Linux basic file directory operation commands
Display directory or file: displays the target list. It is a command with high utilization in Linux system The output information of ls command can be highlighted in color to partition different types of files
[root@localhost ~]# ls --help
Command syntax:[ ls [option] File or directory ]
-a #Show all files, including hidden files, along with With The documents are also listed
-A #Show all files, including hidden files, but do not list them With
-d #List directories only
-f #List results directly without sorting
-h #The file size is displayed as B KB MB
-i #Lists the Inode number of the file
-l #Display in long format
-n #List uid and gid
-S #Sort by file size (large files first, small files last)
-t #Sort by time (large date first, small date last)
-r #Reverse output of sorting results
-R #Recursively display directories and subdirectories
-Z #List SELinux security context
--full-time #List file details
--time=atime/ctime/mtime #Lists the specified time
Use the ls -lh parameter to query the directory details
[root@localhost ~]# ls -lh total 0 -rw-r--r--. 1 root root 0 Nov 13 09:36 admin drwxr-xr-x. 2 root root 6 Nov 13 09:36 lyshark Item 1: File permission bit Item 2: Reference count(file:Hard link directory:Number of subdirectories under directory) Item 3: Owner of the file(Owner->Here is root) Item 4: The group to which the file belongs(Genus group->Here is root) Item 5: file size(Default unit byte byte) Item 6: Last modification time Item 7: file name
Use LS - LH -- full time to display the detailed time information of file creation
[root@localhost ~]# ls -h --full-time total 0 -rw-r--r--. 1 root root 0 2018-11-13 09:36:25.172274787 -0500 admin drwxr-xr-x. 2 root root 6 2018-11-13 09:36:13.292275532 -0500 lyshark
Use ls -lhS to display the file and print it from large to small
[root@localhost ~]# ls -lhS total 0 drwxr-xr-x. 2 root root 6 Nov 13 09:36 lyshark -rw-r--r--. 1 root root 0 Nov 13 09:36 admin
Use ls -lhrS to display the file and print it from small to large
[root@localhost ~]# ls -lhrS total 0 -rw-r--r--. 1 root root 0 Nov 13 09:36 admin drwxr-xr-x. 2 root root 6 Nov 13 09:36 lyshark
Use ls -lZ to display the file and display the SeLinux security context
[root@localhost ~]# ls -lZ -rw-r--r--. root root unconfined_u:object_r:admin_home_t:s0 admin drwxr-xr-x. root root unconfined_u:object_r:admin_home_t:s0 lyshark
Directory jump and switch: switch the current working directory
[root@localhost ~]# cd --help
Command syntax:[ cd [option] catalogue ]
cd #Enter user home directory
cd ~ #Enter user home directory
cd - #Returns the directory where you were before entering this directory
cd .. #Return to parent directory
cd ../.. #Return to the upper two directories
cd !$ #Use the parameters of the previous command as cd parameters
Use cd ~ or cd to switch to the user's home directory
[root@localhost etc]# pwd /etc [root@localhost etc]# cd [root@localhost ~]# pwd /root
Using cd Switch to the previous directory
[root@localhost ~]# pwd /root [root@localhost ~]# cd .. [root@localhost /]# pwd /
Using cd.. / Switch to the upper two directories
[root@localhost sysconfig]# pwd /etc/sysconfig [root@localhost sysconfig]# cd ../.. [root@localhost /]# pwd /
Create new directory: the mkdir command is used to create a new directory or create some directories recursively.
[root@localhost ~]# mkdir --help
Syntax format:[ mkdir [option] New directory name ]
-v #Show creation process
-p #Create directory recursively
-Z #Set security context
-m #Set permissions when creating a directory
Create directories recursively using mkdir -p
[root@localhost ~]# mkdir -p /tmp/lyshark/lyshark [root@localhost ~]# ls -lh /tmp/lyshark/ total 0 drwxr-xr-x. 2 root root 6 Nov 13 09:56 lyshark
Set permissions when creating a directory using mkdir -m
[root@localhost ~]# mkdir -m 000 lyshark [root@localhost ~]# ls -lh total 0 d---------. 2 root root 6 Nov 13 10:02 lyshark
Create empty file: the touch command is used to create an empty file, press, or update the time tag of the existing file to the current time of the system.
