Advanced Linux Commands

Configuration file

• . BASHRC/.ZSHRC
  Save personal personalization settings, such as command aliases, paths, and so on. The. BASHRC is typically called explicitly in the. bash_profile file. Log in to Linux to start bash first read the ~/.bash_profile file, so that ~/.BASHRC will be executed, your personalized settings will be effective

System administrators manage files for users and user groups

• /etc/passwd
• /etc/shadow
• /etc/group
• /etc/gshadow

File Directory Operation cat

• Three major functions
  1. Display the entire file at once: Cat filename
  2. Create a file from the keyboard: cat > FileName can only create new files and cannot edit existing files.
  3. Merge several files into one file: Cat file1 file2 > file
• -b,–number-nonblank number of non-null output lines

• -n,–number the number of all rows of the output, starting from 1 for the number of rows for all outputs

  -n log2012.log> log2013.log

• TAC Log.txt Reverse Listing

Head/tail

• Head-n 5 Log2014.log Display the first n rows of a file
• Head-c Log2014.log Display the first n bytes of a file
• Head-c -32 log2014.log file except for the last n bytes
• Head-n-6 log2014.log output file except the last n rows of the entire content

More/less

• More +3 Log2012.log Displays the contents of the file from line 3rd
• More +/day3 Log2012.log finds the first line from a file that appears with the "Day3" string, and displays the output from the first two lines at that point
• More-5 Log2012.log Set the number of rows per screen
• Ls-l | More-5

Mv

• -f:force mandatory Meaning, if the target file already exists, will not be asked and directly covered;
• -T: –target-directory=directory move all source arguments into directory, which is the target directory for the specified MV, which is suitable for moving multiple source files to a directory, when the target directory is in front, The source file is behind.

nl

The NL command is used in a Linux system to calculate the line number of a file. NL can automatically add a line number to the output file content! Its default result and cat-n a bit different, NL can do more than the line number display design, including the number of digits and whether auto-completion 0, etc.

Rm

• Custom Recycle Bin
  Open the. bashrc or. zshrc file and add the following command at the rear:

  myrm(){ D=/tmp/$(date +%Y%m%d%H%M%S$D;     "[email protected]"$D"moved to $D ok"; }alias myrm=‘myrm‘

  Source. ZSHRC is in effect, you can use the Myrm command.

Touch

• -R Sets the date and time of the specified document or directory to the same date and time as the reference document or directory

  -rlog.log log2012.log

• -T uses the specified datetime instead of the current time format [[cc]yy]mmddhhmm[. SS]

  -t201211142234.50log.log

File Lookup Find

• Find. -size +1000c-print find files larger than 1K in the current directory

Locate

Ocate allows users to quickly search the file system for specific files. The method is to set up a database that includes all the file names and paths within the system, and then simply query the database when looking for it, rather than actually going deep into the file system. In the general distribution, the establishment of the database is placed in the crontab automatic execution
PS: Sometimes the computer may not have locate command, this time need to install mlocate, and then use UpdateDB to update it.

Whereis

The Whereis command locates the location of the executable file, the source code file, the Help file in the file system
*-B Locate executable file, binary file
*-M location Help file
*-S location source code file

which

The purpose of the which command is to search for the location of a system command in the path specified by the path variable, and return the first search result

File package upload and download

• Differentiate between packaging and compression
  Packaging refers to a large number of files or directories into a total file, compression is a large file through some compression algorithm into a small file. Many of the compression programs in Linux can only be compressed for one file, so when you want to compress a lot of files, you have to first make a package (tar command) of this large number of files, and then compress the program (gzip bzip2 command).

