Linux commands, files and directories (Cp,pwd,mkdir,rmdir;ls,cp,rm,mv,basename,dirname;cat,tac,more,less,head,tail,touch,umask,chattr, File,which,locate,find)

1. Directory Operations:

(1) CD (Switch directory)

CD ~ Back to home directory

CD Back to home directory

Cd.. Back to top directory

CD-Go back to the directory just now

Cd/var/spool/mail Absolute Path

Cd.. /mqueue relative Path (written by/var/spool/mail to/var/spool/mqueue)

(2) PWD (show current directory)

PWD Displays the current directory

PWD-P Displays the current directory (does not display the data for the connected file, but displays the correct full path)

(3) mkdir (Create a new directory)

Mkdir-p Test1/test2/test3 Creating a multi-tiered catalog

MKDIR-M 777 test2 New Permissions 777 Directory

(4) RmDir (delete an empty directory)

RmDir Test Delete empty folder test

Rmdir-p TEST1/TEST2/TEST3 Delete Test1/test2/test3

2. File and Directory Management

(1) View file directory (LS)

Ls-a list all files, including hidden files

LS-A lists all files, including hidden files, not included. With the. Two directories

LS-D lists only the directory itself, not including the file data

LS-L lists long strings of data, including file attributes and permissions

Ls-r Sort by File size

Ls-t Sorting by Time

LS--color=never not display color (always display color, Auto automatically judge)

LS--full-time output in full time mode

(2) Copy, delete and move (CP,RM,MV)

Cp-a/var/log/wtmp wtmp_test Copy all of the file's features past

Cp/var/log/wtmp. Copy to current directory

Cp-i if the target file exists, the overwrite asks for the action

Cp-p is copied along with the file attributes

Replication of the Cp-r directory

cp-d If the source file is a property of a connection file, copy the connection file properties, not the connection file itself

Cp-s copy becomes a symbolic connection file

Rm-i Interactive mode, ask the user whether to operate before deleting

Rm-f ignore files that do not exist, no warning message appears

Rm-r Recursive deletion

Mv-f if the destination file exists, it will not be queried and overwritten directly

Mv-i if the destination file exists, ask whether to overwrite

Mv-u if the destination file exists and the source is newer, overwrite

(3) Get path file name and directory name

Basename/etc/systemd/network get the last file name (network)
Dirname/etc/systemd/network Get directory name (/ETC/SYSTEMD)

3. Document Content Review
(1) View the contents of the file directly
Cat starts displaying content from the first line

Cat-a full display with special characters

Cat-b List line numbers (blank lines do not mark line numbers)

Cat-n Print travel numbers (including blank lines)

TAC reverse display, contrary to cat

NL Add line number print

Nl-b A prints travel numbers (including blank lines), similar to Cat-n

Nl-b T If there is a blank line, the line number is not listed in the empty row

Nl-n Ln Row number on screen sitting side display

Nl-n RN line number is displayed to the right of the field without adding 0

Nl-n RZ line number appears to the right of the field, plus 0

Nl-w 3 line Number Default field changed to 3-bit

(2) Can flip view

More/etc/manpath.config View file information (Space page, enter key scroll down one line,/String down query,: F immediately display the file name and the current number of lines displayed, B back page, Q left)

Less/etc/manpath.config View file information (space/pageup up, pagedown down,/String down query,? query string up, n repeat query, n reverse repeat, Q left)

(3) Data selection

Head-n 10/etc/manpath.config Display the first 10 rows (without the-n 10 is also the default display of the first 10 lines)

Head-n -10/etc/manpath.config Display all previous lines, excluding the following 10 rows

Tail-n 20/etc/manpath.config Show last 20 rows

Tail-n +20/etc/manpath.config shows all subsequent lines, excluding the first 20 rows

Tail-f continuously detects the number of rows until CTRL + C is pressed

(4) Non-text files

Od-t a default character output

OD-T C ASCII character output

Od-t d decimal output (f floating point, o octal, x hex)

Od-t occ/etc/issue octal list of stored values and ASCII tables

(5) Modify the file time or create a new file

Touch test Create a new file test

Touch-a Modifying access times

Touch-c only modifies file time and does not create a new file if the file does not exist

Touch-m modifying Mtime

touch-d "2 days ago" test test file date adjusted to two day ago

TOUCH-T 1503151820 test test file time adjusted to 2015.3.15 18:20

4. Default permissions and Hidden permissions

Umask 002 Default Permissions Remove the W permission for other people's permissions

Chattr +i Test Sets the hidden properties of the test file (cannot be deleted, renamed, written to add data, only the root user can set)

Chattr +a Test Sets the hidden properties of the test file (only data can be added, cannot be deleted, modified, only the root user can set)

Chattr-a test cancels the hidden properties of the test file

LSATTR test show test File hidden properties

File Test View Files type

5. Command-and-file queries

Which ifconfig find the full file name of the Ifconfig command

Whereis ifconfig Looking for ifconfig this file

Locate ifconfig looking for files related to Ifconfig

Find/etc-mtime 3 3 days before the day the document was changed

Find/etc-mtime-3 documents changed within 3 days (excluding 3rd day)

Find/etc-mtime +3 3 days ago (excluding the 3rd day)

FIND/ETC-NEWER/ETC/PASSWD looking for/etc under passwd date new file and list

Find/-nouser Find files that are not owned by anyone in the system

Find/home-user root looking for files that belong to root under/home

Find/etc-name Test Search/etc file named Test

Find/-size +100k find files larger than 100k in the system

Find/-size +100k-exec ls-l {} \; List the files found above with Ls-l

Linux commands, files and directories (Cp,pwd,mkdir,rmdir;ls,cp,rm,mv,basename,dirname;cat,tac,more,less,head,tail,touch,umask,chattr, File,which,locate,find)