improve how markdown code language is commented

We added a space between the markdown triple code mark
and language that was enclosed in HTML comments.

So a line of the form:

````
```<!---c--->
````

became:

````
``` <!---c--->
````

This was done to **help** some code see that the HTML comment
string was not a markdown code specifier.   Not all code
understands this after this changed.  For example, `pandoc(1)`
still forms HTML classes of the form "&lt;!---c--&gt;"
when it encounters the above mentioned change.

We also fixed a problem with `2019/dogon/README.md` regarding
a markdown code block.

We also fixed a problem with `2020/yang/README.md` regarding
a markdown code block.

2018/algmyr/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -22,7 +22,7 @@ For more detailed information see [2018 algmyr bugs](../../bugs.html#2018_algmyr
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < prog.c			# Print garbage: might mess up your terminal
     ./prog <file1> <file2> > out.raw
     ./prog -d 2 0 out.raw		# Decode the first (0th) channel out of two
@@ -31,7 +31,7 @@ For more detailed information see [2018 algmyr bugs](../../bugs.html#2018_algmyr
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -164,13 +164,13 @@ standards compliant). This is used to print the usage instructions.
 
 Compiling using
 
-```<!---sh-->
+``` <!---sh-->
     gcc -Wall -Wextra -pedantic
 ```
 
 gives only `-Wmisleading-indentation` which is sensible considering the source code. While
 
-```<!---sh-->
+``` <!---sh-->
     clang -Wall -Wextra -pedantic
 ```
 
@@ -179,7 +179,7 @@ bodies), `-Wstring-plus-int` (since apparently some people think string+`int` is
 concatenation) and one of the weirder warnings I have seen from me splitting a
 negative constant with whitespace. Compiling using
 
-```<!---sh-->
+``` <!---sh-->
     clang -Wall -Wextra -pedantic -Weverything
 ```
 

2018/anderson/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -10,14 +10,14 @@ code](#alternate-code) below for more details.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < textfile
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -31,7 +31,7 @@ it was not the shape of the Roman V that we, or the compiler, didn't like.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -43,7 +43,7 @@ Use `prog.alt` as you would `prog` above.
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -58,7 +58,7 @@ down](http://en.wikipedia.org/wiki/River_%28typography%29)!
 
 ### Compiling the program:
 
-```<!---sh-->
+``` <!---sh-->
     cc -Wall -Wextra -Wpedantic -O3 -std=c11 prog.c -o prog
 ```
 

2018/bellard/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -10,7 +10,7 @@ code](#alternate-code) below.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog > lena.ppm
 ```
 
@@ -21,7 +21,7 @@ First open [Lenna.png](Lenna.png) in your graphics viewer of choice. Next, after
 running the above command (`./prog > lena.ppm`), open `lena.ppm` in your
 graphics viewer of choice.  After that try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -44,7 +44,7 @@ for Windows.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -99,7 +99,7 @@ Although the program was optimized to decompress its built-in image,
 it accepts to decompress image files from its standard
 input. Examples:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog d < lena512.bin > lena512.ppm
     ./prog d < fruits.bin > fruits.ppm
     ./prog d < vintage_cars.bin > vintage_cars.ppm

2018/burton1/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -10,14 +10,14 @@ code](#alternate-code) below.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < any-file
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -32,7 +32,7 @@ with `-Wno-` options.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -82,7 +82,7 @@ and without bypassing the solution using `execve(2)`, or functions built upon it
 E.g:
 
 
-```<!---c-->
+``` <!---c-->
     main(){system("hd");}	// it's turtles all the way down!
 ```
 
@@ -96,7 +96,7 @@ This solution is pleasing, but a true one-liner was the hoped-for goal.
 Here is the 157 character version in it's entirety:
 
 
-```<!---c-->
+``` <!---c-->
     char     O,o[  20];L(O){
     putchar  ( O+  48+39  *(9<
     O));}    I(O)  {L(~     15);
@@ -115,7 +115,7 @@ The progression to the present size is interesting,
 and it is interesting that the same algorithm can be expressed so differently
 by slight rearrangement of its parts.
 
