grep-changelogコマンドが、どのようにテキスト整形しているか気になるところです。
おそらくスクリプトなので、シンボリックリンクを辿っていきます。
takk@deb9:~$ which grep-changelog /usr/bin/grep-changelog takk@deb9:~$
takk@deb9:~$ !! | xargs file which grep-changelog | xargs file /usr/bin/grep-changelog: symbolic link to /etc/alternatives/grep-changelog takk@deb9:~$
takk@deb9:~$ ^file^readlink -e^ which grep-changelog | xargs readlink -e /usr/bin/grep-changelog.emacs24 takk@deb9:~$
takk@deb9:~$ !! | xargs file which grep-changelog | xargs readlink -e | xargs file /usr/bin/grep-changelog.emacs24: Perl script text executable takk@deb9:~$
なんとPerlでしたね。
takk@deb9:~$ ^file^wc -l^ which grep-changelog | xargs readlink -e | xargs wc -l 265 /usr/bin/grep-changelog.emacs24 takk@deb9:~$
265行。
行数も少ないので全文みてみます。
takk@deb9:~$ ^wc -l^cat -n^
which grep-changelog | xargs readlink -e | xargs cat -n
1 #! /usr/bin/perl
2
3 # Copyright (C) 1999-2015 Free Software Foundation, Inc.
4 #
5 # This file is part of GNU Emacs.
6
7 # GNU Emacs is free software: you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation, either version 3 of the License, or
10 # (at your option) any later version.
11
12 # GNU Emacs is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
16
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
19
20
21 # Extract entries from ChangeLogs matching specified criteria.
22 # Optionally format the resulting output to a form suitable for RCS
23 # logs, like they are used in Emacs, for example. In this format,
24 # author lines, leading spaces, and file names are removed.
25
26 require 5;
27 use strict;
28
29 # Parse command line options.
30
31 use vars qw($author $regexp $exclude $from_date $to_date
32 $rcs_log $with_date $version $help $reverse
33 @entries);
34
35 use Getopt::Long;
36
37 my $result;
38
39 if (@ARGV == 0) {
40
41 # No arguments cannot possibly mean "show everything"!!
42 $result = 0;
43
44 } else {
45
46 $result = GetOptions ("author=s" => \$author,
47 "text=s" => \$regexp,
48 "exclude=s" => \$exclude,
49 "from-date=s" => \$from_date,
50 "to-date=s" => \$to_date,
51 "rcs-log" => \$rcs_log,
52 "with-date" => \$with_date,
53 "reverse!" => \$reverse,
54 "version" => \$version,
55 "help" => \$help);
56
57 # If date options are specified, check that they have the format
58 # YYYY-MM-DD.
59
60 $result = 0 if $from_date && $from_date !~ /^\d\d\d\d-\d\d-\d\d$/;
61 $result = 0 if $to_date && $to_date !~ /^\d\d\d\d-\d\d-\d\d$/;
62 }
63
64 # Print usage information and exit when necessary.
65
66 if ($result == 0 || $help) {
67 print <<USAGE;
68
69 Usage: $0 [options] [CHANGELOG...]
70
71 Print entries in ChangeLogs matching various criteria.
72 Valid options are:
73
74 --author=AUTHOR Match entries whose author line matches
75 regular expression AUTHOR
76 --text=TEXT Match entries whose text matches regular
77 expression TEXT
78 --exclude=TEXT Exclude entries matching TEXT
79 --from-date=YYYY-MM-DD Match entries not older than given date
80 --to-date=YYYY-MM-DD Match entries not younger than given date
81 --rcs-log Format output suitable for RCS log entries
82 --with-date Print short date line in RCS log
83 --reverse Show entries in reverse (chronological) order
84 --version Print version info
85 --help Print this help
86
87 If no CHANGELOG is specified scan the files "ChangeLog" and
88 "ChangeLog.N+" in the current directory. Old-style dates in ChangeLogs
89 are not recognized.
90 USAGE
91 exit !$help;
92 }
93
94 # Print version info and exit if `--version' was specified.
95
96 if ($version) {
97 print "0.3\n";
98 exit 0;
99 }
100
101
102 # Value is non-zero if HEADER matches according to command line
103 # options specified, i.e. it matches $author, and its date is in
104 # the range $from_date <= date <= $to_date.
105
106 sub header_match_p {
107 my $header = shift;
108
109 return 0 unless $header;
110
111 # No match if AUTHOR-regexp specified and doesn't match.
112 return 0 if $author && $header !~ /$author/;
113
114 # Check that the date of the entry matches if date options
115 # `--from-date' and/or `--to-date' were specified . Old-style
116 # dates in ChangeLogs are not recognized, and never match.
