Use https instead of http

29 files changed, 46 insertions, 46 deletions

diff --git a/array.c b/array.c
index a360041abf..ed1850356b 100644
--- a/array.c
+++ b/array.c
@@ -7226,7 +7226,7 @@ permute0(const long n, const long r, long *const p, char *const used, const VALU
 
 /*
  * Returns the product of from, from-1, ..., from - how_many + 1.
- * http://en.wikipedia.org/wiki/Pochhammer_symbol
+ * https://en.wikipedia.org/wiki/Pochhammer_symbol
  */
 static VALUE
 descending_factorial(long from, long how_many)
diff --git a/bignum.c b/bignum.c
index ed9c65e80d..65a50ea9ba 100644
--- a/bignum.c
+++ b/bignum.c
@@ -2006,7 +2006,7 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
     }
 
     /*
-     * ref. http://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication
+     * ref. https://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication
      *
      * x(b) = x0 * b^0 + x1 * b^1 + x2 * b^2
      * y(b) = y0 * b^0 + y1 * b^1 + y2 * b^2
diff --git a/enc/cp949.c b/enc/cp949.c
index bd2c8d21a4..1600d0cd5b 100644
--- a/enc/cp949.c
+++ b/enc/cp949.c
@@ -218,5 +218,5 @@ OnigEncodingDefine(cp949, CP949) = {
 /*
  * Name: CP949
  * Link: http://www.microsoft.com/globaldev/reference/dbcs/949.mspx
- * Link: http://en.wikipedia.org/wiki/EUC-KR#EUC-KR
+ * Link: https://en.wikipedia.org/wiki/EUC-KR#EUC-KR
  */
diff --git a/enc/euc_jp.c b/enc/euc_jp.c
index ded051af69..d283bf4ebb 100644
--- a/enc/euc_jp.c
+++ b/enc/euc_jp.c
@@ -593,7 +593,7 @@ ENC_ALIAS("eucJP", "EUC-JP") /* UI-OSF Application Platform Profile for Japanese
  * Name: eucJP-ms
  * Link: http://home.m05.itscom.net/numa/cde/ucs-conv/ucs-conv.html
  * Link: http://www2d.biglobe.ne.jp/~msyk/charcode/cp932/eucJP-ms.html
- * Link: http://ja.wikipedia.org/wiki/EUC-JP
+ * Link: https://ja.wikipedia.org/wiki/EUC-JP
  */
 ENC_REPLICATE("eucJP-ms", "EUC-JP") /* TOG/JVC CDE/Motif Technical WG */
 ENC_ALIAS("euc-jp-ms", "eucJP-ms")
@@ -610,7 +610,7 @@ ENC_REPLICATE("CP51932", "EUC-JP")
 
 /*
  * Name: EUC-JIS-2004
- * Link: http://ja.wikipedia.org/wiki/EUC-JIS-2004
+ * Link: https://ja.wikipedia.org/wiki/EUC-JIS-2004
  */
 ENC_REPLICATE("EUC-JIS-2004", "EUC-JP") /* defined at JIS X 0213:2004 */
 ENC_ALIAS("EUC-JISX0213", "EUC-JIS-2004") /* defined at JIS X 0213:2000, and obsolete at JIS X 0213:2004 */
diff --git a/enc/iso_8859_11.c b/enc/iso_8859_11.c
index 85e8f2cdb4..b9c6119fd9 100644
--- a/enc/iso_8859_11.c
+++ b/enc/iso_8859_11.c
@@ -102,7 +102,7 @@ ENC_ALIAS("ISO8859-11", "ISO-8859-11")
 /*
  * Name: TIS-620
  * MIBenum: 2259
- * Link: http://en.wikipedia.org/wiki/Thai_Industrial_Standard_620-2533
+ * Link: https://en.wikipedia.org/wiki/Thai_Industrial_Standard_620-2533
  */
 ENC_REPLICATE("TIS-620", "ISO-8859-11")
 
