n this article you will learn most frequently used Basic Linux Commands with examples. We tried to cover as many Linux Commands as we can.
- 1 “COPY” Commands in Linux
- 2 File Commands
- 3 Linux Commands about Symlink
- 4 Linux Commands for Process Management
- 5 File Permissions
- 6 Briefing about Permissions in Linux
- 7 How to use “Find Command”
- 8 Linux Commands to check Word Count
- 9 Compression Commands (tar, tar.gz, tar.bz2 and zip
- 10 Linux Commands for Special Attributes on Files
- 11 Linux Commands to know System Information
- 12 Network Commands
- 13 SSH Commands
- 14 KeyBoard Shortcuts
- 15 Conclusion
“COPY” Commands in Linux
7. This command helps you copy one file to another
cp file1 file2
8. Copy all files of a directory within the current work directory
cp dir/* .
9. Copy a directory within the current work directory
cp -a /tmp/dir1 .
10. Copy a directory
cp -a dir1 dir2
11. Outputs the mime type of the file as text
cp file file1
1. The following Linux Command take you to the ‘/ home’ directory
2. This command go back one level
3. This command takes you two folders back.
4. This command take you to home directory
5. This command takes you to the user’s home directory
6. This command takes you to the previous directory
12. Linux Command to create a symbolic link to file or directory
ln -s file1 lnk1
13. Create a physical link to file or directory
ln file1 lnk1
14. View files of directory
15. View files of directory
16. Show details of files and directory
17. Show hidden files
18. Show files and directory containing numbers
19. Show files and directories in a tree starting from root
20. Create a directory called ‘dir1’
21. Create two directories simultaneously
mkdir dir1 dir2
22. Create a directory tree
mkdir -p /tmp/dir1/dir2
23. Move a file or directory
mv dir/file /new_path
24. Show the path of work directory
25. Delete file called ‘file1’
rm -f file1
26. Remove a directory called ‘dir1’ and contents recursively
rm -rf dir1
27. Remove two directories and their contents recursively
rm -rf dir1 dir2
28. Delete directory called ‘dir1’
30. Modify timestamp of a file or directory – (YYMMDDhhmm)
touch -t 0712250000 file1
31. Show files and directories in a tree starting from root(1)
Linux Commands for Process Management
32. The top command gives you information on the processes that currently exist.
33. The htop command is like top, but prettier and smarter.
34. Use the ps command to list running processes (top and htop list all processes whether active or inactive).
35. A step up from the simple ps command, pstree is used to display a tree diagram of processes that also shows relationships that exist between them.
36. The who command will display a list of all the users currently logged into your Linux system.
37. As its name suggests, kill can be used to terminate a process with extreme prejudice.
38. The pkill and killall commands can kill a process, given its name.
pkill & killall
39. pgrep returns the process IDs that match it.
40. With the help of nice command, users can set or change the priorities of processes in Linux.
41. It is similar to nice command. Use this command to change the priority of an already running process.
42. Gives the Process ID (PID) of a process
43. Gives free hard disk space on your system
44. Gives free RAM on your system
45. chmod the command for changing permissions
Syntax: chmod permission dir/file
chmod 755 Linux_Directory chmod 644 Linux_File
Different File Permissions
rwx rwx rwx = 111 111 111
rw- rw- rw- = 110 110 110
rwx --- --- = 111 000 000
rwx = 111 in binary = 7
rw- = 110 in binary = 6
r-x = 101 in binary = 5
r-- = 100 in binary = 4
7 = 4+2+1 (read/write/execute)
6 = 4+2 (read/write)
5 = 4+1 (read/execute)
4 = 4 (read)
3 = 2+1 (write/execute)
2 = 2 (write)
1 = 1 (execute)
Briefing about Permissions in Linux
There is a huge importance with Linux Commands when we discuss about Permissions. No restrictions on permissions. Anybody may do anything. Generally not a desirable setting.
The file’s owner may read, write, and execute the file. All others may read and execute the file. This setting is common for programs that are used by all users.
The file’s owner may read, write, and execute the file. Nobody else has any rights. This setting is useful for programs that only the owner may use and must be kept private from others.
All users may read and write the file.
