NETMOD Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Best Current Practice Q. Wu
Expires: September 11, 2019 Huawei Technologies
A. Farrel
Old Dog Consulting
B. Claise
Cisco Systems, Inc.
March 10, 2019
Handling Long Lines in Inclusions in Internet-Drafts and RFCs
draft-ietf-netmod-artwork-folding-01
Abstract
This document introduces a simple and yet time-proven strategy for
handling long lines in inclusions in drafts using a backslash ('\')
character where line-folding has occurred. The strategy works on any
text-based content, but is primarily intended for a structured
sequence of lines, such as would be referenced by the <sourcecode>
element defined in Section 2.48 of RFC 7991, rather than for two-
dimensional imagery, such as would be referenced by the <artwork>
element defined in Section 2.5 of RFC 7991. The approach produces
consistent results, regardless of the content, that is both self-
documenting and enables automated reconstitution of the original
content.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 11, 2019.
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Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Applicability Statement . . . . . . . . . . . . . . . . . . . 3
3. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
4. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Automated Folding of Long Lines in Text Content . . . . . 4
4.2. Automated Reconstitution of the Original Text Content . . 4
5. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Not Recommended for Graphical Artwork . . . . . . . . . . 5
5.2. Doesn't Work as Well as Format-Specific Options . . . . . 5
6. Folded Structure . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Header . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.2. Body . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7. Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Automated Folding . . . . . . . . . . . . . . . . . . . . 6
7.1.1. Manual Folding . . . . . . . . . . . . . . . . . . . 7
7.2. Automated Unfolding . . . . . . . . . . . . . . . . . . . 8
8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. Simple Example Showing Boundary Conditions . . . . . . . 9
8.2. Example Showing Multiple Wraps of a Single Line . . . . . 9
8.3. Example With Native Backslash . . . . . . . . . . . . . . 10
8.4. Example With Native Whitespace . . . . . . . . . . . . . 10
8.5. Example of Manual Wrapping . . . . . . . . . . . . . . . 10
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
11.1. Normative References . . . . . . . . . . . . . . . . . . 13
11.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. POSIX Shell Script . . . . . . . . . . . . . . . . . 15
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
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1. Introduction
[RFC7994] sets out the requirements for plain-text RFCs and states
that each line of an RFC (and hence of an Internet-Draft) must be
limited to 72 characters followed by the character sequence that
denotes an end-of-line (EOL).
Internet-Drafts and RFCs often include example text or code
fragments. In order to render the formatting of such text it is
usually presented as a figure using the "<sourcecode>" element in the
source XML. Many times the example text or code exceeds the 72
character line-length limit and the `xml2rfc` utility does not
attempt to wrap the content of such inclusions, simply issuing a
warning whenever lines exceed 69 characters. According to the RFC
Editor, there is currently no convention in place for how to handle
long lines, other than advising authors to clearly indicate what
manipulation has occurred.
This document introduces a simple and yet time-proven strategy for
handling long lines in inclusions in drafts using a backslash ('\')
character where line-folding has occurred. The strategy works on any
text based inclusion, but is primarily intended for a structured
sequence of lines, such as would be referenced by the <sourcecode>
element defined in Section 2.48 of [RFC7991], rather than for two-
dimensional imagery, such as would be referenced by the <artwork>
element defined in Section 2.5 of [RFC7991]. The approach produces
consistent results, regardless of the content, that is both self-
documenting and enables automated reconstitution of the original
content.
Note that text files are represent as lines having their first
character in column 1, and a line length of N where the last
character is in the Nth column and is immediately followed by an end
of line character sequence.
2. Applicability Statement
The format and algorithm defined in this document may be used in any
context, whether for IETF documents or in other situations where
structured folding is desired.
Within the IETF, this work is primarily targeted to xml2rfc v3
<sourcecode> element (Section 2.48 of [RFC7991]) and xml2rfc v2
<artwork> element (Section 2.5 of [RFC7749]) that, for lack of a
better option, is currently used for both source code and artwork.
This work may be also be used for the xml2rfc v3 <artwork> element
(Section 2.5 of [RFC7991]) but, as described in Section 5.1, it is
generally not recommended.
