How do I get and set Environment variables in C

Question

How can I get Environnment variables and if something is missing  set the value

User · Answer

Get and Set  Get  string getEnv   Environment GetEnvironmentVariable  envVar      Set  string setEnv   Environment SetEnvironmentVariable  envvar   varEnv

User · Answer

Use the System Environment class   The methods  var value   System Environment GetEnvironmentVariable variable    Target     and   System Environment SetEnvironmentVariable variable  value    Target     will do the job for you    The optional parameter Target is an enum of type EnvironmentVariableTarget and it can be one of  Machine  Process  or User  If you omit it  the default target is the current process

User · Answer

Use the System Environment class   The methods  var value   System Environment GetEnvironmentVariable variable    Target     and   System Environment SetEnvironmentVariable variable  value    Target     will do the job for you    The optional parameter Target is an enum of type EnvironmentVariableTarget and it can be one of  Machine  Process  or User  If you omit it  the default target is the current process

User · Answer

Environment SetEnvironmentVariable  Variable name   value  EnvironmentVariableTarget User

User · Answer

I ran into this while working on a  NET console app to read the PATH environment variable  and found that using System Environment GetEnvironmentVariable will expand the environment variables automatically   I didn t want that to happen   that means folders in the path such as   SystemRoot  system32  were being re-written as  C  Windows system32    To get the un-expanded path  I had to use this   string keyName     SYSTEM CurrentControlSet Control Session Manager Environment    string existingPathFolderVariable    string Registry LocalMachine OpenSubKey keyName  GetValue  PATH       RegistryValueOptions DoNotExpandEnvironmentNames     Worked like a charm for me

User · Answer

Environment SetEnvironmentVariable  Variable name   value  EnvironmentVariableTarget User

User · Answer

This will work for an environment variable that is machine setting  For Users  just change to User instead    String EnvironmentPath   System Environment                  GetEnvironmentVariable  Variable Name   EnvironmentVariableTarget Machine

User · Answer

If the purpose of reading environment variable is to override the values in the appsetting json or any other config file  you can archive it through EnvironmentVariablesExtensions  var builder   new ConfigurationBuilder                    AddJsonFile  quot appSettings json quot                    AddEnvironmentVariables prefix   quot ABC  quot    var config   builder Build      According to this example  Url for the environment is read from the appsettings json  but when the AddEnvironmentVariables prefix   quot ABC  quot   line is added to the ConfigurationBuilder the value appsettings json will be override by in the environement varibale value

User · Answer

If the purpose of reading environment variable is to override the values in the appsetting json or any other config file  you can archive it through EnvironmentVariablesExtensions  var builder   new ConfigurationBuilder                    AddJsonFile  quot appSettings json quot                    AddEnvironmentVariables prefix   quot ABC  quot    var config   builder Build      According to this example  Url for the environment is read from the appsettings json  but when the AddEnvironmentVariables prefix   quot ABC  quot   line is added to the ConfigurationBuilder the value appsettings json will be override by in the environement varibale value

User · Answer

Use the System Environment class   The methods  var value   System Environment GetEnvironmentVariable variable    Target     and   System Environment SetEnvironmentVariable variable  value    Target     will do the job for you    The optional parameter Target is an enum of type EnvironmentVariableTarget and it can be one of  Machine  Process  or User  If you omit it  the default target is the current process

User · Answer

Use the System Environment class   The methods  var value   System Environment GetEnvironmentVariable variable    Target     and   System Environment SetEnvironmentVariable variable  value    Target     will do the job for you    The optional parameter Target is an enum of type EnvironmentVariableTarget and it can be one of  Machine  Process  or User  If you omit it  the default target is the current process

User · Answer

This will work for an environment variable that is machine setting  For Users  just change to User instead    String EnvironmentPath   System Environment                  GetEnvironmentVariable  Variable Name   EnvironmentVariableTarget Machine

User · Answer

I could be able to update the environment variable by using the following  string EnvPath   System Environment GetEnvironmentVariable  PATH   EnvironmentVariableTarget Machine     string Empty  if   string IsNullOrEmpty EnvPath   amp  amp   EnvPath  EndsWith           EnvPath   EnvPath        EnvPath   EnvPath     C  Test   Environment SetEnvironmentVariable  PATH   EnvPath   EnvironmentVariableTarget Machine

User · Answer

Get and Set  Get  string getEnv   Environment GetEnvironmentVariable  envVar      Set  string setEnv   Environment SetEnvironmentVariable  envvar   varEnv

User · Answer

I ran into this while working on a  NET console app to read the PATH environment variable  and found that using System Environment GetEnvironmentVariable will expand the environment variables automatically   I didn t want that to happen   that means folders in the path such as   SystemRoot  system32  were being re-written as  C  Windows system32    To get the un-expanded path  I had to use this   string keyName     SYSTEM CurrentControlSet Control Session Manager Environment    string existingPathFolderVariable    string Registry LocalMachine OpenSubKey keyName  GetValue  PATH       RegistryValueOptions DoNotExpandEnvironmentNames     Worked like a charm for me

User · Answer

I could be able to update the environment variable by using the following  string EnvPath   System Environment GetEnvironmentVariable  PATH   EnvironmentVariableTarget Machine     string Empty  if   string IsNullOrEmpty EnvPath   amp  amp   EnvPath  EndsWith           EnvPath   EnvPath        EnvPath   EnvPath     C  Test   Environment SetEnvironmentVariable  PATH   EnvPath   EnvironmentVariableTarget Machine

[c#] How do I get and set Environment variables in C#?

Examples related to c#

Examples related to .net

Examples related to .net-2.0

Examples related to environment-variables