Support environment variables in ini files

[jwatzman]

PHP supports INI settings such as

hhvm.server.thread_count = ${WEB_CONCURRENCY}

but HHVM doesn't appear to support that. It would be nice for services such as Heroku to automatically tweak values (and probably tons of other uses).

[dzuelke]

👍

[DmitrySoshnikov]

FYI: the OS environment variables in INI-files per se are supported in HHVM (e.g. you can test using parse_ini_file with some environment variable). It seems that we use a different path for parsing php.ini for server config.

CC @JoelMarcey

[jwatzman]

#4720 could have a similar problem (works with parse_ini_file but not when loaded at startup).

[pce]

i don't know if this is a similiar issue, but parse_ini_file throws a syntax error: unexpected $end in normal mode with escaped doublequotes dt = "\\\test.example.com\", while php would still accept/parse the string.

parse_ini_file($tempfile, true, INI_SCANNER_RAW); is compatible.

$tempfile = sys_get_temp_dir()."/tmp.ini";
$tempStr = file_put_contents ($tempfile, file_get_contents(
        "https://raw.githubusercontent.com/pear/Config_Lite/master/tests/test.cfg"
    )
);
$a = parse_ini_file($tempfile);
var_dump($a); // FALSE in hhvm

Contents of test.cfg:

filename = "test.cfg"
debug = true

[general]
lang = "de"
app.name = "ConfigTest"
app.version = "0.1.0"

[counter]
count = 2
; yes is also "boolish" 
has_counter = yes

[test array]
tries[0] = "12/09"
tries[1] = "12/10"
tries[2] = "11/07"

[server]
basepath = "/var/www"
dt = "\\\test.example.com\"
st = '\\\test.example.com\'