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3. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
4. Goals
4.1. Automated Folding of Long Lines in Text Content
Automated folding of long lines is needed in order to support draft
compilations that entail a) validation of source input files (e.g.,
XML, JSON, ABNF, ASN.1) and/or b) dynamic generation of output, using
a tool that doesn't observe line lengths, that is stitched into the
final document to be submitted.
Generally, in order for tooling to be able to process input files,
the files must be in their original/natural state, which may include
having some long lines. Thus, these source files need to be modified
before inclusion in the document in order to satisfy the line length
limits. This modification SHOULD be automated to reduce effort and
errors resulting from manual effort.
Similarly, dynamically generated output (e.g., tree diagrams) must
also be modified, if necessary, in order for the resulting document
to satisfy the line length limits. When needed, this effort again
SHOULD be automated to reduce effort and errors resulting from manual
effort.
4.2. Automated Reconstitution of the Original Text Content
Automated reconstitution of the original content is needed to support
validation of artwork extracted from documents. YANG [RFC7950]
modules are already extracted from Internet-Drafts and validated as
part of the draft-submission process. Additionally, there has been
some discussion regarding needing to do the same for instance
examples (i.e., XML/JSON documents) contained within Internet-Drafts
([yang-doctors-thread]). Thus, it SHOULD be possible to mechanically
reconstitute the original text content in order to satisfy tooling
input parsers.
5. Limitations
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5.1. Not Recommended for Graphical Artwork
While the solution presented in this document will work on any kind
of text-based content, it is most useful on content that represents
source code (XML, JSON, etc.) or, more generally, on content that has
not been laid out in two dimensions (e.g., diagrams).
Fundamentally, the issue is whether the text content remains readable
once folded. Text content that is unpredictable is especially
susceptible to looking bad when folded; falling into this category
are most UML diagrams, YANG tree diagrams, and ASCII art in general.
It is NOT RECOMMENDED to use the solution presented in this document
on graphical artwork.
5.2. Doesn't Work as Well as Format-Specific Options
The solution presented in this document works generically for all
text-based content, as it only views content as plain text. However,
various formats sometimes have built-in mechanisms that are better
suited to prevent long lines.
For instance, both the `pyang` and `yanglint` utilities have the
command line option "--tree-line-length" that can be used to indicate
a desired maximum line length for when generating tree diagrams
[RFC8340].
In another example, some source formats (e.g., YANG [RFC7950]) allow
any quoted string to be broken up into substrings separated by a
concatenation character (e.g., '+'), any of which can be on a
different line.
In yet another example, some languages allow factoring blocks of code
into call outs, such as functions. Using such call outs is
especially helpful when in some deeply-nested code, as they typically
reset the indentation back to the first column.
It is RECOMMENDED that authors do as much as possible within the
selected format to avoid long lines.
6. Folded Structure
Text content that has been folded as specified by this document MUST
contain the following structure.
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6.1. Header
The header is two lines long.
The first line is the following 46-character string that MAY be
surrounded by any number of printable characters. This first line
cannot itself be folded.
NOTE: '\\' line wrapping per BCP XX (RFC XXXX)
[Note to RFC Editor: Please replace XX and XXXX with the numbers
assigned to this document and delete this note. Please make this
change in multiple places in this document.]
The second line is a blank line. This line provides visual
separation for readability.
6.2. Body
The character encoding is the same as described in Section 2 of
[RFC7994], except that, per [RFC7991], tab characters are prohibited.
Lines that have a backslash ('\') occurring as the last character in
a line immediately followed by the end of line character sequence,
when the subsequent line starts with a backslash ('\') as the first
non-space (' ') character, are considered "folded".
Really long lines may be folded multiple times.
7. Algorithm
This section describes the processes for folding and unfolding long
lines when they are encountered in a single instance of text content.
It is assumed that another process inserts/extracts the individual
text content instances to/from an Internet-Draft or RFC. For
example, the `xiax` utility [xiax] does just this.
7.1. Automated Folding
Determine the desired maximum line length from input to the automated
line-wrapping process, such as from a command line parameter. If no
value is explicitly specified, the value "69" SHOULD be used.
