ultrix man page for putenv

putenv(3)						     Library Functions Manual							 putenv(3)

Name
       putenv - change or add value to environment

Syntax
       int putenv (string)
       char *string;

Description
       The  string  points to a string of the form ``name=value.''  The subroutine makes the value of the environment variable name equal to value
       by altering an existing variable or creating a new one.	In either case, the string pointed to by string becomes part of  the  environment,
       so  altering  the string will change the environment.  The space used by string is no longer used once a new string-defining name is passed
       to

Diagnostics
       The subroutine returns nonzero if it was unable to obtain enough space via for an expanded environment, otherwise zero.

Warnings
       The subroutine manipulates the environment pointed to by and can be used in conjunction with However, envp (the third argument to main)	is
       not changed.
       This routine uses to enlarge the environment.
       After is called, environmental variables are not in alphabetical order.
       A  potential  error is to call with an automatic variable as the argument, then exit the calling function while string is still part of the
       environment.

See Also
       execve(2), getenv(3), malloc(3), environ(7)

																	 putenv(3)