diff --git a/enc/iso_8859_6.c b/enc/iso_8859_6.c
index 6d852ac8c0..cdb74054d1 100644
--- a/enc/iso_8859_6.c
+++ b/enc/iso_8859_6.c
@@ -104,7 +104,7 @@ ENC_ALIAS("ISO8859-6", "ISO-8859-6")
  * MIBenum: 2256
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1256.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1256
+ * Link: https://en.wikipedia.org/wiki/Windows-1256
  */
 ENC_REPLICATE("Windows-1256", "ISO-8859-6")
 ENC_ALIAS("CP1256", "Windows-1256")
diff --git a/enc/iso_8859_8.c b/enc/iso_8859_8.c
index 0a7a29e82e..e256855f21 100644
--- a/enc/iso_8859_8.c
+++ b/enc/iso_8859_8.c
@@ -104,7 +104,7 @@ ENC_ALIAS("ISO8859-8", "ISO-8859-8")
  * MIBenum: 2255
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1255.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1255
+ * Link: https://en.wikipedia.org/wiki/Windows-1255
  */
 ENC_REPLICATE("Windows-1255", "ISO-8859-8")
 ENC_ALIAS("CP1255", "Windows-1255")
diff --git a/enc/shift_jis.c b/enc/shift_jis.c
index 65fd5102de..f1355d2d95 100644
--- a/enc/shift_jis.c
+++ b/enc/shift_jis.c
@@ -55,13 +55,13 @@ OnigEncodingDefine(shift_jis, Shift_JIS) = {
  * Name: Shift_JIS
  * MIBenum: 17
  * Link: http://www.iana.org/assignments/character-sets
- * Link: http://ja.wikipedia.org/wiki/Shift_JIS
+ * Link: https://ja.wikipedia.org/wiki/Shift_JIS
  */
 
 /*
  * Name: MacJapanese
  * Link: http://unicode.org/Public/MAPPINGS/VENDORS/APPLE/JAPANESE.TXT
- * Link: http://ja.wikipedia.org/wiki/MacJapanese
+ * Link: https://ja.wikipedia.org/wiki/MacJapanese
  */
 ENC_REPLICATE("MacJapanese", "Shift_JIS")
 ENC_ALIAS("MacJapan", "MacJapanese")
diff --git a/enc/windows_1250.c b/enc/windows_1250.c
index d2cf7b16bc..daf23e9d1e 100644
--- a/enc/windows_1250.c
+++ b/enc/windows_1250.c
@@ -266,6 +266,6 @@ OnigEncodingDefine(windows_1250, Windows_1250) = {
  * MIBenum: 2251
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1250.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1250
+ * Link: https://en.wikipedia.org/wiki/Windows-1250
  */
 ENC_ALIAS("CP1250", "Windows-1250")
diff --git a/enc/windows_1251.c b/enc/windows_1251.c
index fcd0f1015d..6c892c1b8c 100644
--- a/enc/windows_1251.c
+++ b/enc/windows_1251.c
@@ -248,6 +248,6 @@ OnigEncodingDefine(windows_1251, Windows_1251) = {
  * MIBenum: 2251
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1251.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1251
+ * Link: https://en.wikipedia.org/wiki/Windows-1251
  */
 ENC_ALIAS("CP1251", "Windows-1251")
diff --git a/enc/windows_1252.c b/enc/windows_1252.c
index 5f90c15601..b685878d3f 100644
--- a/enc/windows_1252.c
+++ b/enc/windows_1252.c
@@ -255,6 +255,6 @@ OnigEncodingDefine(windows_1252, Windows_1252) = {
  * MIBenum: 2251
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1252.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1252
+ * Link: https://en.wikipedia.org/wiki/Windows-1252
  */
 ENC_ALIAS("CP1252", "Windows-1252")
diff --git a/enc/windows_1253.c b/enc/windows_1253.c
index 9e9c63a581..b2a43581c3 100644
--- a/enc/windows_1253.c
+++ b/enc/windows_1253.c
@@ -32,7 +32,7 @@
  * MIBenum: 2253
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1253.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1253
+ * Link: https://en.wikipedia.org/wiki/Windows-1253
  */
 
