the service's preset script is placed here, such as to activate or close


/etc/xinetd.d/This is what is called the "Super Daemon Management" set of services.


/etc/modprobe.conf Kernel module Additional parameter setting


/etc/syslog.conf Log Settings file


/home User Home Directory


function libraries that the/lib system will use


Related modules of/lib/modules kernel


/VAR/LIB/RPM RPM Kit Installation Office


When the/lost+found system is wrong, some missing fragments are placed in this catalogue.


Mount point of/mnt Peripherals


/media and/mnt are similar


/OPT Host additional installed software


/proc Virtual directory, is the memory of the map


/proc/version kernel version


/proc/sys/kernel System kernel function


/root system Administrator's home directory


Instructions to be executed by the/sbin system administrator


/srv Some of the services that need to be taken into account,


/TMP general user or where the program being executed is temporarily placed


/usr the largest directory, save applications and files


/usr/x11r6:x-window Directory


/usr/src:linux Source Code


/usr/include: System Header File


/usr/openwin Store Sun's Openwin


/usr/man Online User Manual


/usr/bin the user can perform the binary file


/usr/local/bin the user can perform the binary file


function libraries that the/USR/LIB system will use


function libraries that the/USR/LOCAL/LIB system will use


Instructions to be executed by the/usr/sbin system administrator


Instructions to be executed by the/usr/local/sbin system administrator


/var log File


/var/log/secure record access to data files, such as POP3, SSH, Telnet, FTP, etc. are recorded in this file.


/var/log/wtmp Record login information, last


/var/log/messages Almost system error messages


/var/log/boot.log or when it's time to start a service, the activation or shutdown is displayed.


User records for/var/log/maillog access or coming (SendMail and POP3)


/var/log/cron Records crontab The content of this routine service


/VAR/LOG/HTTPD,/var/log/news,/var/log/mysqld.log,/var/log/samba,/var/log/procmail.log:


A couple of different Web services.











Some of the most common basic commands:


Uname-a View Kernel version


Ls-al Display properties for all files


PWD Show current path


CD-Back to previous directory CD ~ Return to home directory


Date s set time, dates


CAL Displays calendar Cal 2006


BC Computing Apparatus


Man & Info Help manual


Locale Display the current font locale-a all available fonts/etc/sysconfig/i18n settings file


lang=en Use English fonts


Sync writes data to the hard disk synchronously


Shutdonw-h now & half & Poweroff shutdown


Reboot reboot


StartX & Init 5 into the graphics interface


/work & Work Find document content up and down


Chgrp Change file group CHGRP testing Install.log


Chown Change the person chown root:root Install.log


chmod change attribute chmod 777 Install.log read=4 write=2


CP replication CP filename


RM Delete file rm-rf filename Force Delete file


RmDir Delete Folder


MV Mobile MV 123.txt 222.txt Rename


mkdir Create a folder


Touch Create file Update current time


Cat starts with the first line showing cat |more pagination


NL add line number to front of content


More & less Side flip


Head-n filename shows nth row content


Tail-n filename shows the contents of the following n lines


OD Display non-pure documents


DF-H Display partition space


Du displays the size of the directory or file


Fdisk partition settings fdisk-l/dev/hda show hard disk partition status


MKFS establish various file systems Mkfs-t EXT3/DEV/RAM15


FSCK check and repair Linux files


ln hard link ln-s software link


Whereis Lookup Command


Locate find


Find finding/-name "***.***"