The owner may read and write a file, while all others may only read the file. A common setting for data files that everybody may read, but only the owner may change.
The owner may read and write a file. All others have no rights. A common setting for data files that the owner wants to keep private.
How to use “Find Command”
The below Linux Commands gives you better Idea on find commands. You can also check more Find Commands in our other article too.
46. To find a file by name
find -name "File1"
47. To find a file by name, but ignore the case of the “File1”
find -iname "File1"
48. To search all files that end in “.conf”
find /path -type f -name "*.conf"
49. To find all files that are exactly 50 bytes
find /path -size 50c
50. To find all files less than 50 bytes
find /path -size -50c
51. To Find all files more than 700 Megabytes
find / -size +700M
52. To find files that have a modification time of a day ago
find / -mtime 1
53. To find files that were accessed in less than a day ago
find / -atime -1
54. To find files that last had their meta information changed more than 3 days ago
find / -ctime +3
55. To find files that were accessed in less than a minute ago
find / -mmin -1
56. If we want to match an exact set of permissions
find / -perm 644
57. If we want to specify anything with at least those permissions
find / -perm -644
Linux Commands to check Word Count
58. Prints the number of lines in a file.
wc -l file_name OR cat file_name | wc -l
59. Prints the number of words in a file.
60. Displays the count of bytes in a file.
61. Prints the count of characters from a file.
62. Prints only the length of the longest line in a file.
Compression Commands (tar, tar.gz, tar.bz2 and zip
Options to use the above Linux Commands
- c – create a archive file.
- x – extract a archive file.
- v – show the progress of archive file.
- f – filename of archive file.
- t – viewing content of archive file.
- j – filter archive through bzip2.
- z – filter archive through gzip.
- r – append or update files/directories to existing archive file.
- w – verify a archive file.
About TAR Command
63. To Create tar Archive File
tar -cvf compress.tar /path/directory
64. To List Content of tar Archive File
tar -tvf compress.tar
65. To Untar tar Archive File
tar -xvf compress.tar
66. To Untar tar Archive File in a specific directory
tar -xvf compress.tar -C /path/to diretory
67. Untar Single file from tar File
tar -xvf compress.tar file1.txt
68. Untar Multiple files from tar
tar -xvf compress.tar "file 1" "file 2"
69. Extract Group of Files using Wildcard from tar Archive
tar -xvf compress.tar --wildcards '*.txt'
70. To Add Files or Directories to tar Archive File
tar -rvf compress.tar file/dir
71. To Create tar.gz Archive File
tar -cvzf compresstar.gz /path/directory
72. To List Content tar.gz Archive File
tar -tvf compress.tar.gz
73. To Untar tar.gz Archive File
tar -zxvf compress.tar.gz
74. To Untar tar.gz Archive File in a specific directory
tar -zxvf compress.tar.gz -C /path/to diretory
75. Untar Single file from tar.gz File
tar -zxvf compress.tar.gz file1.txt
76. Untar Multiple files from tar.gz
tar -zxvf compress.tar.gz "file 1" "file 2"
77. Extract Group of Files using Wildcard from tar.gz Archive
tar -zxvf compress.tar.gz --wildcards '*.tzt'
78. To Add Files or Directories to tar.gz
tar -rvf compress.tar.gz file/dir
79. To Create tar.bz2 Archive File
tar -cvfj compress.tar.bz2 /path/directory
80. To List Content tar.bz2 Archive File
tar -tvf compress.tar.bz2
81. To Uncompress tar.bz2 Archive File
tar -xvf compress.tar.bz2
82. Untar Single file from tar.bz2 File
tar -jxvf compress.tar.bz2 file1.txt
83. Untar Multiple files from tar.bz2
tar -jxvf compress.tar.bz2 "file 1" "file 2"
84. Extract Group of Files using Wildcard from tar.bz2 Archive
tar -jxvf compress.tar.bz2 --wildcards '*.tzt'
85. To Add Files or Directories to tar.bz2
tar -rvf compress.tar.bz2 file/dir
86. To Verify tar, tar.gz and tar.bz2 Archive File
tar -tvfW cmpress.tar
Linux Commands for ZIP
ZIP (The extension .zip is not mandatory and this is useful only to identify the file zip file)