Use SecureCRT to upload and download file tar

Used to compress and decompress files. The tar itself does not have compression capabilities. It is implemented by invoking the compression function

• -X extracting files from compressed files
• -Z Support gzip unzip files
• -C Create a new compressed file
• -V Show Operation procedure
• -f Specifies the compressed file

• -D Record File differences

  FileNameFileName.tar DirName

  .gz解压1FileName.gz解压2FileNameFileName

  .tar.gz.tgz解压：tar zxvf FileName.tar.gz压缩：tar zcvf FileName.tar.gz DirName

  .bz2解压1FileName.bz2解压2FileNameFileName

  .tar.bz2解压：tar jxvf FileName.tar.bz2压缩：tar jcvf FileName.tar.bz2 DirName

  .bz解压1：bzip2 -d FileName.bz解压2：bunzip2 FileName.bz压缩：未知

  .tar.bz解压：tar jxvf FileName.tar.bz压缩：未知

  FileNameFileName

  .tar.Z解压：tar Zxvf FileName.tar.Z压缩：tar Zcvf FileName.tar.Z DirName

  .zip解压：unzip FileName.zip压缩：zip FileName.zip DirName

  .rarx FileName.rar压缩：rar a FileName.rar

File Permission Settings chgrp

Use the CHGRP directive to change the group to which files and directories belong

• Group and group identifiers can be viewed in the/etc/group file.
• -V Run-time display verbose processing information

• –dereference acts on the point of a symbolic link, not the symbolic link itself

  -v bin log2012.log--reference=log2012.log log2013.log-R-R100 test6

Chown command

Change the file owner and group by Chown. You can use the user name and user identification number settings when you change the owner or group of the file. Ordinary users cannot change their files to other owners. Its operation permissions are generally administrators.

• -R handles all files in the specified directory and its subdirectories

• -V displays detailed processing information

  改变拥有者和群组chown mail:mail log2012.log 改变文件拥有者和群组chown root: log2012.log改变文件群组chown :mail log2012.logchown -R -v root:mail test6

Disk storage related DF

• Necessary parameters
  
  • -A All File system list
  • -h easy to read mode display
  • -H equals "-H", but the formula, 1k=1000, rather than 1k=1024
  • -I display inode information
  • -K block is 1024 bytes
  • -L show local file system only
  • -M block is 1048576 bytes
  • –no-sync Ignore sync command
  • -P output format POSIX
  • –sync perform the sync command before obtaining the disk information
  • -T File system type
• Select parameters
  
  • –block-size=< Chunk Size > specified chunk size
  • -t< file system type > show only disk information for selected file systems
  • -x< file System type > does not display disk information for the selected file system
  • Help Display Help information
  • –version displaying version information

Du

暂时使用的较少，不详述

Performance monitoring and optimization top

Displays information about the processes currently being executed by the system, including process IDs, memory usage, CPU utilization, etc.

• Common parameters
  
  • -B Batch Processing
  • -C Displays the complete ruling command
  • -I ignores the failure process
  • -S Secret mode
  • -S cumulative mode
  • -i< time > Set time interval
  • -u< User name > Specify user name
  • -p< Process number > Specify process
  • -n< number of times > cycle display
• Example
  　
  
  • The first line: The current system time, up xxx running for how long, the current 1 users logged in, load average the three numbers are 1 minutes, 5 minutes, 15 minutes of the load situation. If this number is divided by the number of logical CPUs, the results above 5 indicate that the system is overloaded.
  • Second line: Total number of processes, zombie is zombie
  • PID line: Process ID; Process owner; Process priority (PR); Nice value, negative indicates high priority, positive values represent low priority; VIRT, total amount of virtual memory used by the process, in kilobytes. Virt=swap+res;res, the size of the physical memory, in kilobytes, that the process uses and has not been swapped out. Res=code+data;

Free

The free command displays system usage and idle memory conditions, including physical memory, interactive area memory (swap), and kernel buffer memory. Shared memory will be ignored

• Command parameters
  
  • -B Displays memory usage in bytes.
  • -K displays memory usage in kilobytes.
  • -m displays memory usage in megabytes.
  • -G displays memory usage in gigabytes.
  • -O does not display buffer throttling columns.
  • -s< interval seconds > Continuous observation of memory usage.
  • -T displays the memory sum column.
  • -V Displays version information.
• Memory rating File: Cat/proc/meminfo

• Instance

  freefree -gfree -mfree1//每秒执行一次

Vmstat/iostat Command/lsof command

还没接触到，先不做解释http://www.cnblogs.com/peida/archive/2012/12/25/2833108.html

Network Command Ifconfig

The NIC information configured with the Ifconfig command does not exist after the machine restarts after the network card restarts. In order to keep the above configuration information in the computer forever, it is necessary to modify the network card configuration file.