Which viewing tool


WHOAMI Display Current User


Gcc-v View GCC version


chattr +i filename Prohibit deletion of chattr-i filename cancellation ban


Lsattr Show hidden file properties


UpdateDB Update Repository


MKE2FS format mkfs-t ext3


DD IF=/ETC/PASSWD Of=/tmp/passwd.bak Backup


Mount lists all partitions of the system


MOUNT-T Iso9660/dev/cdrom/mnt/cdrom Mount CD


MOUNT-T Vfat/dev/fd0/mnt/floppy mounted floppy disk


MOUNT-T Vfat-o IOCHARSET=UTF8,UMASK=000/DEV/HDA2/MNT/HDA2 Mount FAT32 partition


MOUNT-T Ntfs-o NLS=UTF8,UMASK=000/DEV/HDA3/MNT/HDA3 Mount NTFS partitions


Linux-ntfs project:http://linux-ntfs.sourceforge.net/


Umount/mnt/hda3 Unloading load


Ifconfig display or set up network devices


Service Network restart Reboot network card


Ifdown eth0 off the NIC


Ifup eth0 Open Network card


Clear Screen


History history!55 Execute 55th instruction


Stty Set Terminal stty-a


FDISK/MBR Delete Grub


At a single working schedule


Crontab routine command [e] edit, [l] show, [R] Delete task


& Background Running program TAR-ZXVF 123.tar.gz &---------> Background run


Jobs Watch Background Paused program Jobs-l


FG Transfer Background program to the foreground FG N------>n is a number that can be specified for that program


BG lets work run in the background


Kill End Process Kill-9 PID [9] Force end, [15] ends normally, [l] lists available kill signals


PS aux view background program


Top View Daemon top-d 2 Update once every two seconds top-d 2-p10604 watch a PID


Top-b-N 2 >/tmp/top.txt-----> Make top information 2 times and then output the results to/tmp/top.txt


Pstree the program in a tree diagram [A] connects in ASCII, lists the PID,


List account number


Killall to delete a service killall-9 httpd


Free display memory status free-m--------> show in M


Uptime shows current system boot time


Netstat Display network status NETSTAT-TULNP------> Find out the current system has been listening to the link and its PID


DMESG display boot Information demsg | More


Nice set Priority Nice-n-5 VI &-----> with root to a nice plant-5, used to perform VI


Renice adjustment already exists priority


RunLevel shows the current runlevel


Depmod analysis of dependencies of loading modules


LSMOD displays the modules that have been loaded into the system


Modinfo display information for kernel modules


Insmod Loading Module


Modprobe Automatic Process Loading module


Rmmod Delete Module


Chkconfig Check, set up the system of various services Chkconfig--list-----> List Service Status


NTSYSV set up various services for the system


Cpio Backup Files











Compression command:


*. Z Compress program compressed file;


*.BZ2 bzip2 Program compressed file;


*.GZ gzip program compressed file;


The *.tar of the TAR program is not compressed;


*.tar.gz the TAR program, where it has been compressed by gzip


Compress filename Compressed file plus [d] decompression uncompress


gzip filename compression plus [d] Extract zcat 123.gz View compressed file contents


bzip2-z filename compression plus [d] Extract bzcat filename.bz2 View compressed file contents


TAR-CVF/HOME/123.TAR/ETC package, no compression


TAR-XVF 123.tar untie Package


Tar-zxvf/home/123.tar.gz with gzip decompression


TAR-JXVF/HOME/123.TAR.BZ2 to bzip2 Decompression


tar-ztvf/tmp/etc.tar.gz View tar Content


Cpio-covb > [File|device] Part


Cpio-icduv < [file|device] Restore





VI General Usage


General mode edit mode instruction mode


H Left A,i,r,o,a,i,r,o:w Save


J Enter edit mode: w! Force Save


K on DD Delete cursor current line: q! Do not save leave


L Right NDD delete n line: wq! Leave after saving


0 move to the beginning of YY copy current line: e! Restore Original file


$ move To line end Nyy copy n rows: w filename Save As


H screen Top p,p paste: Set nu setting line number


M-Screen Central U undo: Set Nonu cancel line number


L screen at the bottom [ctrl]+r Redo last action ZZ save leave


The last line of the G file [ctrl]+z pause exit: Set Nohlsearch permanently closes highlighting


/work Search: SP opens two documents at the same time


? work search up [ctrl]+w two document change


GG move to file first line: Nohlsearch temporarily turn off highlighting





Understanding Shell


Alias displays all current command aliases alias lm= "Ls-al" command alias unalias lm cancel command alias