-```<!---c-->
+``` <!---c-->
     // 119
     char O,o[20];main(l){for(;~(l=getchar());O||puts(o))o[O++]=isprint(l)?l:46,O&=15,printf("%02x ",l);O[o]=0;O&&puts(o);}
     // 116
@@ -139,7 +139,7 @@ These do not compete in the same category, since their output is materially diff
 They are derived from the solutions above, but are still fascinating as concise utilities,
 so here is their progression, for the curious:
 
-```<!---c-->
+``` <!---c-->
     // 102
     I;O(O){putchar(O+48+39*(9<O));}main(l){for(;~(l=getchar());O(++I&15?~15:~37))O(l>>4),O(l&15);O(-38);}
     // 80
@@ -156,7 +156,7 @@ It is possible to reduce the size of each of these by one by eliding the trailin
 This was not reported above since the newline kept getting appended by processing software,
 and it is more interesting to remove characters by changing code than by filtering:
 
-```<!---sh-->
+``` <!---sh-->
     $ tr -d '\012' < 109.c | wc -c
     108
     $ tr -d '\012' < 76.c | wc -c
@@ -257,13 +257,13 @@ the expression within the ternary remains too complex.
 
 Try:
 
-```<!---sh-->
+``` <!---sh-->
     cat prog.c prog.alt.c
 ```
 
 or
 
-```<!---sh-->
+``` <!---sh-->
     cmp -b prog.c prog.alt.c
 ```
 

2018/burton2/README.md

@@ -1,26 +1,26 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog [-tcksri] < file.c
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
 If you get really stuck, try:
 
-```<!---sh-->
+``` <!---sh-->
     man ./tac.1
 ```
 
@@ -113,7 +113,7 @@ There is one (known) remaining problem with detection:
 * Comments between preprocessor hash and keyword are not replaced with whitespace;
 the following counts #include as two tokens, `#` and `include` (not as a reserved word):
 
-```<!---c-->
+``` <!---c-->
     #/*this will not be counted*/include/*correctly*/<stdio.h>
 ```
 
@@ -128,14 +128,14 @@ counting words correctly absent `-k`.
 
 `tac` was run over all 366 previous IOCCC winning entries:
 
-```<!---sh-->
+``` <!---sh-->
     find ~/src/obc -type f -name \*.c | wc
 ```
 
 The discrepancies found are documented and explained in the file
 [discrepancies.html](discrepancies.html).
 
-```<!---sh-->
+``` <!---sh-->
     find ~/src/obc -type f -a -name "*.c" | xargs ./spotcheck.sh ./prog | ./spotdiff.sh |
 	    grep -v keep | diff -bw - discrep* | grep "[<>] cl "
 ```
@@ -181,14 +181,14 @@ For instance, here is a simple token counter, useful in finding repeated long to
 frequency, or counting the references to identifiers, constants, or breadth of use of the
 language:
 
-```<!---sh-->
+``` <!---sh-->
     #!/usr/bin/env bash
     cat $* | ./prog -t | sort | uniq -c | sort -k1nr
 ```
 
 And here is a C keyword frequency counter:
 
-```<!---sh-->
+``` <!---sh-->
     #!/usr/bin/env bash
     function iskeyword {
        awk 'BEGIN{f="c11";while(getline<f)k[$1]=0} {if($1 in k)k[$1]++}END{for(i in k)print k[i],i}'
@@ -222,7 +222,7 @@ simple code below is a serviceable obfuscated C de-obfuscator in a _scripting
 language_.  It really is this easy with `tac`:
 
 
-```<!---sh-->
+``` <!---sh-->
     #!/usr/bin/env bash
     script='
     BEGIN {
@@ -342,7 +342,7 @@ which is neither complete (`#define`, `#ifndef`, `#undef` are missing
 -- yes, Virginia knows about `#define` omitted on purpose),
 nor correct (many more are added: `I`, `true`, `bool`, `compl`, ...):
 
-```<!---sh-->
+``` <!---sh-->
     (sed -n '1p' c11; sed -n '2,$p' ioccc.kw.freq | sort) | comm -3 - c11
 ```
 
