an environment list that can be freed using g_strfreev() (e.g., as returned from g_get_environ()), or NULL for an empty environment list. [allow-none][array zero-terminated=1][transfer full]
the environment variable to set, must not contain '='
the value for to set the variable to
whether to change the variable if it already exists
the updated environment list. Free it using g_strfreev(). [array zero-terminated=1][transfer full]
Sets the environment variable variable in the provided list envp to value. Both the variable's name and value should be in the GLib file name encoding. On UNIX, this means that they can be arbitrary byte strings. On Windows, they should be in UTF-8. Since 2.32