Ensure that the desired maximum line length is not less than the
minimum header, which is 46 characters. If the desired maximum line
length is less than this minimum, exit (this text-based content
cannot be folded).
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Scan the text content for horizontal tab characters. If any
horizontal tab characters appear, either resolve them to space
characters or exit, forcing the input provider to convert them to
space characters themselves first.
Scan the text content to see if any line exceeds the desired maximum.
If no line exceeds the desired maximum, exit (this text content does
not need to be folded).
Scan the text content to ensure no existing lines already end with a
backslash ('\') character when the subsequent line starts with a
backslash ('\') character as the first non-space (' ') character, as
this would lead to an ambiguous result. If such a line is found,
exit (this text content cannot be folded).
If this text content needs to and can be folded, insert the header as
described in Section 6.1.
For each line in the text content, from top-to-bottom, if the line
exceeds the desired maximum, then fold the line at the desired
maximum column by 1) inserting the character backslash ('\')
character at the maximum column, 2) inserting the end of line
character sequence, inserting any number of space (' ') characters,
and 4) inserting a further backslash ('\') character.
The result of this previous operation is that the next line starts
with an arbitrary number of space (' ') characters, followed by a
backslash ('\') character, immediately followed by the character that
was previously in the maximum column.
Continue in this manner until reaching the end of the text content.
Note that this algorithm naturally addresses the case where the
remainder of a folded line is still longer than the desired maximum,
and hence needs to be folded again, ad infinitum.
The process described in this section is illustrated by the
"fold_it()" function in Appendix A.
7.1.1. Manual Folding
Authors may choose to fold text examples and source code by hand to
produce a text content that is more pleasant for a human reader but
which can still be automatically unfolded (as described in
Section 7.2) to produce single lines that are longer than the maximum
document line length.
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For example, an author may choose to make the fold at convenient gaps
between words such that the backslash is placed in a lower column
number than the text content's maximum column value.
Additionally, an author may choose to indent the start of a
continuation line by inserting space characters before the line
continuation marker backslash character.
Manual folding may also help handle the cases that cannot be
automatically folded as described in Section 7.
Authors MUST produce a result that adheres to the structure described
in Section 6.
7.2. Automated Unfolding
All unfolding is assumed to be automated although a reader will
mentally perform the act of unfolding the text to understand the true
nature of the original text content.
Scan the beginning of the text content for the header described in
Section 6.1. If the header is not present, starting on the first
line of the text content, exit (this artwork does not need to be
unfolded).
Remove the 2-line header from the text content.
For each line in the text content, from top-to-bottom, if the line
has a backslash ('\') character immediately followed by the end of
line character sequence, and if the next line has a backslash ('\')
character as the first non-space (' ') character, then the lines can
be unfolded. Remove the first backslash ('\') character, the end of
line character sequence, any leading space (' ') characters, and the
second backslash ('\') character, which will bring up the next line.
Then continue to scan each line in the text content starting with the
current line (in case it was multiply folded).
Continue in this manner until reaching the end of the text content.
The process described in this section is illustrated by the
"unfold_it()" function in Appendix A.
8. Examples
The following self-documenting examples illustrate folded text-based
content.
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The source text content cannot be presented here, as it would again
need to be folded. Alas, only the result can be provided.
The examples in Sections 8.1 through 8.4 were automatically folded on
column 69, the default value. Section 8.5 shows an example of manual
folding.
8.1. Simple Example Showing Boundary Conditions
This example illustrates a boundary condition test using numbers for
counting purposes. The input contains 5 lines, each line one
character longer than the previous.
Any printable character (including ' ' and '\') can be used as a
substitute for any number, except for on the 4th row, the trailing
'9' is not allowed to be a '\' character if the first non-space
character of the next line is a '\' character, as that would lead to
an ambiguous result.
