getenv

System.getenv()和System.getProperty() 的区别

由 我是研究僧i 提交于 2019-12-25 16:04:19
1.System.getenv() 方法是获取指定的环境变量的值。它有两种方法，一种是接收参数为任意字符串，当存在指定环境变量时即返回环境变量的值，否则返回null。另外一种是不接受参数，那么返回的是所有的环境变量。下面是它们的源码 （1）接收参数为任意字符串 public static String getenv(String name) { SecurityManager sm = getSecurityManager(); if (sm != null) { sm.checkPermission(new RuntimePermission("getenv."+name)); } return ProcessEnvironment.getenv(name); } （2）不接受参数 public static java.util.Map<String,String> getenv() { SecurityManager sm = getSecurityManager(); if (sm != null) { sm.checkPermission(new RuntimePermission("getenv.*")); } return ProcessEnvironment.getenv(); } 注意：环境变量的修改的两种情况：修改环境变量之后，如果受影响的是应用程序

how to override an environment variable for different test cases in nodeJS?

由 |▌冷眼眸甩不掉的悲伤 提交于 2019-12-24 10:42:24
问题 I am using dotenv to load the .env file, but I need to run the test cases for different values of a particular environment variable. But unfortunately, once loaded dotenv does not let me change the value of the env variable, I can not reset the value again. What could be an alternate approach for this? 回答1: You should have only those variables as environment variables that don't affect your code. For example, the database host, passwords, api keys etc. I suggest you that you make 3 env files

using getenv and env doesn't give the same results:

由 冷暖自知 提交于 2019-12-11 06:09:44
问题 I have a C program that prints every environmental variable, whose name is given by stdin. It prints variables such as $PATH, $USER but it doesn't see the environmental variables that i defined myself in the Linux shell... For instance, in ~.bashrc I exported MYTEST=test_is_working, then I sourced the bashrc (source ~/.bashrc). I expected the program to return test_is_working with getenv but it doesn't. #include <QCoreApplication> #include <stdio.h> #include <stdlib.h> int main(int argc, char

Using getenv function

由 …衆ロ難τιáo~ 提交于 2019-12-11 03:59:49
问题 I have a C program that prints every environmental variable, whose name is given by stdin. It prints variables such as $PATH, $USER but it doesn't see the environmental variables i define myself in the Linux shell... For instance, in bash I define my=4, and I expect the program to return 4 when I give the input "my". int main () { char * key = (char * )malloc(30); scanf("%s", key); if(getenv(key) != NULL) printf("%s\n", getenv(key)); else printf("NULL\n"); return 0; } What can I do in order

Java System.getEnv()

由 ♀尐吖头ヾ 提交于 2019-12-11 03:51:32
问题 In mac OSX and in Linux CentOS, I insert a new system environment variable (i.e. "MYAPP") using .bashrc & .bash_profile. I even restarted my laptop (mac) and my server (linux). When I use the command line "env", that environment variable showed with the correct value. But somehow every time I try to get it in a Java app (desktop app or web app or EJB or servlet any other java app) in either mac or linux, that environment variable ("MYAPP") is not retrieved. I tried to iterate through the

How to get Environment Variable from Shell in PHP/phpinfo()

由 戏子无情 提交于 2019-12-11 03:34:34
问题 I'm trying to use SendGrid's API for which I need to access an environment variable that I've added to my root directory using the following command. echo "export SENDGRID_API_KEY='YOUR_API_KEY'" > sendgrid.env echo "sendgrid.env" >> .gitignore source ./sendgrid.env This has created a sendgrid.env file in my root folder, added sendgrid.env to my .gitignore file, and added SENDGRID_API_KEY as an environment variable. However, PHP's getenv('SENDGRID_API_KEY') key is not returning anything, and

Why change in LD_LIBRARY_PATH at Runtime dosen't Reflect on the Executable once the Executable gets loaded

由 泪湿孤枕 提交于 2019-12-10 13:06:19
问题 I'm trying to change the LD_LIBRARY_PATH from my C++ program. I'm able to get its value using getenv("LD_LIBRARY_PATH") and set its value using setenv() (and I know that this is working, because when I call getenv("LD_LIBRARY_PATH") again, I get the updated value), but changing its value from inside the program isn't having any effect on it: I still get this error-message: Failed to Load the shared library file If I set the value before the executable gets loaded or the application is started

Spotipy - set CLIENT_ID and CLIENT_SECRET

由 巧了我就是萌 提交于 2019-12-08 10:05:19
问题 Where do I go to set CLIENT_ID and CLIENT_SECRET so it's not stored in my python script? The Spotipy documentation says the following, but I can't figure out where I need to go to input these environment variables. Where do I set os.getenv? if not client_id: client_id = os.getenv('SPOTIPY_CLIENT_ID') if not client_secret: client_secret = os.getenv('SPOTIPY_CLIENT_SECRET') if not client_id: raise SpotifyOauthError('No client id') if not client_secret: raise SpotifyOauthError('No client secret'

go语言工程制作dockerfile，并部署到docker

由 偶尔善良 提交于 2019-12-07 14:04:55
前言 众所周知云计算时代，是docker，kubernetes的天下。学习使用docker和kubernetes是必选的。当然这两个应用都是基于go语言的。所以云计算时代使用go语言写服务也是极好的。那么如何将go语言服务部署到docker容器呢？ 1.首先使用go语言实现基本http服务 使用echo标准库实现8080端口输出helloworld的服务。 import ( "github.com/labstack/echo" "log" "net/http" ) func main() { e := echo. New () e. GET ( "/" , handlerindex) log .Println( "starting echo" ) err := e.Start( ":8080" ) if err != nil { log .Fatal( "echo" , err ) } } func handlerindex(c echo.Context) error { log .Println( "hello world handlerindex" ) return c.JSON(http.StatusOK, `{ "hello" : "world" }`) } 2.dockerfile 制作 dockerfile 制作的源镜像我们可以在 hub.docker.com 找到

第4章 Linux环境（环境变量）

由 China☆狼群 提交于 2019-12-06 02:32:05
目录 环境变量简述 getenv和setenv 环境变量简述 UNIX规范为各种应用定义了许多标准环境变量，包括终端类型、默认的编辑器、时区等。C语言程序可以通过putenv和getenv函数来访问环境变量 #include <stdlib.h> char *getenv(const char *name); int putenv(const char *string); 环境由一组格式为"名字=值"的字符串组成.getenv函数以给定的名字搜索环境中的一个字符串，并返回与该名字相关的值。如果请求的变量不存在，它就返回null。如果变量存在但无关联值，它将运行成功并返回一个空字符串，即该字符串的第一个字节是null。由于getenv返回的字符串是存储在getenv提供的静态空间中，所以如果想进一步使用它，你就必须将它复制到另一个字符串中，以免它被后续的getenv所覆盖 putenv函数以一个格式为"名字=值"的字符串作为参数，并将该字符串加到当前环境中。如果由于可用内存不足而不能扩展环境，它会失败并返回-1.此时错误变量errno将被设置为ENOMEM getenv和setenv 紧接在main函数声明后的几行代码用于确保程序environ.c被正确调用，它只带有一个或两个参数： #include <stdlib.h> #include <stdio.h> #include
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