getenv(3) Library Functions Manual getenv(3)NAME
getenv - Returns the value of an environment variable
Standard C Library (libc.so, libc.a)
const char *name);
Interfaces documented on this reference page conform to industry standards as follows:
getenv(): XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Specifies the name of an environment variable.
The getenv() function searches the environment list for a string of the form name=value, and returns a pointer to a string containing the
corresponding value for name.
The returned string should not be modified by the application, but may be overwritten by a subsequent call to the getenv() or putenv()
functions from the same thread.
The getenv() function returns a pointer to a string containing the value in the current environment if such a string is present. If such a
string is not present, a null pointer is returned.
Functions: putenv(3), clearenv(3)
Standards: standards(5) delim off
Check Out this Related Man Page
GETENV(3) Linux Programmer's Manual GETENV(3)NAME
getenv - get an environment variable
char *getenv(const char *name);
The getenv() function searches the environment list to find the environment variable name, and returns a pointer to the corresponding value
The getenv() function returns a pointer to the value in the environment, or NULL if there is no match.
SVr4, POSIX.1-2001, 4.3BSD, C89, C99.
The strings in the environment list are of the form name=value.
As typically implemented, getenv() returns a pointer to a string within the environment list. The caller must take care not to modify this
string, since that would change the environment of the process.
The implementation of getenv() is not required to be reentrant. The string pointed to by the return value of getenv() may be statically
allocated, and can be modified by a subsequent call to getenv(), putenv(3), setenv(3), or unsetenv(3).
SEE ALSO clearenv(3), putenv(3), setenv(3), unsetenv(3), environ(7)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2008-03-17 GETENV(3)
Below is an extract from man page of getenv(3c)
1> getenv() can be safely called from a multi-thread program.
2> However, care must still be taken when using getenv() and putenv(3C) in a multi-thread program.
3> These routines examine and modify the environment list.
4> This list is... (1 Reply)
There is a function in Perl named PerlEnv_getenv() which is equivalent to getenv() in C. It invokes the environment variable. It uses the library the library perlclib.How to define this library and use the Perl function? (3 Replies)