@@ -383,7 +383,7 @@ NB: This is *not* a portability concern, the one string holds only printable ASC
 
 Thus:
 
-```<!---sh-->
+``` <!---sh-->
     cc -ansi -Wall -trigraphs -Wno-trigraphs -Wno-parentheses -Wno-empty-body -Wno-char-subscripts -Wno-pointer-sign -DU=O -DW=\"keywords\" -o prog prog.c
 ```
 
@@ -403,7 +403,7 @@ are not recognised when written as `-rs` in prose).
 
 Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./manpage.sh tac
 
     ./manpage.sh -h

2018/ciura/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -11,14 +11,14 @@ below for more details.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < text
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -32,7 +32,7 @@ useful bug fix.
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -44,7 +44,7 @@ Use `prog.alt` as you would `prog` above.
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 

2018/endoh1/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < textfile > output.gif
 ```
 
@@ -16,7 +16,7 @@
 
 To see the input files and feed them to the program, redirecting to GIF files:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -40,7 +40,7 @@ least 2MiB of memory to run in.
 
 This program generates an animated GIF from a plain text.  Run:
 
-```<!---sh-->
+``` <!---sh-->
     cc -o prog prog.c
     ./prog < invisible.txt > invisible.gif
 ```
@@ -51,14 +51,14 @@ letters that leave the mark and ones that do not?
 
 Other examples:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < golem.txt > golem.gif
     ./prog < smily.txt > smily.gif
 ```
 
 The program itself has a hidden message.
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < prog.c > prog.gif
 ```
 

2018/endoh2/README.md

@@ -1,20 +1,20 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

2018/ferguson/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -10,14 +10,14 @@ monkey Eric. See [Alternate code](#alternate-code) below.
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 
     # For those who believe in '"intelligent" design' or want to see how easy it is
@@ -47,7 +47,7 @@ about this under the [keyboards](#keyboards) section, briefly referred to in the
 
 ### Alternate build:
 
-```<!---sh-->
+``` <!---sh-->
     make alt
 ```
 
@@ -59,7 +59,7 @@ Use `weasel.alt` as you would `weasel` above.
 
 ### Alternate try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 
     # For those who believe in '"intelligent" design' or want to see how easy it is
@@ -80,7 +80,7 @@ detail in the [S, M and N Constants](#constants) section. The script above will
 make use of some of these.
 
 
-```<!---sh-->
+``` <!---sh-->
     ./try.alt.sh
 ```
 
@@ -107,7 +107,7 @@ while using more Cenozoic minded code migration, read [rpm.html](rpm.html).
 
 If you find yourself in an evolutionary dead end, try:
 
-```<!---sh-->
+``` <!---sh-->
     man ./weasel.1
 ```
 
@@ -139,7 +139,7 @@ texts. To resolve this I think the best way is referencing the judges' remarks:
 if you want a quick rundown of the entry try what they suggest and view the man
 page (it explains all the options and describes the program briefly):
 
-```<!---sh-->
+``` <!---sh-->
     man ./weasel.man
 ```
 
@@ -444,7 +444,7 @@ has more than one word (that is it contains spaces) or anything else interpreted
 specially by your shell e.g. parentheses. For instance if you just want to find
 `METHINKS` you could do one of:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel METHINKS
     ./weasel "METHINKS"
     ./weasel 'METHINKS'
@@ -452,14 +452,14 @@ specially by your shell e.g. parentheses. For instance if you just want to find
 
 If you wanted `YOU ARE A MONKEY`:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel "YOU ARE A MONKEY"
     ./weasel 'YOU ARE A MONKEY'
 ```
 
