1$value = getenv("VARNAME");
2// returns FALSE if VARNAME does not exist
3
4$env_vars = getenv();
5// if no name is specified, an associative array
6// with all environment variables is returned
1putenv('NAME=VALUE');
2
3// NAME may contain whitespaces ->
4putenv('NAME=VALUE')
5// is not equivalent to
6putenv('NAME = VALUE')