If you know, skip it.<\/strong> <\/i><\/a><\/div>\n\n\n\nEnvironment variables are constants used by the operating system and applications installed in the operating system. They are usually written in capital letters.<\/p>\n\n\n\n
Since it is used many times and in many different places, and defining the values one by one is tedious, we will define it as a variable<\/span><\/strong> in the OS environment<\/span><\/strong>.<\/p>\n\n\n\nThe OS or application will retrieve the value from the environment variable and refer to it when needed.<\/p>\n\n\n\n
PATH is a special kind of environment variable.<\/h3>\n\n\n\n
Among the environment variables, PATH is a little different: PATH defines the commands of the program you want to run from any location.<\/p>\n\n\n\n
(A command that can be run from any directory.)<\/p>\n\n\n\n
For example, the command \"php\", which executes PHP, will result in an error if it is not added to the PATH environment variable.<\/p>\n\n\n\n
In order to run the php command, you have to do the following<\/p>\n\n\n\n
<\/div>
\/usr\/bin\/php<\/code><\/pre>\n\n\n\n'\/usr\/bin\/php' is the full path where the php command is installed.<\/p>\n\n\n\n
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'\/usr\/bin' is the default installation directory for application execution commands in Unix and Linux-based operating systems, and is added to the PATH system environment variable.<\/p>\n\n\n\n
In fact, php commands in '\/usr\/bin' can be executed as \"php\" without changing the PATH.<\/p>\n<\/div>\n\n\n\n
PATH is a shortcut for the command<\/h3>\n\n\n\n
This is a hassle. Each time you run a command, you have to type a long command.<\/p>\n\n\n\n
The solution to this hassle is PATH, which allows you to enter commands as usual by adding \"\/usr\/bin\/\" to the PATH value.<\/p>\n\n\n\n
<\/div>
php<\/code><\/pre>\n\n\n\nIt allows commands to be executed from any location. This is the reason why we set the PATH regardless of the programming language.<\/p>\n\n\n\n
\n
- java<\/li>
- php<\/li>
- python<\/li><\/ul>\n<\/div>\n\n\n\n
These are the commands that are always executed in program development. And the program source files are freely placed and worked on anywhere by the user.<\/p>\n\n\n\n
The PATH is there to make it easy to run commands from that freely placed source location.<\/p>\n\n\n\n
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There are two types of environment variables: system environment variables that are used by the entire OS, and user environment variables that can only be used by specific users.<\/p>\n\n\n\n
System environment variables can be used by all users.<\/p>\n<\/div>\n\n\n\n
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In Windows, when referring to an environment variable,<\/p>\n\n\n\n
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%PATH%<\/p>\n<\/div>\n\n\n\n
On Mac, Linux, and Unix,<\/p>\n\n\n\n
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$PATH<\/p>\n<\/div>\n\n\n\n
These are the rules.<\/p>\n<\/div>\n\n\n\n
PATH settings for Mac and Linux<\/h2>\n\n\n\n
There are two ways to set the PATH: Windows and other.<\/p>\n\n\n\n
macOS was developed based on Unix, and Linux was also inspired by Unix, so they are very similar.<\/p>\n\n\n\n
So Mac and Linux will work the same.<\/p>\n\n\n\n
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The name \"Linux\" comes from \"like a Unix\", which started as an imitation of Unix and spread to surpass the original Unix before long.<\/p>\n<\/div>\n\n\n\n
PATH settings for Mac and Redhat-based Linux<\/h3>\n\n\n\n
Mac and Redhat Linux (CentOS, Fedora, etc.) are internally made up of a collection of commands called bash.<\/p>\n\n\n\n
The way to set the PATH follows the rules of bash. There is one file to edit, .bash_profile.<\/p>\n\n\n\n
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.bash_profile is a hidden file in the home directory of the root user and each user.<\/p>\n\n\n\n
