It’s surprisingly hard to get this right. I feel like I need this in order to use `ed` as the editor for `tin`, my current news client.
This is what I use:
alias tin='env EDITOR=ted tin -r'
Here’s “bin/ted”:
#! /bin/sh ed "$1" article-wrap < "$1" > "$1.fmt" mv "$1.fmt" "$1"
So first it calls ed and then it pipes the article through a filter.
This is the filter, “bin/article-wrap”:
#!/usr/bin/env perl
use Modern::Perl;
die "This filter wraps news posts.\n" if @ARGV;
binmode(STDIN, ':utf8');
binmode(STDOUT, ':utf8');
# headers
while (<STDIN>) {
chomp;
last if not $_; # end of headers
say; # header line
}
say; # empty line after headers
my $max = 72;
my $buffer;
my $prefix = '';
my $wrap = 1;
while (<STDIN>) {
chomp;
my ($new_prefix) = /([> ]*)/;
# empty lines don't get wrapped, nor lines with a space at the end, nor indented lines
my $empty = length() == 0 || /^$prefix\s*$/ || /\s$/ || /^\s/ || /^$prefix.{0,10}$/;
# ``` toggles wrap
$wrap = not $wrap if /^$prefix\s*```$/;
# end old paragraph with the old prefix if the prefix changed, an empty line,
# or not wrapping anymore
if ($buffer and ($new_prefix ne $prefix or $empty or not $wrap)) {
say $prefix . $buffer;
$buffer = '';
}
# print empty lines or not wrapped lines without stripping trailing whitespace
if ($empty or not $wrap) {
say $_;
next;
}
# continue old paragraph
$buffer .= " " if $buffer;
# strip the prefix
$prefix = $new_prefix;
$buffer .= substr($_, length($prefix));
# wrap what we have
while (length($buffer) > $max) {
# if there's a word that crosses the $max line size, break before
if (substr($buffer, 0, $max - length($prefix) + 1) =~ /(\s+(\w+))\w$/) {
say $prefix . substr($buffer, 0, $max - length($prefix) - length($1));
$buffer = substr($buffer, $max - length($prefix) - length($2));
} else {
my $line = substr($buffer, 0, $max - length($prefix));
$line =~ s/\s+$//;
say $prefix . $line;
$buffer = substr($buffer, $max - length($prefix));
$buffer =~ s/^\s+//;
}
}
}
say $prefix . $buffer if $buffer;
1;
Related “.tin/tinrc” settings:
#Programming #Mail #News
(Please contact me if you want to remove your comment.)
⁂
I’m wondering about implementing `aed` as a wrapper that calls `ed` and adds more commands... Or should I look at the `ed` source code‽
– Alex 2023-06-06 13:03 UTC
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I fear I’d have to track whether ed is in command-mode or edit mode…
This is based on the `perlipc(1)` man page.
use strict;
use warnings;
use IO::Socket;
use IPC::Open2;
my $file = shift;
local $SIG{PIPE} = sub { die "ed is done\n" };
my $pid = open2(my $out, my $in, 'ed', $file);
$in->autoflush(1);
$out->autoflush(1);
# split the program into two processes
die "can't fork: $!" unless defined(my $kidpid = fork());
if ($kidpid) {
# parent: copy ed output to standard output
while (<$out>) {
last unless defined;
print STDOUT $_;
}
kill("TERM", $kidpid); # send SIGTERM to child
} else {
# child: copy standard input to ed input
while (<STDIN>) {
print $in $_;
}
waitpid($pid, 0 );
exit($? >> 8);
}
– Alex 2023-06-06 21:29 UTC
---
Much blast from the past in June. Deliberately wrote a program in nano today.
– Blue Tyson 2023-07-28 11:33 UTC
---
Wow! How many lines? Code formatting by hand or using a tool?
– Alex 2023-07-28 11:38 UTC