node . js process . env Property
原文:https://www.geeksforgeeks.org/node-js-process-env-property/
process.env 属性是流程模块的内置应用编程接口，用于获取用户环境。
语法:
process.env
返回值:该属性返回包含用户环境的对象。
下面的例子说明了 process.env 属性在 Node.js 中的使用:
例 1:
// Node.js program to demonstrate the
// process.env Property
// Include process module
const process = require('process');
// Printing process.env property value
console.log(process.env);
输出:
{ ALLUSERSPROFILE: 'C:\\ProgramData',
APPDATA: 'C:\\Users\\gekcho\\AppData\\Roaming',
cmake: 'D:\\programfiles\\Cmake\\bin\\cmake.exe',
CommonProgramFiles: 'C:\\Program Files\\Common Files',
'CommonProgramFiles(x86)': 'C:\\Program Files (x86)\\Common Files',
CommonProgramW6432: 'C:\\Program Files\\Common Files',
COMPUTERNAME: 'gekchos_lappy',
ComSpec: 'C:\\Windows\\system32\\cmd.exe',
DriverData: 'C:\\Windows\\System32\\Drivers\\DriverData',
GTK_BASEPATH: 'C:\\Program Files (x86)\\GtkSharp\\2.12\\',
HADOOP_HOME:
'C:\\Users\\gekcho\\Downloads\\Compressed\\hadoop-3.1.0\\hadoop-3.1.0\\bin',
HOMEDRIVE: 'C:',
HOMEPATH: '\\Users\\gekcho',
JAVA_HOME: 'C:\\Java\\jdk1.8.0_201',
LOCALAPPDATA: 'C:\\Users\\gekcho\\AppData\\Local',
LOGONSERVER: '\\\\gekchos_lappy',
MAGICK_HOME: 'C:\\wamp64\\bin\\php\\php7.3.1\\ext\\ImageMagick',
NUMBER_OF_PROCESSORS: '4',
OneDrive: 'C:\\Users\\gekcho\\OneDrive',
OneDriveConsumer: 'C:\\Users\\gekcho\\OneDrive',
OS: 'Windows_NT',
Path:
'C:\\wamp64\\bin\\php\\php7.3.1\\ext\\ImageMagick;
C:\\Program Files (x86)\\Common Files\\Oracle\\Java\\javapath;
C:\\Windows\\system32;C:\\Windows;C:\\Windows\\System32\\Wbem;
C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\;
C:\\Windows\\System32\\OpenSSH\\;D:\\programfiles\\Git\\cmd;
D:\\programfiles\\Cmake\\bin;C:\\Program Files\\nodejs\\;
C:\\Users\\gekcho\\Downloads\\Compressed\\hadoop-3.1.0\\hadoop-3.1.0\\bin;
C:\\Java\\jdk1.8.0_201\\bin;
C:\\Users\\gekcho\\Downloads\\Compressed\\spark-2.4.4-bin-hadoop2.7\\bin;
C:\\Program Files (x86)\\GtkSharp\\2.12\\bin;
C:\\Users\\gekcho\\AppData\\Local\\Microsoft\\WindowsApps;
C:\\Users\\gekcho\\AppData\\Roaming\\npm',
PATHEXT: '.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC',
PROCESSOR_ARCHITECTURE: 'AMD64',
PROCESSOR_IDENTIFIER: 'Intel64 Family 6 Model 142 Stepping 9, GenuineIntel',
PROCESSOR_LEVEL: '6',
PROCESSOR_REVISION: '8e09',
ProgramData: 'C:\\ProgramData',
ProgramFiles: 'C:\\Program Files',
'ProgramFiles(x86)': 'C:\\Program Files (x86)',
ProgramW6432: 'C:\\Program Files',
PROMPT: '$P$G',
PSModulePath:
'C:\\Program Files\\WindowsPowerShell\\Modules;
C:\\Windows\\system32\\WindowsPowerShell\\v1.0\\Modules',
PUBLIC: 'C:\\Users\\Public',
python3:
'C:\\Users\\gekcho\\AppData\\Local\\Programs\\Python\\Python37-32\\python.exe',
SESSIONNAME: 'Console',
SPARK_HOME:
'C:\\Users\\gekcho\\Downloads\\Compressed\\spark-2.4.4-bin-hadoop2.7',
SystemDrive: 'C:',
SystemRoot: 'C:\\Windows',
TEMP: 'C:\\Users\\gekcho\\AppData\\Local\\Temp',
TMP: 'C:\\Users\\gekcho\\AppData\\Local\\Temp',
USERDOMAIN: 'gekchos_lappy',
USERDOMAIN_ROAMINGPROFILE: 'gekchos_lappy',
USERNAME: 'gekcho',
USERPROFILE: 'C:\\Users\\gekcho',
windir: 'C:\\Windows' }
范例 2:
// Node.js program to demonstrate the
// process.env Property
// Include process module
const process = require('process');
// Printing process.env property value
var no_env = 0;
// Calling process.env
var env = process.env;
// Itterating through all returned data
for (var key in env) {
// Print value
console.log(key + ":\t\t\t" + env[key]);
no_env++;
}
// Printing count
console.log("total no of values available = "
+ no_env);
