NETMOD Working Group K. Watsen
Internet-Draft Juniper Networks
Intended status: Best Current Practice Q. Wu
Expires: April 19, 2019 Huawei Technologies
A. Farrel
Juniper Networks
B. Claise
Cisco Systems, Inc.
October 16, 2018
Handling Long Lines in Artwork in Internet-Drafts and RFCs
draft-kwatsen-netmod-artwork-folding-08
Abstract
This document introduces a simple and yet time-proven strategy for
handling long lines in artwork in drafts using a backslash ('\')
character where line-folding has occurred. The strategy works on any
text based artwork, but is primarily intended for sample text and
formatted examples and code, rather than for graphical artwork. The
approach produces consistent results regardless of the content and
uses a per-artwork header. The strategy is both self-documenting and
enables automated reconstitution of the original artwork.
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 April 19, 2019.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
Watsen, et al. Expires April 19, 2019 [Page 1]
Internet-Draft Handling Long Lines in Artwork October 2018
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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Automated Folding of Long Lines in Artwork . . . . . . . 3
3.2. Automated Reconstitution of Original Artwork . . . . . . 4
4. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Not Recommended for Graphical Artwork . . . . . . . . . . 4
4.2. Doesn't Work as Well as Format-Specific Options . . . . . 4
5. Folded Structure . . . . . . . . . . . . . . . . . . . . . . 5
5.1. Header . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2. Body . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Automated Folding . . . . . . . . . . . . . . . . . . . . 6
6.1.1. Manual Folding . . . . . . . . . . . . . . . . . . . 7
6.2. Automated Unfolding . . . . . . . . . . . . . . . . . . . 7
7. Considerations for xml2rfc v3 . . . . . . . . . . . . . . . . 8
8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. Simple Example Showing Boundary Conditions . . . . . . . 8
8.2. Example Showing Multiple Wraps of a Single Line . . . . . 9
8.3. Example With Native Backslash . . . . . . . . . . . . . . 9
8.4. Example With Native Whitespace . . . . . . . . . . . . . 9
8.5. Example of Manual Wrapping . . . . . . . . . . . . . . . 9
9. Security Considerations . . . . . . . . . . . . . . . . . . . 10
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
11.1. Normative References . . . . . . . . . . . . . . . . . . 10
11.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. POSIX Shell Script . . . . . . . . . . . . . . . . . 12
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
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
Watsen, et al. Expires April 19, 2019 [Page 2]
Internet-Draft Handling Long Lines in Artwork October 2018
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 "<artwork>" 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 artwork, simply issuing a warning
whenever artwork 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 using a backslash ('\') character where line-
folding has occurred. The strategy works on any text based artwork,
but is primarily intended for sample text and formatted examples and
code, rather than for graphical artwork. The approach produces
consistent results regardless of the content and uses a per-artwork
header. The strategy is both self-documenting and enables automated
reconstitution of the original artwork.
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. 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.
3. Goals
3.1. Automated Folding of Long Lines in Artwork
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
Watsen, et al. Expires April 19, 2019 [Page 3]
Internet-Draft Handling Long Lines in Artwork October 2018
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.
3.2. Automated Reconstitution of Original Artwork
Automated reconstitution of the original artwork 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 example YANG
fragments contained within Internet-Drafts ([yang-doctors-thread]).
Thus, it SHOULD be possible to mechanically reconstitute artwork in
order to satisfy the tooling input parsers.
4. Limitations
4.1. Not Recommended for Graphical Artwork
While the solution presented in this document will work on any kind
of text-based artwork, it is most useful on artwork that represents
sourcecode (XML, JSON, etc.) or, more generally, on artwork that has
not been laid out in two dimensions (e.g., diagrams).
Fundamentally, the issue is whether the artwork remains readable once
folded. Artwork that is unpredictable is especially susceptible to
looking bad when folded; falling into this category are most UML
diagrams.
It is NOT RECOMMENDED to use the solution presented in this document
on graphical artwork.
4.2. Doesn't Work as Well as Format-Specific Options
The solution presented in this document works generically for all
artwork, as it only views artwork as plain text. However, various
formats sometimes have built-in mechanisms that can be used 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
Watsen, et al. Expires April 19, 2019 [Page 4]
Internet-Draft Handling Long Lines in Artwork October 2018
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 chunks 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.
As such, it is RECOMMENDED that authors do as much as possible within
the selected format to avoid long lines.
5. Folded Structure
Artwork that has been folded as specified by this document MUST
contain the following structure.
5.1. 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.
5.2. 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".
Watsen, et al. Expires April 19, 2019 [Page 5]
Internet-Draft Handling Long Lines in Artwork October 2018
Really long lines may be folded multiple times.
6. Algorithm
6.1. Automated Folding
Determine the desired maximum line length from input. 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 artwork can not be
folded).
Scan the artwork to see if any line exceeds the desired maximum. If
no line exceeds the desired maximum, exit (this artwork does not need
to be folded).
Scan the artwork 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 artwork 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 artwork cannot be folded).
For each line in the artwork, 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 artwork. 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.
Watsen, et al. Expires April 19, 2019 [Page 6]
Internet-Draft Handling Long Lines in Artwork October 2018
6.1.1. Manual Folding
Authors may choose to fold text examples and source code by hand to
produce a document that is more pleasant for a human reader but which
can still be automatically unfolded (as described in Section 6.2) to
produce single lines that are longer than the maximum document line
length.
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 artwork'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 6.
6.2. 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 artwork or source code.
