putenv(S-osr5)
putenv --
change or add value to environment
Syntax
cc . . . -lc
#include stdlib.h>
int putenv (const char *string);
Description
string
points to a string of the form
name = value.
The
putenv
function
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 changes the environment.
The space used by
string
is no longer used once a new string defining
name
is passed to
putenv.
Diagnostics
The
putenv
function
returns non-zero
if it was unable to obtain enough space
via
malloc
for an expanded environment,
otherwise zero.
Warnings
The
putenv
function
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.
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.
This routine uses
malloc(S-osr5)
to enlarge the environment.
See also
environ(M),
exec(S-osr5),
getenv(S-osr5),
malloc(S-osr5)
Standards conformance
putenv is conformant with:
X/Open Portability Guide, Issue 3, 1989
.
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 02 June 2005