Type similar to which


Exprot setting or displaying environment variables


Exprot path= "$PATH":/sbin add/sbin to Path


echo $PATH Display path Path


Bash into subroutine


Name=yang Set Variable


unset name Cancel Variable


echo $name Display the contents of a variable


Myname= "$name its i" & Myname= ' $name its me ' single quotes $name lose variable content


ciw=/etc/sysconfig/network-scripts/set Path


ENV Lists all environment variables


echo $RANDOM show randomly generated numbers


Set setting shell


Ps1= ' [\u@\h \w \a #\#]\$ ' prompt character set


[Root@linux ~]# read [-pt] variable-----------reading variables for keyboard input


Parameters:


-P: The back side can receive the prompt character!


-T: The back can wait "seconds!" 』


Declare declaring shell variables


ULIMIT-A Display all restricted data


Ls/tmp/yang && echo "Exist" | | echo "not exist"


It means that when Ls/tmp/yang is done, if it is true, it performs the echo "exist", and if there is a problem, the echo "not exist" is executed.


echo $PATH | Cut-d ': '-F 5 to: Read the 5th paragraph as a separator


Export | Cut-c 10-20 reads the 10th to 20th byte content


Last | grep ' root ' searches for a line with root, plus [-v] Reverse Search


cat/etc/passwd | Sort order Display


cat/etc/passwd | WC shows "line, Word, number of bytes"


Formal representations


[Root@test root]# grep [-acinv] ' search string ' filename


The parameters say:


-A: binary files are searched in text file


-C: Calculate the number of ' search string '


-I: Ignores the difference in size, so the size is written in the same


-N: Enter the travel number


-V: Reverse selection, which shows the line without the ' search string ' content!


Grep-n ' The ' 123.txt searches the character-----------search for specific strings


Grep-n ' t[ea]st ' 123.txt search test or taste two characters---------use [] to search for collection characters


Grep-n ' [^g]oo ' 123.txt search for oo-----------not preceded by G [^]


Grep-n ' [0-9] ' 123.txt search has 0-9 digits


Grep-n ' ^the ' 123.txt search at the beginning of the line-----------


Grep-n ' ^[^a-za-z] ' 123.txt search does not begin with an English letter


Grep-n ' [a-z]$ ' 123.txt search ends with a-Z line----------end of line


Grep-n ' G.. d ' 123.txt search for the beginning G End D character----------any character.


Grep-n ' ooo* ' 123.txt search for at least two OO characters---------a duplicate character *


Sed text flow editor uses script commands to work with text files


AWD mode scanning and processing languages


NL 123.txt | Sed ' 2,5d ' deletes the contents of the second to the fifth line


Diff Comparison file differences


CMP compares two files for differences


Patch Patch files


PR format of the file to be printed








Account Management


/ETC/PASSWD System Account Information


/etc/shadow account password information through MD5 32-bit encryption


In front of the password bar, add "*" "!" Prohibit the use of an account


/etc/group System Group Information


/etc/gshadow


NEWGRP Change Landing Group


Useradd & AddUser Create a new user---------> Useradd-m test automatically create a user's login directory


Useradd-m-G pgroup Test---------> Specify owning Level


/etc/default/useradd Related Settings


/etc/login.defs Uid/gid the setting


passwd Change Password-----------> passwd test


Usermod Modify user Account


Userdel Delete account----------->userdel-r test


The shell [-l] used by CHSH to replace the login system displays the available shell; [-S] Modify your shell


CHFN change the information displayed by the finger command


Finger finds and displays user information


ID Displays the user ID-----------> ID Test


Groupadd Add a group


Groupmod and Usermod are similar


Groupdel Delete Group


Su test changes user Su-into root and uses the environment variables of root


sudo executes instructions in a different capacity.