Hidden files cannot be seen without the -a option of the ls command.<\/p>\n\n\n\n
<\/div>
ls -altr<\/code><\/pre>\n<\/div>\n\n\n\n\n
The .bash_profile file for the root user is the system environment variable, and the files for other users are the user environment variable settings.<\/p>\n\n\n\n
The root user's file is rarely used for security reasons. Let's add it to the user environment variable.<\/p>\n<\/div>\n\n\n\n
.bash_profile before editing<\/div>
PATH=$PATH:$HOME\/.local\/bin:$HOME\/bin\nexport PATH<\/code><\/pre>\n\n\n\nThe .bash_profile already has this defined.<\/p>\n\n\n\n
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PATH=$PATH:<\/p>\n<\/div>\n\n\n\n
The colon (:) is a delimiter, meaning \"add to the already defined PATH\".<\/p>\n\n\n\n
When you add a new one, keep the one that was originally there and add it.<\/p>\n\n\n\n
Be careful not to delete the original description. This will cause the application to have some sort of problem.<\/p>\n\n\n\n
.bash_profile after editing<\/div>
PATH=$PATH:$HOME\/.local\/bin:$HOME\/bin:$HOME\/shell<\/code><\/pre>\n\n\n\n\n
\"PATH=$PATH:\" copies the system environment variables to the user environment variables.<\/p>\n\n\n\n
The one written after it is the original user environment variable.<\/p>\n<\/div>\n\n\n\n
This is all you need to edit the file. The last step is to reflect the edited contents to the OS.<\/p>\n\n\n\n
Update .bash_profile<\/div>
source ~\/.bash_profile<\/code><\/pre>\n\n\n\n\n
You don't need to run the source command, just log back in from the terminal and it will be reflected.<\/p>\n\n\n\n
However, if you run the source command, you don't need to re-login to the terminal.<\/p>\n<\/div>\n\n\n\n
PATH settings for Debian-based Linux and Unix<\/h3>\n\n\n\n
Debian-based Linux (such as Ubuntu) and Unix do not have bash as their default shell.<\/p>\n\n\n\n
So, the file to edit is not .bash_profile. It will be .profile.<\/p>\n\n\n\n
The only other difference is that the PATH definition is enclosed in double quotation marks (\").<\/p>\n\n\n\n
PATH definition in .profile<\/div>
PATH=\"$PATH:$HOME\/.local\/bin:$HOME\/bin\"<\/code><\/pre>\n\n\n\n\n
Some of them are not enclosed in double quotation marks as in bash. These rules should match the original definition.<\/p>\n<\/div>\n\n\n\n
Then, update the .profile with the source command and you are done.<\/p>\n\n\n\n
Update the .profile<\/div>
source ~\/.profile<\/code><\/pre>\n\n\n\nPATH settings for Windows<\/h2>\n\n\n\n
Windows has evolved in a unique way compared to other operating systems, so they do not work the same.<\/p>\n\n\n\n
It is faster to work on the desktop in Windows. Or rather, no one works with commands.<\/p>\n\n\n\n
Open the environment variable editing window.<\/h3>\n\n\n\n
First, open the environment variable editing window.<\/p>\n\n\n\n
Right-click on the PC (formerly My Computer) icon and select Properties.<\/p>\n\n\n\n
You should see a 'System' window. This can also be viewed in the 'System' section of the 'Control Panel'.<\/p>\n\n\n\n
You can also start the System in the Control Panel by typing \"System\" in the search box at the bottom left of the desktop.<\/p>\n\n\n\n
Next, select \"Advanced System Settings\" from the left menu.<\/p>\n\n\n\n
Press the 'Environment Variables' button in the 'Advanced' tab.<\/p>\n\n\n\n
Edit environment variables<\/h3>\n\n\n\n
When the Environment Variables window appears, double-click on the Path user environment variable, or select Path and click the Edit button.<\/p>\n\n\n\n
Then, press the New button and enter a path to add a new path.<\/p>\n\n\n\n
Finally, click the OK button to exit.<\/p>\n\n\n\n
That's all there is to it in Windows.<\/p>\n\n\n\n
In the past it was necessary to restart the PC, but now it is not necessary. If you reopen the command prompt, the PATH will be reflected.<\/p>\n\n\n\n
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If you look closely, you can see that only Windows is a little different.<\/p>\n\n\n\n