[root@localhost ~]# touch --help
Syntax format:[ touch [option] file name ]
-a #Modify access time
-c #Modify the file time. If the file does not exist, no new file will be created
-m #Modify mtime only
-t #File modification time (touch -t 1806101012)
Use the touch command to create an empty file lysark. In the current directory txt.
[root@localhost ~]# ls -lh total 0 [root@localhost ~]# touch lyshark.txt [root@localhost ~]# ls -lh total 0 -rw-r--r--. 1 root root 0 Nov 13 10:32 lyshark.txt
Use the touch -t command to modify the file at 11:59 on November 3, 2015
[root@localhost ~]# ls -lh --full-time total 0 -rw-r--r--. 1 root root 0 2018-11-13 10:35:50.639051120 -0500 lyshark.txt [root@localhost ~]# touch -t 1511031159 lyshark.txt [root@localhost ~]# ls -lh --full-time total 0 -rw-r--r--. 1 root root 0 2015-11-03 11:59:00.000000000 -0500 lyshark.txt
Copy file or directory: the cp command is used to copy one or more source files or directories to the specified destination file or directory.
[root@localhost ~]# cp --help
Syntax format:[ cp [option] Source file or directory destination directory ]
-a #Equivalent to pdr
-d #Copy along with the properties of the linked file
-f #Force replication
-i #If the target file already exists, ask when overwriting
-p #Copy with file attributes (backup common)
-r #Recursive replication, used for directory replication
-s #Create soft connection on copy
-u #Copying is not prompted until the source file is updated
Use the cp -a command to copy the file, and copy the file of / etc / to the / tmp / directory
[root@localhost ~]# cp -a /etc/* /tmp/ [root@localhost ~]# ls -lh /tmp/ total 1.1M -rw-r--r--. 1 root root 16 Oct 13 12:37 adjtime -rw-r--r--. 1 root root 1.5K Jun 7 2013 aliases -rw-r--r--. 1 root root 12K Oct 13 12:39 aliases.db drwxr-xr-x. 2 root root 236 Oct 13 12:34 alternatives ....ellipsis....
Use the cp -s command to copy files and create a soft link from / etc/passwd to the / tmp / directory
[root@localhost ~]# cp -s /etc/passwd /tmp/ [root@localhost ~]# ls -lh /tmp/ total 0 lrwxrwxrwx. 1 root root 11 Nov 13 10:09 passwd -> /etc/passwd
Use cp -a command to copy multiple files at a time to the / tmp / directory
[root@localhost ~]# cp -a /etc/passwd /etc/shadow /tmp/ [root@localhost ~]# ls -lh /tmp/ total 8.0K -rw-r--r--. 1 root root 898 Oct 13 12:37 passwd ----------. 1 root root 714 Oct 13 12:37 shadow
Move file or directory: the mv command is used to rename the file or directory. If the file exists, it will be forced to update.