 #include "regenc.h"
diff --git a/enc/windows_1254.c b/enc/windows_1254.c
index 9ae66978a2..5e6d92d3d2 100644
--- a/enc/windows_1254.c
+++ b/enc/windows_1254.c
@@ -32,7 +32,7 @@
  * MIBenum: 2254
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1254.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1254
+ * Link: https://en.wikipedia.org/wiki/Windows-1254
  */
 
 #include "regenc.h"
diff --git a/enc/windows_1257.c b/enc/windows_1257.c
index 936a94ac76..ada03b72bf 100644
--- a/enc/windows_1257.c
+++ b/enc/windows_1257.c
@@ -35,7 +35,7 @@
  * MIBenum: 2257
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/sbcs/1257.mspx
- * Link: http://en.wikipedia.org/wiki/Windows-1257
+ * Link: https://en.wikipedia.org/wiki/Windows-1257
  */
 
 #define ENC_CP1252_TO_LOWER_CASE(c) EncCP1252_ToLowerCaseTable[c]
diff --git a/enc/windows_31j.c b/enc/windows_31j.c
index e3a468f414..1eb859596a 100644
--- a/enc/windows_31j.c
+++ b/enc/windows_31j.c
@@ -57,7 +57,7 @@ OnigEncodingDefine(windows_31j, Windows_31J) = {
  * MIBenum: 2024
  * Link: http://www.iana.org/assignments/character-sets
  * Link: http://www.microsoft.com/globaldev/reference/dbcs/932.mspx
- * Link: http://ja.wikipedia.org/wiki/Windows-31J
+ * Link: https://ja.wikipedia.org/wiki/Windows-31J
  * Link: http://source.icu-project.org/repos/icu/data/trunk/charset/data/ucm/windows-932-2000.ucm
  *
  * Windows Standard Character Set and its mapping to Unicode by Microsoft.
diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 451ce7e7f3..f9567e23e8 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -9589,18 +9589,18 @@ Init_date_core(void)
      * === When should you use DateTime and when should you use Time?
      *
      * It's a common misconception that
-     * {William Shakespeare}[http://en.wikipedia.org/wiki/William_Shakespeare]
+     * {William Shakespeare}[https://en.wikipedia.org/wiki/William_Shakespeare]
      * and
-     * {Miguel de Cervantes}[http://en.wikipedia.org/wiki/Miguel_de_Cervantes]
+     * {Miguel de Cervantes}[https://en.wikipedia.org/wiki/Miguel_de_Cervantes]
      * died on the same day in history -
      * so much so that UNESCO named April 23 as
-     * {World Book Day because of this fact}[http://en.wikipedia.org/wiki/World_Book_Day].
+     * {World Book Day because of this fact}[https://en.wikipedia.org/wiki/World_Book_Day].
      * However, because England hadn't yet adopted the
-     * {Gregorian Calendar Reform}[http://en.wikipedia.org/wiki/Gregorian_calendar#Gregorian_reform]
-     * (and wouldn't until {1752}[http://en.wikipedia.org/wiki/Calendar_(New_Style)_Act_1750])
+     * {Gregorian Calendar Reform}[https://en.wikipedia.org/wiki/Gregorian_calendar#Gregorian_reform]
+     * (and wouldn't until {1752}[https://en.wikipedia.org/wiki/Calendar_(New_Style)_Act_1750])
      * their deaths are actually 10 days apart.
      * Since Ruby's Time class implements a
-     * {proleptic Gregorian calendar}[http://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar]
+     * {proleptic Gregorian calendar}[https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar]
      * and has no concept of calendar reform there's no way
      * to express this with Time objects. This is where DateTime steps in:
      *
@@ -9644,7 +9644,7 @@ Init_date_core(void)
      *      #=> Fri, 04 May 1753 00:00:00 +0000
      *
      * As you can see, if we're accurately tracking the number of
-     * {solar years}[http://en.wikipedia.org/wiki/Tropical_year]
+     * {solar years}[https://en.wikipedia.org/wiki/Tropical_year]
      * since Shakespeare's birthday then the correct anniversary date
      * would be the 4th May and not the 23rd April.
      *
@@ -9656,10 +9656,10 @@ Init_date_core(void)
      * making the same mistakes as UNESCO. If you also have to deal
      * with timezones then best of luck - just bear in mind that
      * you'll probably be dealing with
-     * {local solar times}[http://en.wikipedia.org/wiki/Solar_time],
+     * {local solar times}[https://en.wikipedia.org/wiki/Solar_time],
      * since it wasn't until the 19th century that the introduction
      * of the railways necessitated the need for
-     * {Standard Time}[http://en.wikipedia.org/wiki/Standard_time#Great_Britain]
+     * {Standard Time}[https://en.wikipedia.org/wiki/Standard_time#Great_Britain]
      * and eventually timezones.
      */
 