Visudo Edit/etc/sudoers Join one line "Test all= (All)"


%wheel all = (all) users of all wheel groups in the system can use sudo


%wheel all = (all) Nopasswd:all Wheel group All users are not password nopasswd


User_alias ADMPW = Vbird, Dmtsai, Vbird1, vbird3 join ADMPW Group


ADMPW all = nopasswd:!/usr/bin/passwd,/usr/bin/passwd [a-za-z]*, \


!/USR/BIN/PASSWD root can change the user password, but cannot change the root password (join before the instruction!)


PAM (pluggable authentication Modules, embedded modular Group)


Who & W Look who's online


Last recent landing of the host information


Lastlog recently logged in to read/var/log/lastlog


Talk Chat with other users


Write send message write test [ctrl]+d send


MESG Set Terminal Write permission MESG n prohibit receiving MESG y


Wall send information to all users wall this is Q test


Mail Write Mail


/etc/default/useradd Home Directory default settings


Quota shows the space used by the disk with the limit Quota-guvs-----> show out the current quota limit of root values


Quota-vu Query


Quotacheck Check disk usage space and Limitations quotacheck-avug-----> to scan all partition in/etc/mtab containing quota support


[-m] forced scan


Quota must be independent of the partition, to have Quota.user and quota.group two files, add a sentence in/etc/fstab:


/dev/hda3/home ext3 Defaults,usrquota,grpquota 1 2


chmod quota* Setup completed, restart effective


Edquota edit users or groups of quota users, [g] groups,


Copy, [t] set grace period


Edquota-a Yang edquota-p yang-u-----> Replication


Quotaon Open disk space limit QUOTAON-AUVG--------> Activate all filesystem with quota


Quotaoff Turn off disk space limits quotaoff-a--------> shut down quota restrictions


Repquota-av the limit state of all quota filesystem in the search system


Quota from the beginning of the preparation of filesystem support to the whole set of the main step is probably:


1, set partition filesystem support quota parameters:


Since the quota must make the partition above filesystem support, generally speaking, the best support is EXT2/EXT3,


Other filesystem, I didn't try! The easiest way to activate filesystem support quota is to edit/etc/fstab,


Make ready to open the quota disk can support quota;


2, the establishment of quota record files:


As I mentioned earlier, the entire quota disk limit record file is Aquota.user/aquota.group,


To build these two files, you have to use the Quotacheck to scan.


3. Edit quota Limited Value data:


Again, use the Edquota to edit each user or group's available space.


4. Re-scan and activate quota:


After setting a good quota, the advice can be quotacheck again, and then quotaon to activate it!





Introduction to the boot process


1, loaded into the BIOS of the hard information, and obtain the first device generation;


2. Read the boot Loader (that is, Lilo, Grub, Spfdisk, and so on) for the first device's MBR;


3, load into the Kernel operating system core information, Kernel began to decompress, and try to drive all hardware devices;


4, Kernel execute the INIT program and obtain run-level information;


5, Init executed/etc/rc.d/rc.sysinit file case;


6, activate the core of the outer Die Group (/etc/modprobe.conf);


7, the Init performs the run-level each batch file (Scripts);


8, Init executed/etc/rc.d/rc.local file case;


9. Execute the/bin/login program and wait for the user to login;


10, login to start with the Shell to control the main machine.


In/etc/rc.d/rc3.d, the start starts with S, the closure begins with K, then the number represents the order of execution.


GRUB VGA settings


Color degree resolution 640x480 800x600 1024x768 1280x1024 bit


256 769 771 773 775 8 Bit


32768 784 787 790 793 bit


65536 785 788 791 794 bit


16.8M 786 789 792 795 bit





./configure check System information./configure--help | More help information


Make clean erase files left before


Make compilation


Make install Installation


RPM-Q-----> Query whether to install RPM-QL------> Query All directories of the suite


RPM-QI-----> Enquiry Kit RPM-QC[D]-----> Profile and Specification file


RPM-IVH----> Installation rpm-v--------> see if the kit has been altered


RPM-E------> Remove RPM-UVH-------> Upgrade Installation


--nodeps-----> Forcibly install--test-----> Test Installation