[root@localhost ~]# mv --help
Syntax format:[ mv [option] Source file or directory destination directory ]
-f #Forced movement
-i #Move interactively
-u #Source files are not moved until they are updated
Use the mv command to move / etc/passwd to the / tmp directory
[root@localhost ~]# mv /etc/passwd /tmp/ [root@localhost ~]# ls -lh /tmp/ total 4.0K -rw-r--r--. 1 0 root 898 Oct 13 12:37 passwd
Use the mv command to move multiple files at a time. Next, move / etc/passwd and / etc/shadow to the / tmp directory
[root@localhost ~]# mv /etc/passwd /etc/shadow /tmp/ [root@localhost ~]# ls -lh /tmp/ total 8.0K -rw-r--r--. 1 0 root 898 Oct 13 12:37 passwd ----------. 1 0 root 714 Oct 13 12:37 shadow
Use the mv command to rename the lysark in the current directory to linux
[root@localhost ~]# ls -lh total 0 drwxr-xr-x. 2 root root 6 Nov 13 10:19 lyshark [root@localhost ~]# mv lyshark/ linux [root@localhost ~]# ls -lh total 0 drwxr-xr-x. 2 root root 6 Nov 13 10:19 linux
Delete file or directory: the rm command can delete one or more files or directories in a directory, or delete a directory and all its subordinate files and subdirectories
[root@localhost ~]# rm --help
Syntax format:[ rm [option] File or directory ]
-f #Delete without warning
-r #Recursive deletion
-i #Prompt before deleting
-fr #Common collocation
Use the rm -fr command to delete the linux directory under the current directory
[root@localhost ~]# ls linux [root@localhost ~]# rm -fr linux/ [root@localhost ~]# ls
Use the rm -fr * command to delete all files in the specified folder using wildcards
[root@localhost lyshark]# ls 1 10 2 3 4 5 6 7 8 9 [root@localhost lyshark]# rm -fr * [root@localhost lyshark]# ls
Judge the type of file: the file command is used to detect the type of a given file. The file command checks the file in three processes: file system check, magic magic number check and language check
[root@localhost ~]# file --help
Syntax format:[ file [option] File or directory ]
-b #When the identification results are listed, the file name is not displayed
-c #Detailed display of instruction execution process
-f file name #Read and determine the format in the file at one time
-z #Query compressed package information
Use the file command to determine the format of / etc/passwd and / bin/bash files
[root@localhost ~]# file /etc/passwd /etc/passwd: ASCII text [root@localhost ~]# file /bin/bash /bin/bash: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=9a57e086388119ecd285c4d5c66823f3f3b68ab5, stripped
Use the file -z command to read lysark tar. GZ compressed package file properties
[root@localhost ~]# ls -lh total 9.4M -rw-r--r--. 1 root root 9.4M Nov 13 10:51 lyshark.tar.gz [root@localhost ~]# file -z lyshark.tar.gz lyshark.tar.gz: POSIX tar archive (GNU) , (gzip compressed data, from Unix, last modified: Tue Nov 13 10:51:13 2018)
Use the file -f command to read the specified line in the file and judge the file in turn
[root@localhost ~]# cat temp /etc/passwd /etc/shadow /bin/bash /bin/ls [root@localhost ~]# file -f temp /etc/passwd: ASCII text /etc/shadow: ASCII text /bin/bash: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=9a57e086388119ecd285c4d5c66823f3f3b68ab5, stripped /bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=ec3f3e5e8160c9917e8a4b896fe9044748472991, stripped
Query file status: the stat command is used to display file status information. The output information of the stat command is more detailed than that of the ls command.
[root@localhost ~]# stat --help
Syntax format:[ stat [option] File or directory ]
-L #Support symbolic connection
-f #Displays file system status instead of file status
-t #Output information in a concise manner
Use the stat command to query the information of / bin/bash file
[root@localhost ~]# stat /bin/bash File: '/bin/bash' Size: 964544 Blocks: 1888 IO Block: 4096 regular file Device: fd00h/64768d Inode: 50340311 Links: 1 Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:shell_exec_t:s0 Access: 2018-11-13 09:33:12.197999579 -0500 Modify: 2017-09-26 09:14:20.000000000 -0400 Change: 2018-10-13 12:32:43.377997461 -0400 Birth: -
Use the stat -f command to display system status information
[root@localhost ~]# stat -f /bin/bash
File: "/bin/bash"
ID: fd0000000000 Namelen: 255 Type: xfs
Block size: 4096 Fundamental block size: 4096
Blocks: Total: 4452864 Free: 4155020 Available: 4155020
Inodes: Total: 8910848 Free: 8877953
Create linked file: the ln command is used to create a connection for a file. You can create either a soft connection or a hard link.