diff --git a/ext/dbm/dbm.c b/ext/dbm/dbm.c
index bc1d527735..de7536651c 100644
--- a/ext/dbm/dbm.c
+++ b/ext/dbm/dbm.c
@@ -980,7 +980,7 @@ fdbm_reject(VALUE obj)
  * == Introduction
  *
  * The DBM class provides a wrapper to a Unix-style
- * {dbm}[http://en.wikipedia.org/wiki/Dbm] or Database Manager library.
+ * {dbm}[https://en.wikipedia.org/wiki/Dbm] or Database Manager library.
  *
  * Dbm databases do not have tables or columns; they are simple key-value
  * data stores, like a Ruby Hash except not resident in RAM. Keys and values
@@ -992,7 +992,7 @@ fdbm_reject(VALUE obj)
  * - The original ndbm library is released in 4.3BSD.
  *   It is based on dbm library in Unix Version 7 but has different API to
  *   support multiple databases in a process.
- * - {Berkeley DB}[http://en.wikipedia.org/wiki/Berkeley_DB] versions
+ * - {Berkeley DB}[https://en.wikipedia.org/wiki/Berkeley_DB] versions
  *   1 thru 6, also known as BDB and Sleepycat DB, now owned by Oracle
  *   Corporation.
  * - Berkeley DB 1.x, still found in 4.4BSD derivatives (FreeBSD, OpenBSD, etc).
diff --git a/ext/monitor/lib/monitor.rb b/ext/monitor/lib/monitor.rb
index 08a3a31ef0..11c5ac17d9 100644
--- a/ext/monitor/lib/monitor.rb
+++ b/ext/monitor/lib/monitor.rb
@@ -17,7 +17,7 @@
 # structure.
 #
 # You can read more about the general principles on the Wikipedia page for
-# Monitors[http://en.wikipedia.org/wiki/Monitor_%28synchronization%29]
+# Monitors[https://en.wikipedia.org/wiki/Monitor_%28synchronization%29]
 #
 # == Examples
 #
diff --git a/ext/pty/pty.c b/ext/pty/pty.c
index 485f61c304..a51393026c 100644
--- a/ext/pty/pty.c
+++ b/ext/pty/pty.c
@@ -694,7 +694,7 @@ static VALUE cPTY;
  * Document-class: PTY
  *
  * Creates and manages pseudo terminals (PTYs).  See also
- * http://en.wikipedia.org/wiki/Pseudo_terminal
+ * https://en.wikipedia.org/wiki/Pseudo_terminal
  *
  * PTY allows you to allocate new terminals using ::open or ::spawn a new
  * terminal with a specific command.
diff --git a/numeric.c b/numeric.c
index b40984e4ec..468defe78e 100644
--- a/numeric.c
+++ b/numeric.c
@@ -913,7 +913,7 @@ num_negative_p(VALUE num)
  *
  *  - http://docs.sun.com/source/806-3568/ncg_goldberg.html
  *  - https://github.com/rdp/ruby_tutorials_core/wiki/Ruby-Talk-FAQ#floats_imprecise
- *  - http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems
+ *  - https://en.wikipedia.org/wiki/Floating_point#Accuracy_problems
  */
 
