What Are the Common SSH Commands
In this article, we’ll introduce you to the common SSH commands that you’ll be using to control a server remotely.
Please note that, before using these commands, your server must be set up accept SSH connections and you must have connected to your server either using a terminal application or using PuTTY. For more information on how to set this up, please see one of the following articles on using SSH:
Important: It is very easy to make mistakes when using shell access. Make sure you have created a full backup of your files before attempting any changes.
Before using a command, you can check its documentation by entering the following:
man command
These are some of the common commands used in SSH, but not limited to:
Navigation Commands:
To change folders:
cd pathname/folder/subfolder
To go up one level in nested directories:
cd ../
To go to the root directory:
cd /
To return to the previous directory:
cd -
To show the directory you are currently working in:
pwd
To show the contents of the working directory:
ls -alh
File Commands:
To read the contents of a text file:
less filename
To show the last 10 lines of a file:
tail -f filename
To search the contents of files (for "example"):
grep "example" filename
To search all files and subdirectories in a directory (for "example"):
grep -R "example" directory/
To copy a file:
cp original-file-name.txt new-file-name.txt
To copy files between directories:
cp original-file-name.txt ../../newfolder/new-file-name.txt
To copy all files from one directory to another:
cp files/* ../end/
To move a file from one directory to another:
mv currentfolder/filename.txt ../newfolder/filename
To make a copy of a file with a new name in the working directory:
mv current-file-name.txt new-file-name.txt
To move a directory up one level:
mv folder/ ..
To change file permissions:
chmod 755 index.html
The 755 is the previous sample corresponds to specific permissions that files can have. Here is a list of those permissions:
7 = Read + Write + Execute
6 = Read + Write
5 = Read + Execute
4 = Read
3 = Write + Execute
2 = Write
1 = Execute
0 = All access denied
The first number is for the owner, second for the group, and third for everyone.
To change the owner of a file (be sure to replace "domainuser" with the appropriate user):
chown domainuser index.html
To change the group of a file (be sure to replace "groupname" with the appropriate group):
chgrp groupname index.html
To copy a file to a different directory:
cp file.txt folder/file.txt
To copy a file to the same directory
cp file.txt file.txt_old
To copy an entire directory:
cp -R folder folder2
To create or edit a file:
nano file.txt
To create a new file:
touch newfile.txt
To create a zip archive:
zip -r file-name.zip foldername
To unzip a zip archive:
unzip filename.zip
To create a tar.gz archive:
tar czvf archive.tar.gz directory-or-file/
To decompress a tar.gz archive:
tar -xzf archive.tar.gz
To back up a database:
mysqldump -u database_user -p database > backup.sql
To restore a database from a backup:
mysql -u database_user -p database < name_of_backup.sql
To delete a file (this must be confirmed by pressing the y key and pressing enter in response to the prompt that comes up):
rm file.txt_old
To delete a file without being prompted:
rm -rf file.txt_old
To delete an entire folder and all its subfolders and contents without being prompted:
rm -rf /old/folder
Important: This is irreversible. Be sure that you have created proper backups before using this command. We will NOT be able to reverse your deletions.
Server Commands:
To change the password for current user:
passwd
To change the password for another user:
passwd username
To log into MySQL:
mysql
To show currently active server processes:
ps -auxf
To show live processes and memory use:
top
To restart Apache (CentOS):
service httpd restart
To restart Apache (Debian):
service apache2 restart
If you need any further assistance, or if you have any questions, please let us know. We’d love to help!