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
123456789012345678901234567890123456789012345678901234567890123456
1234567890123456789012345678901234567890123456789012345678901234567
12345678901234567890123456789012345678901234567890123456789012345678
123456789012345678901234567890123456789012345678901234567890123456789
12345678901234567890123456789012345678901234567890123456789012345678\
\90
12345678901234567890123456789012345678901234567890123456789012345678\
\901
12345678901234567890123456789012345678901234567890123456789012345678\
\9012
8.2. Example Showing Multiple Wraps of a Single Line
This example illustrates one very long line (280 characters).
Any printable character (including ' ' and '\') can be used as a
substitute for any number.
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
12345678901234567890123456789012345678901234567890123456789012345678\
\9012345678901234567890123456789012345678901234567890123456789012345\
\6789012345678901234567890123456789012345678901234567890123456789012\
\3456789012345678901234567890123456789012345678901234567890123456789\
\01234567890
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8.3. Example With Native Backslash
This example has a '\' character in the wrapping column. The native
text includes the sequence "fish\fowl" with the '\' character
occurring on the 69th column.
string1="The quick brown dog jumps over the lazy dog which is a fish\
\\fowl as appropriate"
8.4. Example With Native Whitespace
This example has whitespace spanning the wrapping column. The native
input contains 15 space (' ') characters between "like" and "white".
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
Sometimes our strings include multiple spaces such as "We like \
\ white space."
8.5. Example of Manual Wrapping
This example was manually wrapped to cause the folding to occur after
each term, putting each term on its own line. Indentation is used to
additionally improve readability. Also note that the mandatory
header is surrounded by different printable characters than shown in
the other examples.
===== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) =====
<yang-library
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-library"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<module-set>
<name>config-modules</name>
<module>
<name>ietf-interfaces</name>
<revision>2018-02-20</revision>
<namespace>\
\urn:ietf:params:xml:ns:yang:ietf-interfaces\
\</namespace>
</module>
<module>
<name>ietf-ip</name>
<revision>2018-02-22</revision>
<namespace>\
\urn:ietf:params:xml:ns:yang:ietf-ip\
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\</namespace>
</module>
<import-only-module>
<name>ietf-yang-types</name>
<revision>2013-07-15</revision>
<namespace>\
\urn:ietf:params:xml:ns:yang:ietf-yang-types\
\</namespace>
</import-only-module>
<import-only-module>
<name>ietf-inet-types</name>
<revision>2013-07-15</revision>
<namespace>\
\urn:ietf:params:xml:ns:yang:ietf-inet-types\
\</namespace>
</import-only-module>
</module-set>
<schema>
<name>config-schema</name>
<module-set>config-modules</module-set>
</schema>
<schema>
<name>state-schema</name>
<module-set>config-modules</module-set>
<module-set>state-modules</module-set>
</schema>
<datastore>
<name>ds:startup</name>
<schema>config-schema</schema>
</datastore>
<datastore>
<name>ds:running</name>
<schema>config-schema</schema>
</datastore>
<datastore>
<name>ds:operational</name>
<schema>state-schema</schema>
</datastore>
<content-id>75a43df9bd56b92aacc156a2958fbe12312fb285</content-id>
</yang-library>
The manual folding produces a more readable result than the following
equivalent folding that contains no indentation.
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
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<yang-library
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-library"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<module-set>
<name>config-modules</name>
<module>
<name>ietf-interfaces</name>
<revision>2018-02-20</revision>
<namespace>urn:ietf:params:xml:ns:yang:ietf-interfaces</namesp\
\ace>
</module>
<module>
<name>ietf-ip</name>
<revision>2018-02-22</revision>
<namespace>urn:ietf:params:xml:ns:yang:ietf-ip</namespace>
</module>
<import-only-module>
<name>ietf-yang-types</name>
<revision>2013-07-15</revision>
<namespace>urn:ietf:params:xml:ns:yang:ietf-yang-types</namesp\
\ace>
</import-only-module>
<import-only-module>
<name>ietf-inet-types</name>
<revision>2013-07-15</revision>
<namespace>urn:ietf:params:xml:ns:yang:ietf-inet-types</namesp\
\ace>
</import-only-module>
</module-set>
<schema>
<name>config-schema</name>
<module-set>config-modules</module-set>
</schema>
<schema>
<name>state-schema</name>
<module-set>config-modules</module-set>
<module-set>state-modules</module-set>
</schema>
<datastore>
<name>ds:startup</name>
<schema>config-schema</schema>
</datastore>
<datastore>
<name>ds:running</name>
<schema>config-schema</schema>
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</datastore>
<datastore>
<name>ds:operational</name>
<schema>state-schema</schema>
</datastore>
<content-id>75a43df9bd56b92aacc156a2958fbe12312fb285</content-id>
</yang-library>
9. Security Considerations
This BCP has no Security Considerations.