87. To zipping a file or folder.
zip compress.zip file1 file2 folder1
88. To Zip individual files to a zip archive
zip compress.zip file1 file2 file3
Zipping a folder is a tricky thing as by default zip will not zip entire folder content such as sub folders and files
89. To zip first level of folder content use * as shown below
zip compress.zip Folder/*
90. If there are sub folders and files in 1 folder, in order to zip all content of a folder use -r option
zip -r compress.zip Folder
91. To list all the files stored in a zip file. Any of the below commands can be used and they give the same results.
unzip -l compress.zip
zipinfo -1 compress.zip
92. To delete a file in an archive without extracting entire zip file.
zip -d compress.zip path/to/file
93. To extract your files from a zip folder.
94. To extract to a specific directory use -d option
unzip compress.zip -d /destination
95. To extract specific file from an archive
unzip compress.zip test.sh
Linux Commands for Special Attributes on Files
96. Allows write opening of a file only append mode
chattr +a file1
97. Allows that a file is compressed / decompressed automatically by the kernel
chattr +c file1
98. Makes sure that the program ignores Dump the files during backup
chattr +d file1
99. Makes it an immutable file, which can not be removed, altered, renamed or linked
chattr +i file1
100. Allows a file to be delete safely
chattr +s file1
101. Makes sure that if a file is modified changes are written in synchronous mode as with sync
chattr +S file1
102. Allows you to recover the contents of a file even if it is canceled
chattr +u file1
103. Show specials attributes on file/folder
Linux Commands to know System Information
104. To know only system name, you can use uname command
105. To view your network hostname
106. To get information about kernel-version
107. To get the information about your kernel release
108. To get the information about your kernel release
109. To print your machine hardware name
110. All this information can be printed at once. The below two commands gives same result.
111. Find out information about the Linux distribution and version
112. To gather information about file system partitions
113. To view mounted file systems.
114. To view information about your CPU architecture such as number of CPU’s, cores, CPU family model, CPU caches, threads, etc. Either of the two below commands gives same output.
115. To view information about block devices
Extract Information about Hardware Components using “dmidecode“
116. To print information about memory. You can get the similar output with all the below commands.
dmidecode -t memory
free or free -mt or free -gt
117. To print information about system
dmidecode -t system
118. To print information about BIOS
dmidecode -t bios
119. To print information about processor
dmidecode -t processor
120. To dump all hardware information
dmidecode | less
121. PING (Packet Internet Groper) command sends packet requests to the address you specify to test the connectivity between 2 nodes.
122. Ifconfig utility is used to configure network interface parameters. Mostly we use this command to check the IP address assigned to the system.
123. traceroute print the route packets take to network host. Destination host or IP is mandatory parameter to use this utility
traceroute website.com / IP
124. route command is the tool used to display or modify the routeing table.
125. dig (Domain Information Groper) is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name servers.
126. Whois To know the information about domain like
127. Host Command to find name to IP or IP to name
host hostname host 126.96.36.199
128. telnet connect destination host:port via a telnet protocol if connection establishes means connectivity between two hosts is working fine.
telnet website.com 80
130. Tracepath traces the path of the network to the destination you have provided. It attempts to list the series of hosts through which your packets travel on their way to a given destination.
131. nslookup is a program to query Internet domain name servers.
132. netstat command allows you a simple way to review each of your network connections and open sockets. netstat with head output is very helpful while performing web server troubleshooting.
133. scp allows you to secure copy files to and from another host in the network.
scp -r -P 22 (ssh port) user@source_hostname:/path/to/dir /destination/path
134. nmap is a very powerful command, which checks the opened port on the server.
nmap hostname -p 80
135. Connect to host as user
136. connect to host on port
ssh -p port user@host
137. Halts the current command
138. Stops the current command, resume with fg in the foreground or bg in the background
139. Log out of current session, similar to exit
140. Erases one word in the current line
141. Erases the whole line
142. Type to bring up a recent command. You need to type the first letter of the command you are searching for.
143. Log out of current session
Hope you will get better with the Linux Commands we covered in this article. Leave your comments in the below comment box.