Examples

Getting started

Attempt to load a system-wide configuration file, whose settings will be overwritten by a user preferences files.

Missing files are silently ignored.

from ihih import IHIH

conf = IHIH(
   (
      '/etc/example.conf',
      os.path.join(os.path.expanduser('~'), '.example.conf')
   ),
   debug='1'
)

if conf.get_float('debug', errors='ignore'):
   print 'i am running in debug mode'

Reloading the conf

Assuming conf is a IHIH instance.

# reload on SIGHUP
import signal

signal.signal(signal.SIGHUP, lambda s, f: conf.reload())

Configuration format

By default, IHIH parse files using the following rules:

• the key is before the first = character
• the value is everything after the first = character
• the value might be empty
• key and value have their leading and trailing spaces stripped
• values can be quoted (between ' or ")
• quoted values have their quotes automatically removed (ie: "my value" becomes my value)
• single quotes are considered as a character
• lines not matching the key / separator / value are ignored
• comments (beginning with a # or //) are ignored and deleted from the value except if they are escaped or quoted
• specials characters (\'"#/) can be escaped by prefixing them with a backslash (\) to not be treated specially
• other (non-special) characters preceded by the escape character are not treated specially and the escape character is preserved

By default, IHIHI parse files accordingly the following rules:

• same-same than IHIH
• add dollar ($) in the special character list
• every word prefixed by a non-escaped dollar and not embraced by single-quotes (') is considered as a variable
• strings beginning with ${ and ending with } are also variables, this let you define variables containing non-word characters such as dots hyphens, or spaces
• variables interpolation is done when using the variable, this let you define (or change) the variable content later
• when a variable is not found, it resolve as an empty string
• variable recursion resolve to an empty string

Which mean that it could parse, to a certain extent (see Single-line only), subset of:

• shell script
• Postfix main.cf
• Python
• INI (will ignore the sections)

That could be convenient if you have to share a configuration file between scripts, given you pay attention to respect both formats.

Examples of configuration files

Parsing a shell script:

# as in shell
FOO="bar"
FOOBAR=foo-$FOO   # resolve as: foo-bar
FOOBAR="foo-$FOO" # resolve as: foo-bar
FOOBAR='foo-$FOO' # resolve as: foo-$FOO
BAR=${FOO}        # resolve as: bar
ABC="a" 'b' c     # resolve as: a b c
C=hello # world   # resolve as: hello
D=hello \# world  # resolve as: hello # world

# different
DATE=$(date)      # resolve as: $(date)

Parsing a main.cf:

smtpd_banner = $myhostname ESMTP
myhostname = foo.example.net

Parsing some Python:

# same
a = 'AA'
b = "BB"

# notably different
c = 'A' "B"     # resolve as: A B
d = c           # resolve as: c

Parsing an INI file:

; section is ignored
[uwsgi]
http-socket = :9090
processes = 4

; different, resolve as: localhost:9000
URL = localhost${http-socket}