The pam_putenv() function sets the value of the PAM environment variable name equal to value either by altering an existing PAM variable or by creating a new one.

The name_value argument points to a string of the form name=value. A call to pam_putenv() does not immediately change the environment. All name_value pairs are stored in the PAM handle pamh. An application such as login(1) may make a call to pam_getenv(3PAM) or pam_getenvlist(3PAM) to retrieve the PAM environment variables saved in the PAM handle and set them in the environment if appropriate. login will not set PAM environment values which overwrite the values for SHELL, HOME, LOGNAME, MAIL, CDPATH, IFS, and PATH. Nor will login set PAM environment values which overwrite any value that begins with LD_.

If name_value equals NAME=, then the value associated with NAME in the PAM handle will be set to an empty value. If name_value equals NAME, then the environment variable NAME will be removed from the PAM handle.

The pam_putenv() function may return one of the following values:

PAM_SUCCESS

The function returned successfully.

PAM_OPEN_ERR

dlopen() failed when dynamically loading a service module.

PAM_SYMBOL_ERR

Symbol not found.

PAM_SERVICE_ERR

Error in service module.

PAM_SYSTEM_ERR

System error.

PAM_BUF_ERR

Memory buffer error.

PAM_CONV_ERR

Conversation failure.

PAM_PERM_DENIED

Permission denied.

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

dlopen(3DL), pam(3PAM), pam_getenv(3PAM), pam_getenvlist(3PAM), libpam(3LIB), attributes(5)

The interfaces in libpam are MT-Safe only if each thread within the multithreaded application uses its own PAM handle.