Libraries and Floating Point Support Guide: getenv()
The getenv() function searches the environment list to find the environment variable name, and returns a pointer to the corresponding value string. The GNU-specific secure_getenv () function is just like getenv () except that it returns NULL in cases where "secure execution" is required. char *getenv(const char *name) Parameters. name − This is the C string containing the name of the requested variable. Return Value. This function returns a null-terminated string with the value of the requested environment variable, or NULL if that environment variable does not exist. Example. The following example shows the usage of getenv The getenv() function shall search the environment of the calling process (see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 8, Environment Variables) for the environment variable name if it exists and return a pointer to the value of the environment variable. If the specified environment variable cannot be found, a null pointer Apr 02, 2020 · getenv is not case sensitive in the Windows operating system. getenv and _putenv use the copy of the environment pointed to by the global variable _environ to access the environment. getenv operates only on the data structures accessible to the run-time library and not on the environment "segment" created for the process by the operating system. getenv() の実装はリエントラント (再入可能) であることを要求されていない。 getenv () の返り値により参照される文字列は静的に割り当てられてもよく、 文字列の内容は後続の getenv (), putenv (3), setenv (3), unsetenv (3) の呼び出しにより変更されることがある。 HTML rendering created 2020-07-14 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.
The getenv() function searches the environment list to find the environment variable name, and returns a pointer to the corresponding value string. getenv(3) - Linux man page Name
Man page — GETENV Man page — GETENV getenv 함수는, 환경 변수 name 의 현재의 값을 취득합니다. 변수 name 하지만 현재의 환경에 없는 경우는, null 포인터가 돌아갑니다. setenv 함수는, 환경 변수 name (을)를 현재의 환경 리스트에 삽입 또는 재설정합니다.
getenv - Hurricane Electric
System::getEnv - Get the value of an environment variable. SYNOPSIS String getEnv(String env) ARGUMENTS env The name of the environment variable DESCRIPTION Retrieves the value of an environment variable. This is often necessary in a web application as the web server will set environment variables in the program. Some of these headers are set