// Accessing one by one
console.log("operating system: " + env['OS']);
console.log("alluserprofile: " + env['ALLUSERSPROFILE']);
console.log("public directory: " + env['PUBLIC']);
输出:
ALLUSERSPROFILE: C:\ProgramData
APPDATA: C:\Users\gekcho\AppData\Roaming
cmake: D:\programfiles\Cmake\bin\cmake.exe
CommonProgramFiles: C:\Program Files\Common Files
CommonProgramFiles(x86):C:\Program Files (x86)\Common Files
CommonProgramW6432: C:\Program Files\Common Files
COMPUTERNAME: gekchos_lappy
ComSpec: C:\Windows\system32\cmd.exe
DriverData: C:\Windows\System32\Drivers\DriverData
GTK_BASEPATH: C:\Program Files (x86)\GtkSharp\2.12\
HADOOP_HOME: C:\Users\gekcho\Downloads\Compressed\hadoop-3.1.0\hadoop-3.1.0\bin
HOMEDRIVE: C:
HOMEPATH: \Users\gekcho
JAVA_HOME: C:\Java\jdk1.8.0_201
LOCALAPPDATA: C:\Users\gekcho\AppData\Local
LOGONSERVER: \\gekchos_lappy
MAGICK_HOME: C:\wamp64\bin\php\php7.3.1\ext\ImageMagick
NUMBER_OF_PROCESSORS: 4
OneDrive: C:\Users\gekcho\OneDrive
OneDriveConsumer: C:\Users\gekcho\OneDrive
OS: Windows_NT
Path: C:\wamp64\bin\php\php7.3.1\ext\ImageMagick;
C:\Program Files (x86)\Common Files\Oracle\Java\javapath;
C:\Windows\system32;C:\Windows;
C:\Windows\System32\Wbem;
C:\Windows\System32\WindowsPowerShell\v1.0\;
C:\Windows\System32\OpenSSH\;D:\programfiles\Git\cmd;
D:\programfiles\Cmake\bin;C:\Program Files\nodejs\;
C:\Users\gekcho\Downloads\Compressed\hadoop-3.1.0\hadoop-3.1.0\bin;
C:\Java\jdk1.8.0_201\bin;
C:\Users\gekcho\Downloads\Compressed\spark-2.4.4-bin-hadoop2.7\bin;
C:\Program Files (x86)\GtkSharp\2.12\bin;
C:\Users\gekcho\AppData\Local\Microsoft\WindowsApps;
C:\Users\gekcho\AppData\Roaming\npm
PATHEXT: .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
PROCESSOR_ARCHITECTURE:AMD64
PROCESSOR_IDENTIFIER: Intel64 Family 6 Model 142 Stepping 9, GenuineIntel
PROCESSOR_LEVEL: 6
PROCESSOR_REVISION: 8e09
ProgramData: C:\ProgramData
ProgramFiles: C:\Program Files
ProgramFiles(x86): C:\Program Files (x86)
ProgramW6432: C:\Program Files
PROMPT: $P$G
PSModulePath: C:\Program Files\WindowsPowerShell\Modules;
C:\Windows\system32\WindowsPowerShell\v1.0\Modules
PUBLIC: C:\Users\Public
python3: C:\Users\gekcho\AppData\Local\Programs\Python\Python37-32\python.exe
SESSIONNAME: Console
SPARK_HOME: C:\Users\gekcho\Downloads\Compressed\spark-2.4.4-bin-hadoop2.7
SystemDrive: C:
SystemRoot: C:\Windows
TEMP: C:\Users\gekcho\AppData\Local\Temp
TMP: C:\Users\gekcho\AppData\Local\Temp
USERDOMAIN: gekchos_lappy
USERDOMAIN_ROAMINGPROFILE:gekchos_lappy
USERNAME: gekcho
USERPROFILE: C:\Users\gekcho
windir: C:\Windows
total no of values available = 46
operating system: Windows_NT
alluserprofile: C:\ProgramData
public directory: C:\Users\Public
例 3:
// Node.js program to demonstrate the
// process.env Property
// Include process module
const process = require('process');
// Printing process.env property value
var env = process.env;
console.log("operating system: " + env.OS);
console.log("alluserprofile: " + env.ALLUSERSPROFILE);
console.log("public directory: " + env.PUBLIC);
// Setting new data
env.gekcho = "gekcho custom data";
console.log("stored in env.gekcho: " + env.gekcho);
// Delete data
delete env.gekcho
console.log("stored in env.gekcho: " + env.gekcho);
输出:
operating system: Windows_NT
alluserprofile: C:\ProgramData
public directory: C:\Users\Public
stored in env.gekcho: gekcho custom data
stored in env.gekcho: undefined
注意:以上程序使用node filename.js命令编译运行。
参考:T2】https://nodejs.org/api/process.html#process_process_env
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