• Command parameters
  
  • Up starts the specified network device/NIC.
  • Down to turn off the specified network device/NIC.
  • ARP settings specify whether the NIC supports ARP protocol

• Instance

  Starting and closing the NIC Ifconfig eth0Upifconfig ETH0Down for NIC configuration IPv6 address ifconfig ETH0Add -Ffe:3240: -:1005::2/ -Modify with IfconfigMACAddress Ifconfig ETH0HW etherxx: AA: BB: CC:D D: EEConfigurationIPAddress Ifconfig ETH0 192.168.120.56Netmask255.255.255.0Broadcast192.168.120.255Enable and CloseARPProtocol Ifconfig ETH0Arpifconfig ETH0-arp Setting the Maximum Transmission unit ifconfig ETH0Mtu the

rcp (remote file copy)

The RCP command copies files or directories at the remote end, such as specifying more than two files or directories at the same time, and the final destination is a directory that already exists, it will copy all previously specified files or directories to that directory.

• command Arguments
  
  • -R recursively copies all the contents of the source directory to the destination directory. To use this option, the destination must be a directory.
  • -P attempts to preserve the modified time and mode of the source file, ignoring umask.
  • -K requests that RCP obtain a Kerberos license for the remote host within the specified zone, rather than obtaining a Kerberos license for the remote host in the remote host zone determined by Krb_relmofhost⑶.
  • -X turns on DES encryption for all transmitted data. This affects response time and CPU utilization, but it can improve security. If the path specified in the file name is not the full pathname, then this path is interpreted as relative to the home directory of the user with the same name on the remote machine. If the remote user name is not given, the current user name is used. If the path on the remote machine contains special shell characters, it needs to be surrounded by a backslash (\), double quotation mark ("), or single quotation mark (') so that all shell metacharacters can be interpreted remotely. It is important to note that RCP does not prompt for a password, which executes the copy through the RSH command.
  • directory each file or directory parameter can be either a remote file name or a local file name. The remote file name has the following form: [Email protected]:path, where rname is the remote user name, Rhost is the remote computer name, and path is the

• Instance

  rcplocal_fileremote_hostname:remote_fileEnterrcpremote_hostname:remote_filelocal_fileEnter

SCP (Secure copy)

SCP Transfer is encrypted

• Command format: SCP [parameter] [original path] [Target path]
• command Parameters
  
  • -1 Force SCP command to use protocol SSH1
  • -2 Enforce SCP command using protocol SSH2
  • -4 Force SCP command to use only IPV4 addressing
  • -6 Forcing the SCP command to use only IPV6 addressing
  • -B uses batch mode (no transmission password or phrase is queried during transfer)
  • -C allows compression. (Pass the-c flag to SSH to turn on compression)
  • -P retains the original file's modification time, access time, and access rights.
  • -Q does not display the transfer progress bar.
  • -R recursively replicates the entire directory. The
  • -v verbose displays the output. SCP and SSH (1) will display debugging information for the entire process. This information is used to debug connections, authentication, and configuration issues.
  • -C cipher encrypts the data transfer with cipher, which is passed directly to SSH.
  • -F ssh_config Specifies an alternate SSH configuration file that is passed directly to SSH.
  • -I identity_file the key file that is used when transferring from the specified file, and this parameter is passed directly to SSH. The
  • -L limit limits the bandwidth that users can use, in kbit/s.
  • -O ssh_option If you are accustomed to using parameter passing in Ssh_config (5),
  • -P port Note is uppercase P, port is the port number specified for data transfer
  • -S prog RAM Specifies the program that is used to encrypt the transfer. This program must be able to understand the options for SSH (1).

• Instance

  • Replicating from a local server to a remote server

    scp local_file remote_username@remote_ip:remote_folder/fileremote_ip:

  • Copying from a remote server to a local server

    scp root@192.168.120.204:/opt/soft/nginx-0.5.38.tar.gz /opt/soft/

Route/traceroute/netstat/ss to Be Continued ...

Advanced Linux Commands