Scan the beginning of the artwork for the header described in
Section 5.1. If the header is not present, starting on the first
line of the artwork, exit (this artwork does not need to be
unfolded).
Remove the 2-line header from the artwork.
For each line in the artwork, 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 artwork starting with the
current line (in case it was multiply folded).
Continue in this manner until reaching the end of the artwork.
Watsen, et al. Expires April 19, 2019 [Page 7]
Internet-Draft Handling Long Lines in Artwork October 2018
7. Considerations for xml2rfc v3
[RFC7991] introduces the vocabulary for version 3 of the xml2rfc
tool. This includes a new element, "<sourcecode>" used to present
sourcecode examples and fragments and to distinguish them from
general artwork and in particular figures and graphics.
The folding and unfolding described in this document is applicable to
the "<artwork>" element in both v2 and v3 of xml2rfc, and is equally
applicable to the "<sourcecode>" element in xml2rfc v3.
8. Examples
The following self-documenting examples illustrate a folded document.
The source artwork 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
Watsen, et al. Expires April 19, 2019 [Page 8]
Internet-Draft Handling Long Lines in Artwork October 2018
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
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.
Watsen, et al. Expires April 19, 2019 [Page 9]
Internet-Draft Handling Long Lines in Artwork October 2018
[NOTE: '\\' line wrapping per BCP XX (RFC XXXX)]
<request>::= <RP> \
\<END-POINTS> \
\[<LSPA>] \
\[<BANDWIDTH>] \
\[<metric-list>] \
\[<RRO>[<BANDWIDTH>]] \
\[<IRO>] \
\[<LOAD-BALANCING>]
The manual folding produces a more readable result than the following
equivalent folding that contains no indentation.
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
<request>::= <RP> <END-POINTS> [<LSPA>] [<BANDWIDTH>] [<metric-list>\
\] [<RRO>[<BANDWIDTH>]] [<IRO>] [<LOAD-BALANCING>]
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
[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>.
Watsen, et al. Expires April 19, 2019 [Page 10]
Internet-Draft Handling Long Lines in Artwork October 2018
[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>.
[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>.
[yang-doctors-thread]
"[yang-doctors] automating yang doctor reviews",
<https://mailarchive.ietf.org/arch/msg/yang-doctors/
DCfBqgfZPAD7afzeDFlQ1Xm2X3g>.
Watsen, et al. Expires April 19, 2019 [Page 11]
Internet-Draft Handling Long Lines in Artwork October 2018
Appendix A. POSIX Shell Script
This non-normative appendix section includes a shell script that can
both fold and unfold artwork.
========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) ===========
#!/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
Watsen, et al. Expires April 19, 2019 [Page 12]
Internet-Draft Handling Long Lines in Artwork October 2018
cp $infile $outfile
return -1
fi
foldcol=`expr "$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 allow\
\ed."
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 follo\
\wed"
echo " by '\' as the first non-space character on the next\
\ line."
echo " This file cannot be 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 [ $? -eq 1 ]; then
mv /tmp/wip2 /tmp/wip
fold_it "recursing"
else
Watsen, et al. Expires April 19, 2019 [Page 13]
Internet-Draft Handling Long Lines in Artwork October 2018
echo "$header" > $outfile
echo "" >> $outfile
cat /tmp/wip2 >> $outfile
rm /tmp/wip*
fi
## following two lines represent a non-functional variant to the r\
\ecursive
## logic presented in the block above. It used to work before the\
\ '\'
## on the next line was added to the format (i.e., the trailing '\\
\\\\'
## in the substitution below), but now there is an off-by-one erro\
\r.
## Leaving here in case anyone can fix it.
#echo "$header" > $outfile
#echo "" >> $outfile
#gsed "/.\{$testcol\}/s/\(.\{$foldcol\}\)/\1\\\\\n\\\\/g" < $infil\
\e >> $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
}
Watsen, et al. Expires April 19, 2019 [Page 14]
Internet-Draft Handling Long Lines in Artwork October 2018
process_input() {
while [ "$1" != "" ]; do
if [ "$1" == "-h" -o "$1" == "--help" ]; then
print_usage
exit 1
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
Watsen, et al. Expires April 19, 2019 [Page 15]
Internet-Draft Handling Long Lines in Artwork October 2018
min_supported=`expr ${#hdr_txt} + 8`
if [ $maxcol -lt $min_supported ]; then
echo
echo "Error: the folding column cannot be less than $min_support\
\ed"
echo
exit 1
fi
max_supported=`expr ${#equal_chars} + 1 + ${#hdr_txt} + 1 + ${#equ\
\al_chars}`
if [ $maxcol -gt $max_supported ]; then
echo
echo "Error: the folding column cannot be more than $max_support\
\ed"
echo
exit 1
fi
}
main() {
if [ "$#" == "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): Jonathan Hansford, Joel Jaeggli, Lou Berger,
Martin Bjorklund, Italo Busi, and Rob Wilton.
Watsen, et al. Expires April 19, 2019 [Page 16]
Internet-Draft Handling Long Lines in Artwork October 2018
The authors additionally thank the RFC Editor, for confirming that
there is no set convention today for handling long lines in artwork.
Authors' Addresses
Kent Watsen
Juniper Networks
EMail: kwatsen@juniper.net
Qin Wu
Huawei Technologies
EMail: bill.wu@huawei.com
Adrian Farrel
Juniper Networks
EMail: afarrel@juniper.net
Benoit Claise
Cisco Systems, Inc.
EMail: bclaise@cisco.com
Watsen, et al. Expires April 19, 2019 [Page 17]