NAME
	  putenv - change or add value to environment
SYNTAX
	  int putenv (string)
	  char *string;
DESCRIPTION
	  String points	to a string of the form	``name=value.''
	  Putenv 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
	  putenv.
DIAGNOSTICS
	  Putenv returns non-zero if it	was unable to obtain enough
	  space	via malloc for an expanded environment,	otherwise
	  zero.
SEE ALSO
	  exec(2), getenv(3C), malloc(3C), environ(5).
     WARNINGS
	  Putenv manipulates the environment pointed to	by environ,
	  and can be used in conjunction with getenv.  However,	envp
	  (the third argument to main) is not changed.
	  This routine uses malloc(3C) to enlarge the environment.
	  After	putenv is called, environmental	variables are not in
	  alphabetical order.
	  A potential error is to call putenv with an automatic
	  variable as the argument, then exit the calling function
	  while	string is still	part of	the environment.