10. IANA Considerations
This BCP has no IANA Considerations.
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
11.2. Informative References
[RFC7749] Reschke, J., "The "xml2rfc" Version 2 Vocabulary",
RFC 7749, DOI 10.17487/RFC7749, February 2016,
<https://www.rfc-editor.org/info/rfc7749>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC7991] Hoffman, P., "The "xml2rfc" Version 3 Vocabulary",
RFC 7991, DOI 10.17487/RFC7991, December 2016,
<https://www.rfc-editor.org/info/rfc7991>.
[RFC7994] Flanagan, H., "Requirements for Plain-Text RFCs",
RFC 7994, DOI 10.17487/RFC7994, December 2016,
<https://www.rfc-editor.org/info/rfc7994>.
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[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[xiax] "The `xiax` Python Package",
<https://pypi.org/project/xiax/>.
[yang-doctors-thread]
"[yang-doctors] automating yang doctor reviews",
<https://mailarchive.ietf.org/arch/msg/yang-doctors/
DCfBqgfZPAD7afzeDFlQ1Xm2X3g>.
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Appendix A. POSIX Shell Script
This non-normative appendix section includes a shell script that can
both fold and unfold text content. Note that this script is applied
only to single text content instances.
#!/bin/bash
print_usage() {
echo
echo "Folds the text file, only if needed, at the specified"
echo "column, according to BCP XX."
echo
echo "Usage: $0 [-c <col>] [-r] -i <infile> -o <outfile>"
echo
echo " -c: column to fold on (default: 69)"
echo " -r: reverses the operation"
echo " -i: the input filename"
echo " -o: the output filename"
echo " -d: show debug messages"
echo " -h: show this message"
echo
echo "Exit status code: zero on success, non-zero otherwise."
echo
}
# global vars, do not edit
debug=0
reversed=0
infile=""
outfile=""
maxcol=69 # default, may be overridden by param
hdr_txt="NOTE: '\\\\' line wrapping per BCP XX (RFC XXXX)"
equal_chars="=============================================="
space_chars=" "
fold_it() {
# since upcomming tests are >= (not >)
testcol=`expr "$maxcol" + 1`
# check if file needs folding
grep ".\{$testcol\}" $infile >> /dev/null 2>&1
if [ $? -ne 0 ]; then
if [[ $debug -eq 1 ]]; then
echo "nothing to do"
fi
cp $infile $outfile
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return -1
fi
foldcol=`expr "$maxcol" - 1` # for the inserted '\' char
# ensure input file doesn't contain a TAB
grep $'\t' $infile >> /dev/null 2>&1
if [ $? -eq 0 ]; then
echo
echo "Error: infile contains a TAB character, which is not"
echo "allowed."
echo
return 1
fi
# ensure input file doesn't contain the fold-sequence already
pcregrep -M "\\\\\n[\ ]*\\\\" $infile >> /dev/null 2>&1
if [ $? -eq 0 ]; then
echo
echo "Error: infile has a line ending with a '\' character"
echo " followed by a '\' character as the first non-space"
echo " character on the next line. This file cannot be"
echo " folded."
