DIALRULES(5F)DIALRULES(5F)NAMEdialrules - HylaFAX dial string processing rules
DESCRIPTION
A dial string specifies how to dial the telephone in order
to reach a destination facsimile machine, or similar
device. This string is supplied by a user with each out-
going facsimile job. User-supplied dial strings need to
be processed in two ways by the HylaFAX server processes:
to craft a canonical phone number for use in locating the
receiver's capabilities, and to process into a form suit-
able for sending to a modem. In addition client applica-
tions may need to process a dial string to formulate an
external form that does not include private information
such as a credit card access code. Phone number canoni-
calization and dial string preparation are done according
to dial string processing rules that are located in a file
specified in the server configuration file; see the Dial-
StringRules parameter in config(5F). The generation of an
externalized form for a dial string is done by rules that
optionally appear in /usr/contrib/lib/hylafax/dialrules on
client machines.
A dial string rules file is an ASCII file containing one
or more rule sets. A rule set defines a set of transfor-
mation rules that are sequentially applied to a dial
string. Each rule set is associated with an identifier,
with certain well-known identifiers being used by the fac-
simile server or client application. Each transformation
rule is a regular expression and a replacement string; the
regular expression is repeatedly applied to a dial string
and any matching substring is replaced by the replacement
string.
The syntax of a dial string rules file is as follows.
Comments are introduced with the ``!'' character and con-
tinue to the end of the current line. Identifiers are
formed from a leading alphabetic and any number of subse-
quent alpha-numeric characters. A rule set is of the
form:
Identifier := [
rule1
rule2
...
]
where rule1, rule2, and so on are transformation rules.
Line breaks are significant. The initial rule set defini-
tion line and the trailing ``]'' must be on separate
lines; and each transformation rule must also be on a sin-
gle line. Transformation rules are of the form:
regular-expression = replacement
where regular-expression is a POSIX 1003.2 extended regu-
lar expression and replacement is a string that is substi-
tuted in place of any portion of the dial string that is
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matched by the regular-expression. White space is signif-
icant in parsing transformation rules. If a regular
expression or replacement string has embedded white space
in it, then the white space needs to be escaped with a
``\'' character or the entire string should be enclosed in
quote (``"'') marks. Replacement strings may reference
the entire string matched by the regular expression with
the ``&'' character. Substrings matched with the
``(...)'' constructs may be referenced by using ``\n''
where n is a single numeric digit between 1 and 9 that
refers to the n-th matched substring; c.f. re_format(7),
sed(1), etc.
To simplify and parameterize the construction of rule
sets, dial string rules files may also include simple
text-oriented variable definitions. A line of the form:
foo=string
defines a variable named foo that has the value string.
String values with embedded whitespace must use the ``\''
character or be enclosed in quote marks. Variables are
interpolated into transformation rules by referencing them
as:
${var}
Note that variable interpolation is done only once, at the
time a transformation rule is defined. This means that
forward references are not supported and that circular
definitions will not cause loops. The facsimile server
automatically defines four variables to have the values
defined in its configuration file: AreaCode, CountryCode,
LongDistancePrefix, and InternationalPrefix These vari-
ables are initialized before parsing a dial string rules
file; thus if they are defined in the rules file then they
will override any definition by the server.
There are three well known rule set names: CanonicalNumber
to convert a dial string to a canonical format, DialString
to prepare a dial string before using it to dial the tele-
phone, and DisplayNumber to convert a dial string to an
external ``displayable'' form that does not include the
private information that might appear in the raw dial
string.
EXAMPLES
This is the default set of rules for transforming a dial
string into a canonical phone number:
Area=${AreaCode} ! local area code
Country=${CountryCode} ! local country code
IDPrefix=${InternationalPrefix} ! prefix for placing an international call
LDPrefix=${LongDistancePrefix} ! prefix for placing a long distance call
!
! Convert a phone number to a canonical format:
!
! +<country><areacode><rest>
!
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! by (possibly) stripping off leading dialing prefixes for
! long distance and/or international dialing.
!
CanonicalNumber := [
#.* = ! strip calling card stuff
[abcABC] = 2 ! these convert alpha to numbers
[defDEF] = 3
[ghiGHI] = 4
[jklJKL] = 5
[mnoMNO] = 6
[prsPRS] = 7
[tuvTUV] = 8
[wxyWXY] = 9
[^+0-9]+ = ! strip white space etc.
^${IDPrefix} = + ! replace int. dialing code
^${LDPrefix} = +${Country} ! replace l.d. dialing code
^[^+] = +${Country}${Area}& ! otherwise, insert canon form
]
The first rule simply strips anything following a ``#'';
this will remove any calling card-related information.
The next eight rules convert upper and lower case alpha-
betics to the equivalent key numbers (this is convenient
for users that use mnemonic phone numbers). The tenth
rule removes everything but numbers and plus signs. The
eleventh rule translates any explicit international dial-
ing prefix into the ``+'' symbol used to identify country
codes. The twelfth rule replaces a leading long distance
dialing prefix with the local country code string. The
last rule matches local phone numbers and inserts the
local country code and area code.
As an example, assume that
AreaCode=415
CountryCode=1
InternationalPrefix=011
LongDistancePrefix=1
then if the above set of rules is applied to
``01123965-Tube#2345'', the transformations would be:
01123965-Tube#2345 01123965-Tube ! strip calling card stuff
01123965-Tube 01123965-8823 ! convert alphabetics
01123965-8823 011239658823 ! strip white space etc.
011239658823 +239658823 ! replace int. dialing code
+239658823 +239658823 ! replace l.d. dialing code
+239658823 +239658823 ! otherwise, insert canon form
for a final result of ``+239658823''.
SEE ALSOsendfax(1), dialtest(8C), faxq(8C), faxsend(8C),
faxgetty(8C), config(5F)
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