[root@localhost ~]# ln --help
Syntax format:[ stat [option] File or directory ]
-L #Support symbolic connection
-d #Establish hard links to directories
-f #Force link
-i #Ask before overwrite
-s #Create a soft link
Use the ln command to establish a hard link
[root@localhost ~]# ls -lhi total 944K 33844798 -rwxr-xr-x. 1 root root 942K Sep 26 2017 bash [root@localhost ~]# ln bash bash_ln [root@localhost ~]# ls -lhi total 1.9M 33844798 -rwxr-xr-x. 2 root root 942K Sep 26 2017 bash 33844798 -rwxr-xr-x. 2 root root 942K Sep 26 2017 bash_ln
Use the ln -s command to create a soft link
[root@localhost ~]# ls -lhi total 944K 33844798 -rwxr-xr-x. 1 root root 942K Sep 26 2017 bash [root@localhost ~]# ln -s bash bash_link [root@localhost ~]# ls -lhi total 944K 33844798 -rwxr-xr-x. 1 root root 942K Sep 26 2017 bash 33959316 lrwxrwxrwx. 1 root root 4 Nov 13 11:06 bash_link -> bash
Text print command: cat file print scroll command, control parameter output.
[root@localhost ~]# cat --help
Syntax format:[ cat [option] file name ]
-b #Line numbers are listed, and blank lines are not labeled
-E #Display the closing line character $
-T #Show Tab key as ^ I
-n #Print out the line number
Use the cat -n command to label the text and print it
[root@localhost ~]# cat -n /etc/passwd
1 root:x:0:0:root:/root:/bin/bash
2 bin:x:1:1:bin:/bin:/sbin/nologin
3 daemon:x:2:2:daemon:/sbin:/sbin/nologin
4 adm:x:3:4:adm:/var/adm:/sbin/nologin
5 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
6 sync:x:5:0:sync:/sbin:/bin/sync
....ellipsis....
Use the cat -E command to display the text terminator $
[root@localhost ~]# cat -E /etc/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$ ....ellipsis....
Display opening text: the head command is used to display the contents at the beginning of the file. By default, the head command displays the first 10 lines of the file
[root@localhost ~]# head --help
Syntax format:[ head [option] file name ]
-c 10 #Display the first 10 characters
-n 10 #Show first 10 lines
-v #Always display header information of file name
-q #Do not display header information for file names
Use the head -c command to display the first 20 characters of the text
[root@localhost ~]# head -c 20 /etc/passwd root:x:0:0:root:/roo [root@localhost ~]#
Use the head -n command to display the first 3 lines of text
[root@localhost ~]# head -n 3 /etc/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
Display end text: the tail command is used to input the end content of the file. The tail command displays the end 10 lines of the specified file on the screen by default
[root@localhost ~]# tail --help
Syntax format:[ tail [option] file name ]
-c 10 #Last 10 characters displayed
-n 10 #Display the last 10 lines of the file
-f #Continuously monitor changes behind documents
--pid=PID #Used with - f to indicate that it ends after the process ID dies
Use the tail -n command to display the last 3 lines of text
[root@localhost ~]# tail -n 3 /etc/passwd postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin lyshark:x:1000:1000:lyshark:/home/lyshark:/bin/bash
Use the tail -f command to dynamically monitor a file
[root@localhost ~]# tail -f /var/log/messages Nov 13 10:01:01 localhost systemd: Starting Session 3 of user root. Nov 13 10:10:54 localhost kernel: e1000: ens32 NIC Link is Down Nov 13 10:10:58 localhost kernel: e1000: ens32 NIC Link is Up Nov 13 10:10:58 localhost NetworkManager[772]: <info> ....ellipsis....
Use the tail --pid=PID command to monitor a process
[root@localhost ~]# ps PID TTY TIME CMD 1404 pts/0 00:00:00 bash 11441 pts/0 00:00:00 ps [root@localhost ~]# [root@localhost ~]# tail --pid=1401 tail: warning: PID ignored; --pid=PID is useful only when following ....ellipsis....
Use the tail -n +5 command to start printing after the fifth line
[root@localhost ~]# tail -n +5 /etc/passwd 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 halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin ....ellipsis....
