setenv(3C)						   Standard C Library Functions 						setenv(3C)

NAME

       setenv - add or change environment variable

SYNOPSIS

       #include <stdlib.h>

       int setenv(const char *envname, const char *envval,
	    int overwrite);

DESCRIPTION

       The  setenv()  function updates or adds a variable in the environment of the calling process.  The envname argument points to a string con-
       taining the name of an environment variable to be added or altered. The environment variable is set to the value to  which  envval  points.
       The  function  fails  if  envname  points to a string which contains an '=' character. If the environment variable named by envname already
       exists and the value of overwrite is non-zero, the function returns successfully and the environment is updated. If the	environment  vari-
       able  named  by	envname  already  exists and the value of overwrite is zero, the function returns successfully and the environment remains
       unchanged.

       If the application modifies environ or the pointers to which it points, the behavior  of  setenv()  is  undefined.  The	setenv()  function
       updates the list of pointers to which environ points.

       The strings described by envname and envval are copied by this function.

RETURN VALUES

       Upon  successful  completion,  0  is  returned.	Otherwise,  -1	is  returned, errno set to indicate the error, and the environment is left
       unchanged.

ERRORS

       The setenv() function will fail if:

       EINVAL	 The envname argument is a null pointer, points to an empty string, or points to a string containing an '=' character.

       ENOMEM	 Insufficient memory was available to add a variable or its value to the environment.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       getenv(3C), unsetenv(3C), attributes(5), standards(5)

SunOS 5.11							    31 Mar 2002 							setenv(3C)