 VALUE
diff --git a/sample/trick2013/mame/remarks.markdown b/sample/trick2013/mame/remarks.markdown
index 8c1988c809..488681d88d 100644
--- a/sample/trick2013/mame/remarks.markdown
+++ b/sample/trick2013/mame/remarks.markdown
@@ -27,7 +27,7 @@ In the piano roll, `#` represents a pin that hits a note, and `|` represents a s
 The leftmost column corresponds 110Hz (low A).
 Every column corresponds a semitone higher than the left one.
 
-This program uses [the frequency modulation synthesis](http://en.wikipedia.org/wiki/Frequency_modulation_synthesis) to play the sound like a music-box.
+This program uses [the frequency modulation synthesis](https://en.wikipedia.org/wiki/Frequency_modulation_synthesis) to play the sound like a music-box.
 You can create a different-sounding tone by changing the parameter.
 For example, the following will play the sound like a harpsichord.
 
@@ -44,4 +44,4 @@ You have to use sox by replacing the following part:
 
 with:
 
-    IO.popen("./pl","wb")
\ No newline at end of file
+    IO.popen("./pl","wb")
diff --git a/spec/ruby/library/cgi/escape_spec.rb b/spec/ruby/library/cgi/escape_spec.rb
index 2f1913970e..c599a73cf0 100644
--- a/spec/ruby/library/cgi/escape_spec.rb
+++ b/spec/ruby/library/cgi/escape_spec.rb
@@ -7,8 +7,8 @@ describe "CGI.escape" do
     expected = "+%21%22%23%24%25%26%27%28%29%2A%2B%2C-.%2F0123456789%3A%3B%3C%3D%3E%3F%40ABCDEFGHIJKLMNOPQRSTUVWXYZ%5B%5C%5D%5E_%60abcdefghijklmnopqrstuvwxyz%7B%7C%7D"
     CGI.escape(input).should == expected
 
-    input = "http://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
-    expected = 'http%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
+    input = "https://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
+    expected = 'https%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
     CGI.escape(input).should == expected
   end
 
diff --git a/spec/ruby/library/cgi/unescape_spec.rb b/spec/ruby/library/cgi/unescape_spec.rb
index db4834e7e8..c593e24b4a 100644
--- a/spec/ruby/library/cgi/unescape_spec.rb
+++ b/spec/ruby/library/cgi/unescape_spec.rb
@@ -8,8 +8,8 @@ describe "CGI.unescape" do
     expected = " !\"\#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~"
     CGI.unescape(input).should == expected
 
-    input    = 'http%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
-    expected = "http://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
+    input    = 'https%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
+    expected = "https://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
     CGI.unescape(input).should == expected
   end
 end
diff --git a/spec/ruby/library/erb/util/shared/url_encode.rb b/spec/ruby/library/erb/util/shared/url_encode.rb
index a2d648fd31..34009c4903 100644
--- a/spec/ruby/library/erb/util/shared/url_encode.rb
+++ b/spec/ruby/library/erb/util/shared/url_encode.rb
@@ -11,8 +11,8 @@ describe :erb_util_url_encode, shared: true do
   end
 
   it "encode unicode string" do
-    input = "http://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
-    expected = 'http%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
+    input = "https://ja.wikipedia.org/wiki/\343\203\255\343\203\240\343\202\271\343\202\253\343\203\273\343\203\221\343\203\255\343\203\273\343\202\246\343\203\253\343\203\273\343\203\251\343\203\224\343\203\245\343\202\277"
+    expected = 'https%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%E3%83%AD%E3%83%A0%E3%82%B9%E3%82%AB%E3%83%BB%E3%83%91%E3%83%AD%E3%83%BB%E3%82%A6%E3%83%AB%E3%83%BB%E3%83%A9%E3%83%94%E3%83%A5%E3%82%BF'
     ERB::Util.__send__(@method, input).should == expected
   end
 
diff --git a/string.c b/string.c
index 8bcc6bb9c8..2759aaa94a 100644
--- a/string.c
+++ b/string.c
@@ -1729,7 +1729,7 @@ rb_str_init(int argc, VALUE *argv, VALUE str)
 