Use the tail -n +5 | head -n 3 command to start printing from the fifth line and print down 2 lines
[root@localhost ~]# tail -n +5 /etc/passwd |head -n 3 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
Output text in specified format: the nl command reads the file parameter. By default, the standard input calculates the line number in the input, and writes the calculated line number to the standard output
[root@localhost ~]# nl --help
Syntax format:[ nl [option] file name ]
-c 10 #Last 10 characters displayed
-b a #List line numbers, including spaces (similar to cat -n)
-b t #List line numbers, excluding spaces (similar to cat -n)
-n ln #The line number is displayed on the far left
-n rn #The line number is displayed on the far right
-n rz #The line number is displayed on the far right and supplemented with 0
-w #Specify the number of complement 0
Use the nl -b a command to print text labels (similar to cat -n)
[root@localhost ~]# nl -b a /etc/passwd
1 root:x:0:0:root:/root:/bin/bash
2 bin:x:1:1:bin:/bin:/sbin/nologin
3 daemon:x:2:2:daemon:/sbin:/sbin/nologin
4 adm:x:3:4:adm:/var/adm:/sbin/nologin
5 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
6 sync:x:5:0:sync:/sbin:/bin/sync
....ellipsis....
Use the nl -b a -n rz command to list and number the text, and fill in the space 0
[root@localhost ~]# nl -b a -n rz /etc/passwd 000001 root:x:0:0:root:/root:/bin/bash 000002 bin:x:1:1:bin:/bin:/sbin/nologin 000003 daemon:x:2:2:daemon:/sbin:/sbin/nologin 000004 adm:x:3:4:adm:/var/adm:/sbin/nologin 000005 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin ....ellipsis....
Use the nl -b a -n rz -w 3 command to list the text and give it a number, which is filled with 2 lines of 0
[root@localhost ~]# nl -b a -n rz -w 3 /etc/passwd 001 root:x:0:0:root:/root:/bin/bash 002 bin:x:1:1:bin:/bin:/sbin/nologin 003 daemon:x:2:2:daemon:/sbin:/sbin/nologin 004 adm:x:3:4:adm:/var/adm:/sbin/nologin 005 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin ....ellipsis....
Non plain text file printing: od used to output octal, hexadecimal or other format encoded bytes of the file. This command is mainly used to view the values saved in binary files
[root@localhost ~]# od --help
Syntax format:[ od [option] file name ]
-t a #Output using default characters
-t c #Output using ASCII characters
-t d #Use decimal output
-t f #Use floating point output
-t o #Use octal output
-t x #Use hexadecimal output
Use the od -t a command to output in the default format
[root@localhost ~]# od -t a /bin/cd 0000000 # ! / b i n / s h nl b u i l t i 0000020 n sp c d sp " $ @ " nl 0000032
Use the od -t c command to use ASCII output
[root@localhost ~]# od -t c /bin/cd 0000000 # ! / b i n / s h \n b u i l t i 0000020 n c d " $ @ " \n 0000032
Use the od -t x command to output the hex of the binary file.
[root@localhost ~]# od -t x /bin/cd 0000000 622f2123 732f6e69 75620a68 69746c69 0000020 6463206e 40242220 00000a22
Page through text: the command more/less is a text through view command.
[root@localhost ~]# more --help
Syntax format:[ more file name ]
Space #Like turning the next page
B #Turn up one page
Enter #scroll up one line
/character string #Find string down
:f #Show line numbers now
q or Q #sign out
[root@localhost ~]# less --help
Syntax format:[ less [option] file name ]
-e #Automatically exit after file display
-f #Force display file
-l #Ignore case differences when searching
-N #The line number is displayed at the beginning of each line
Space #Turn down one page
[pageup] #Turn up a page
/character string #Find string down
?character string #Find string up
q #sign out
File patching: patch the specified configuration file, generate the difference file through comparison, and enter the patch
[root@localhost ~]# diff --help
Syntax format:[ diff [option] Source file new file > *.patch ]
-a #Treat any document as a text document
-b #Ignore the difference caused by spaces
-B #Ignore the difference caused by blank lines
-I #Ignore case differences
-N #When comparing directories, if a file is only in one directory, it will be regarded as an empty file in the other directory
-r #When comparing directories, recursively compare subdirectories
-u #Use the same output format
[root@localhost ~]# diff -Naur /root/old /root/new > lyshark.patch #Generate patch file
[root@localhost ~]# patch -p2 old < lyshark.patch #Additional patching