echo
return 1
fi
# center header text
length=`expr ${#hdr_txt} + 2`
left_sp=`expr \( "$maxcol" - "$length" \) / 2`
right_sp=`expr "$maxcol" - "$length" - "$left_sp"`
header=`printf "%.*s %s %.*s" "$left_sp" "$equal_chars"\
"$hdr_txt" "$right_sp" "$equal_chars"`
# fold using recursive passes ('g' didn't work)
if [ -z "$1" ]; then
# init recursive env
cp $infile /tmp/wip
fi
gsed "/.\{$testcol\}/s/\(.\{$foldcol\}\)/\1\\\\\n\\\\/" < /tmp/wip\
>> /tmp/wip2
diff /tmp/wip /tmp/wip2 > /dev/null 2>&1
if [ $? -eq 1 ]; then
mv /tmp/wip2 /tmp/wip
fold_it "recursing"
else
echo "$header" > $outfile
echo "" >> $outfile
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cat /tmp/wip2 >> $outfile
rm /tmp/wip*
fi
## following two lines represent a non-functional variant to the
## recursive logic presented in the block above. It used to work
## before the '\' on the next line was added to the format (i.e.,
## the trailing '\\\\' in the substitution below), but now there
## is an off-by-one error. Leaving here in case anyone can fix it.
#echo "$header" > $outfile
#echo "" >> $outfile
#gsed "/.\{$testcol\}/s/\(.\{$foldcol\}\)/\1\\\\\n\\\\/g"\
< $infile >> $outfile
return 0
}
unfold_it() {
# check if file needs unfolding
line=`head -n 1 $infile | fgrep "$hdr_txt"`
if [ $? -ne 0 ]; then
if [[ $debug -eq 1 ]]; then
echo "nothing to do"
fi
cp $infile $outfile
return -1
fi
# output all but the first two lines (the header) to wip (work
# in progress) file
awk "NR>2" $infile > /tmp/wip
# unfold wip file
gsed ":x; /.*\\\\\$/N; s/\\\\\n[ ]*\\\\//; tx; s/\t//g" /tmp/wip\
> $outfile
# clean up and return
rm /tmp/wip
return 0
}
process_input() {
while [ "$1" != "" ]; do
if [ "$1" == "-h" -o "$1" == "--help" ]; then
print_usage
exit 1
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fi
if [ "$1" == "-d" ]; then
debug=1
fi
if [ "$1" == "-c" ]; then
maxcol="$2"
shift
fi
if [ "$1" == "-r" ]; then
reversed=1
fi
if [ "$1" == "-i" ]; then
infile="$2"
shift
fi
if [ "$1" == "-o" ]; then
outfile="$2"
shift
fi
shift
done
if [ -z "$infile" ]; then
echo
echo "Error: infile parameter missing (use -h for help)"
echo
exit 1
fi
if [ -z "$outfile" ]; then
echo
echo "Error: outfile parameter missing (use -h for help)"
echo
exit 1
fi
if [ ! -f "$infile" ]; then
echo
echo "Error: specified file \"$infile\" is does not exist."
echo
exit 1
fi
min_supported=`expr ${#hdr_txt} + 8`
if [ $maxcol -lt $min_supported ]; then
echo
echo "Error: the folding column cannot be less than"
echo "$min_supported"
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echo
exit 1
fi
max_supported=`expr ${#equal_chars} + 1 + ${#hdr_txt} + 1\
+ ${#equal_chars}`
if [ $maxcol -gt $max_supported ]; then
echo
echo "Error: the folding column cannot be more than"
echo "$max_supported"
echo
exit 1
fi
}
main() {
if [ "$#" == "0" ]; then
print_usage
exit 1
fi
process_input $@
if [[ $reversed -eq 0 ]]; then
fold_it
code=$?
else
unfold_it
code=$?
fi
exit $code
}
main "$@"
Acknowledgements
The authors thank the following folks for their various contributions
(sorted by first name): Gianmarco Bruno, Italo Busi, Jonathan
Hansford, Joel Jaeggli, Lou Berger, Martin Bjorklund, Italo Busi, and
Rob Wilton.
The authors additionally thank the RFC Editor for confirming that
there is no set convention today for handling long lines in artwork/
sourcecode inclusions.
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Authors' Addresses
Kent Watsen
Watsen Networks
EMail: kent+ietf@watsen.net
Qin Wu
Huawei Technologies
EMail: bill.wu@huawei.com
Adrian Farrel
Old Dog Consulting
EMail: adrian@olddog.co.uk
Benoit Claise
Cisco Systems, Inc.
EMail: bclaise@cisco.com
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