1TYPERULES(5F) TYPERULES(5F)
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6 typerules - HylaFAX file type identification and conversion rules
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9 Only three types of files are accepted by the HylaFAX server for trans‐
10 mission as facsimile: POSTSCRIPT® files, PDF files, and TIFF Class F
11 (bilevel Group 3-encoded) files. All other types of files must be con‐
12 verted to one of these three formats. The facsimile submission program
13 applies a set of rules against the contents of each input file to iden‐
14 tify the file's type and to figure out how to convert the file to a
15 format that is suitable for transmission. These rules are stored in
16 the file /etc/hylafax/typerules, an ASCII file that is patterned after
17 the /etc/magic file used by the System V file(1) program. However,
18 there are significant differences, noted below.
19 Type rules work by matching data patterns in a file; typically patterns
21 that appear in the first few bytes of the file (i.e. magic numbers).
22 There are two types of rules, primary rules and secondary rules. Sec‐
23 ondary rules specify additional rules to apply after a primary rule has
24 been matched. When secondary rules are used, rule scanning continues
25 up to the next primary type rule in the file.
26 Each rule consists of a set of whitespace-separated fields:
28 offset datatype match result command
29 If an line is terminated wth a backslash character, the entry is con‐
30 tinued on the next line with any leading whitespace characters com‐
31 pressed to a single space. Comments are marked with the ``#'' charac‐
32 ter; everything from to the end of the line is discarded. Secondary
33 rules have a ``>'' character in the first column of the line; primary
34 rules do not.
35 The fields in each rule entry are:
37 offset The byte offset in the file at which data should be extracted
39 and compared to a matching string or value.
40 datatype The type of data value to extract at the specified offset for
42 comparison purposes; one of: ``byte'' (8 bit unsigned num‐
43 ber), ``short'' (16 bit unsigned number), ``long'' (32 bit
44 unsigned number), ``filename'' (the name of the file),
45 ``string'' (an array of bytes), ``istring'' (a case-insensi‐
46 tive array of bytes), or ``ascii'' (an array of ASCII-only
47 bytes).
48 match The value and operation to use in matching; the value used is
50 based on the datatype field. If value is ``x'', then it is
51 interpreted to mean match anything; otherwise the following
52 operators are supported (where data is the value extracted
53 from the file and value is specified in the match field)
54 except for types ``filename'', ``string'', ``istring'', and
55 ``ascii'':
56 = data == value != data != value
57 > data > value < data < value
58 <= data <= value >= data >= value
59 & (data & value) == value ! (data & value) != value
60 ^ (data ^ value) != 0
61 If no operation is specified then ``='' is used.
63 For ``string'', ``istring'', and ``ascii'' no operator is allowed; the implicit
65 operation is always ``=''. In these cases, the field is terminated by
66 a tab or end of line, not by ``#'' or `` ''. Characters in the field have
67 their literal value; there are no C-style character escapes. For ``filename'' no
68 operator is allowed; the operation expects that the value is a regular expression
69 to positively match the supplied data.
70 result One of ``ps'', ``tiff'', or ``error'' (case insensitive).
72 The first two results specify whether the rule generates a
73 POSTSCRIPT file or a TIFF/F file (Group 3-encoded bilevel
74 data), respectively. The ``error'' result indicates that a
75 file is unsuitable for transmission and, if supplied for
76 transmission, should cause the job to be aborted with the
77 command field used in an error message.
78 command A command description that is expanded and passed to the
80 shell to convert the input file to the result format (suit‐
81 able for sending as facsimile). Before the string is passed
82 to the shell, it is scanned and the following ``%'' escape
83 codes are substituted for:
84 %i input file name
85 %o output file name
86 %r output horizontal resolution in pixels/mm
87 %R output horizontal resolution in pixels/inch
88 %v output vertical resolution in lines/mm
89 %V output vertical resolution in lines/inch
90 %f data format, ``1'' for 1-d encoding or ``2'' for 2-d encoding
91 %w page width in pixels
92 %W page width in mm
93 %l page length in pixels
94 %L page length in mm
95 %s page size by name
96 %F the directory where HylaFAX filter programs reside
97 %<x> the <x> character (e.g. ``%%'' results in ``%''
98 See below for example uses of these codes.
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101 The following rules are used to match the formats that are handled
102 directly by the server:
103 #offset datatype match result command
104 0 string %! ps # POSTSCRIPT
105 0 string %PDF ps # POSTSCRIPT by Ghostscript
106 0 short 0x4d4d tiff # big-endian TIFF
107 0 short 0x4949 tiff # little-endian TIFF
108 These rules are used to process the ASCII version of IRIS Inventor
110 database files while blocking the transmission of the binary format
111 variant:
112 #offset datatype match result command
113 0 string #Inventor V error IRIS Inventor file
114 >15 string binary error binary IRIS Inventor file
115 >15 string ascii ps %F/textfmt -fCourier-Bold -p11bp\
116 -U -q >%o <%i
117 This rule is typically the last entry in the file and is used to con‐
119 vert all unmatched ASCII data files to POSTSCRIPT:
120 #offset datatype match result command
121 0 ascii x ps %F/textfmt -fCourier-Bold -p11bp -U -q >%o <%i
122
124 It is much better to convert data that is to be transmitted to POST‐
125 SCRIPT because this data format permits the facsimile server to do the
126 final imaging according to the optimal transfer parameters (resolution,
127 binary encoding, etc.).
128 It might be better to allow secondary rules to augment a primary rule
130 rather than just replace them. This would allow, for example, command
131 line options to be selected based on file type.
132
134 sendfax(1), hylafax-client(1)
135 May 12, 1993 TYPERULES(5F)