 /*
  * UTF-8 leading bytes have either 0xxxxxxx or 11xxxxxx
- * bit representation. (see http://en.wikipedia.org/wiki/UTF-8)
+ * bit representation. (see https://en.wikipedia.org/wiki/UTF-8)
  * Therefore, the following pseudocode can detect UTF-8 leading bytes.
  *
  * if (!(byte & 0x80))
diff --git a/test/rdoc/test_rdoc_markup_to_markdown.rb b/test/rdoc/test_rdoc_markup_to_markdown.rb
index 4d3a005381..c8c5fd4d52 100644
--- a/test/rdoc/test_rdoc_markup_to_markdown.rb
+++ b/test/rdoc/test_rdoc_markup_to_markdown.rb
@@ -363,9 +363,9 @@ words words words words
 
   def test_convert_TIDYLINK
     result = @to.convert \
-      '{DSL}[http://en.wikipedia.org/wiki/Domain-specific_language]'
+      '{DSL}[https://en.wikipedia.org/wiki/Domain-specific_language]'
 
-    expected = "[DSL](http://en.wikipedia.org/wiki/Domain-specific_language)\n"
+    expected = "[DSL](https://en.wikipedia.org/wiki/Domain-specific_language)\n"
 
     assert_equal expected, result
   end
diff --git a/time.c b/time.c
index 70725b7fe0..51b7a262ac 100644
--- a/time.c
+++ b/time.c
@@ -4456,7 +4456,7 @@ time_ceil(int argc, VALUE *argv, VALUE time)
  *  Returns the second of the minute (0..60) for _time_.
  *
  *  *Note:* Seconds range from zero to 60 to allow the system to inject
- *  leap seconds. See http://en.wikipedia.org/wiki/Leap_second for further
+ *  leap seconds. See https://en.wikipedia.org/wiki/Leap_second for further
  *  details.
  *
  *     t = Time.now   #=> 2007-11-19 08:25:02 -0600
@@ -5776,7 +5776,7 @@ rb_time_zone_abbreviation(VALUE zone, VALUE time)
  *
  *  You can also create a new time using Time.at which takes the number of
  *  seconds (with subsecond) since the {Unix
- *  Epoch}[http://en.wikipedia.org/wiki/Unix_time].
+ *  Epoch}[https://en.wikipedia.org/wiki/Unix_time].
  *
  *    Time.at(628232400) #=> 1989-11-28 00:00:00 -0500
  *
diff --git a/tool/lib/minitest/benchmark.rb b/tool/lib/minitest/benchmark.rb
index b3f2bc28b3..547b516c4b 100644
--- a/tool/lib/minitest/benchmark.rb
+++ b/tool/lib/minitest/benchmark.rb
@@ -219,7 +219,7 @@ class MiniTest::Unit # :nodoc:
     ##
     # Takes an array of x/y pairs and calculates the general R^2 value.
     #
-    # See: http://en.wikipedia.org/wiki/Coefficient_of_determination
+    # See: https://en.wikipedia.org/wiki/Coefficient_of_determination
 
     def fit_error xys
       y_bar  = sigma(xys) { |x, y| y } / xys.size.to_f
diff --git a/win32/file.c b/win32/file.c
index 133b5fbdb0..71320242e2 100644
--- a/win32/file.c
+++ b/win32/file.c
@@ -157,7 +157,7 @@ replace_to_long_name(wchar_t **wfullpath, size_t size, size_t buffer_size)
     /*
       Skip long name conversion if the path is already long name.
       Short name is 8.3 format.
-      http://en.wikipedia.org/wiki/8.3_filename
+      https://en.wikipedia.org/wiki/8.3_filename
       This check can be skipped for directory components that have file
       extensions longer than 3 characters, or total lengths longer than
       12 characters.