117 if ($from_date || $to_date) {
118 if ($header =~ /^(\d\d\d\d-\d\d-\d\d)/) {
119 my $date = $1;
120 return 0 if $from_date && $date lt $from_date;
121 return 0 if $to_date && $date gt $to_date;
122 } else {
123 # Don't bother recognizing old-style dates.
124 return 0;
125 }
126 }
127
128 return 1;
129 }
130
131
132 # Value is non-zero if ENTRY matches the criteria specified on the
133 # command line, i.e. it matches $regexp, and it doesn't match
134 # $exclude.
135
136 sub entry_match_p {
137 my $entry = shift;
138
139 return 0 unless $entry;
140
141 if ($regexp) {
142 return 1 if ($entry =~ /$regexp/
143 && (!$exclude || $entry !~ $exclude));
144 } else {
145 return 1 if !$exclude || $entry !~ $exclude;
146 }
147
148 return 0;
149 }
150
151
152 # Print HEADER and/or ENTRY in a format suitable for what was
153 # specified on the command line. If $rcs_log is specified, author
154 # lines are not printed, and leading spaces and file names are removed
155 # from ChangeLog entries.
156
157 sub print_log {
158 my ($header, $entry) = @_;
159 my $output = '';
160
161 if ($rcs_log) {
162 # Remove leading whitespace from entry.
163 $entry =~ s/^\s+//mg;
164 # Remove file name parts.
165 $entry =~ s/^\*.*\(/(/mg;
166 # Remove file name parts, 2.
167 $entry =~ s/^\*.*://mg;
168 if ($with_date) {
169 $header =~ /(\d\d\d\d-\d\d-\d\d)/;
170 $output = "!changelog-date $1\n";
171 }
172 $output .= $entry;
173 } else {
174 $output .= $header . $entry;
175 }
176
177 if ($reverse) {
178 push @entries, $output;
179 } else {
180 print $output;
181 }
182 }
183
184 # Scan LOG for matching entries, and print them to standard output.
185
186 sub parse_changelog {
187 my $log = shift;
188 my $entry = undef;
189 my $header = undef;
190
191 @entries = () if $reverse;
192
193 # Open the ChangeLog.
194 open (IN, "< $log") || die "Cannot open $log: $!";
195
196 while (defined(my $line = <IN>)) {
197 if ($line =~ /^\S/) {
198 # Line is an author-line. Print previous entry if
199 # it matches.
200 print_log ($header, $entry)
201 if header_match_p ($header) && entry_match_p ($entry);
202
203 $entry = "";
204 $header = $line;
205
206 # Add empty lines below the header.
207 while (defined($line = <IN>) && $line =~ /^\s*$/) {
208 $header = "$header$line";
209 }
210 }
211
212 last unless defined $line;
213
214 if ($line =~ /^\s*\*/) {
215 # LINE is the first line of a ChangeLog entry. Print
216 # previous entry if it matches.
217 print_log ($header, $entry)
218 if header_match_p ($header) && entry_match_p ($entry);
219 $entry = $line;
220 } else {
221 # Add LINE to the current entry.
222 $entry = "$entry$line";
223 }
224 }
225
226 # Print last entry if it matches.
227 print_log ($header, $entry)
228 if header_match_p ($header) && entry_match_p ($entry);
229
230 close IN;
231
232 if ($reverse) {
233 for (my $entry = @entries; $entry; $entry--) {
234 print $entries[$entry-1];
235 }
236 }
237 }
238
239
240 # Main program. Process ChangeLogs.
241
242 # If files were specified on the command line, parse those files in the
243 # order supplied by the user; otherwise parse default files ChangeLog and
244 # ChangeLog.NNN according to $reverse.
245 unless (@ARGV > 0) {
246 @ARGV = ("ChangeLog");
247
248 push @ARGV,
249 map {"ChangeLog.$_"}
250 sort {$b <=> $a}
251 map {/\.(\d+)$/; $1}
252 do {
253 opendir D, '.';
254 grep /^ChangeLog\.\d+$/, readdir D;
255 };
256
257 @ARGV = reverse @ARGV if $reverse;
258 }
259
260 while (defined (my $log = shift @ARGV)) {
261 parse_changelog ($log) if -f $log;
262 }
263
264
265 # grep-changelog ends here.
takk@deb9:~$
メイン処理は、240行目からなので、ここから見ていこうと思いましたが、
いきなり分かりません。
246 @ARGV = ("ChangeLog");
これって配列初期化しているだけなのでしょうけど、なぜChangeLogって文字列で初期化しているんでしょう。
ふむふむ、面白くなってきました。
つづく
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