 If you do one of:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel "METHINKS IT IS A" "MONKEY"
     ./weasel METHINKS IT IS A MONKEY
 ```
@@ -472,7 +472,7 @@ If you actually do want to search for a string starting with a `-` you must
 disable further parsing of options by using the `-` option itself; for
 example if you were to do any of:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel -q- -- -test
     ./weasel -q- -test
     ./weasel -q -- -test
@@ -480,7 +480,7 @@ example if you were to do any of:
 
 The target string will be: `-TEST`. This means though that here:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel -q -- -test -r5
 ```
 
@@ -498,7 +498,7 @@ are equivalent:
 
 As for the caveat I referenced what does the following do?
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel -qr 5
 ```
 
@@ -510,7 +510,7 @@ note on the parsing of the `-` option; if the program is currently parsing
 the other options are in the command line it might still parse the options. Thus
 you have:
 
-```<!---sh-->
+``` <!---sh-->
     $ ./weasel -qr-r5
     quiet output
     mutation rate out of range
@@ -522,14 +522,14 @@ you have:
 Similarly this would set quiet output, then an invalid mutation rate and then a
 mutation rate of 5:
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel --qrr5
 ```
 
 
 If you were instead to do one of (for example):
 
-```<!---sh-->
+``` <!---sh-->
     ./weasel -q -- -r
     ./weasel -q -q- -r
 ```
@@ -568,7 +568,7 @@ requested?  There are at least two ways to go about it: I took the monkey safe
 ('fool safe') method; *if you explicitly request monkey mode you cannot disable
 it in the same invocation of `weasel`!
 
-```<!---sh-->
+``` <!---sh-->
     $ ./weasel -qr101r5r101r1r test
     quiet output
     mutation rate out of range
@@ -633,7 +633,7 @@ in monkey mode.
 
 Another example:
 
-```<!---sh-->
+``` <!---sh-->
     $ ./weasel -q -r101 test -r5
     quiet output
     mutation rate out of range
@@ -649,7 +649,7 @@ which means that it'll use the genetic algorithm.
 
 One more example of monkey mode:
 
-```<!---sh-->
+``` <!---sh-->
     $ ./weasel -q -mr101 test -r5
     quiet output
     mutation rate out of range
@@ -771,13 +771,13 @@ with.
 
 Try:
 
-```<!---sh-->
+``` <!---sh-->
     make test
 ```
 
 This will essentially make sure the program is compiled and then do:
 
-```<!---sh-->
+``` <!---sh-->
     chmod +x test.sh
     ./test.sh
 ```
@@ -793,7 +793,7 @@ processed).
 You can pass additional options directly to the script but remember that it
 stops when there are no more strings in the file - so if you try:
 
-```<!---sh-->
+``` <!---sh-->
     ./test.sh -q test
 ```
 
@@ -825,7 +825,7 @@ program prints an error message and then exits (returning 1). But since the
 keyboard doesn't have `'\n'` if you were to type a `'` and send a
 `'\n'` before the closing `'` you might see something like:
 
-```<!---sh-->
+``` <!---sh-->
     $ ./weasel '!!
     > '
 
@@ -858,7 +858,7 @@ as well as some C keywords.
 
 2.  The way `main()` is declared is:
 
-```<!---c-->
+``` <!---c-->
     /* Special C main() handler (encapsulation): */
     #define r(main) main
     r(k main(k a, E **V)) {
@@ -952,7 +952,7 @@ somewhere!).
 The Makefile simplifies how to reconfigure this value with the variable
 `MAX_SIZE`:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber MAX_SIZE=55 all
 ```
 
@@ -965,7 +965,7 @@ number attempts without waiting for a very long time.
 The Makefile simplifies how to reconfigure this value with the variable
 `MAX_ATTEMPTS`:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber MAX_ATTEMPTS=100 all
 ```
 
@@ -982,7 +982,7 @@ and the larger the values the more memory it'll require.
 The Makefile simplifies how to reconfigure this value with the variable
 `OFFSPRING`:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber OFFSPRING=55 all
 ```
 
@@ -993,7 +993,7 @@ Skip to [Portability](#portability).
 
 The following options **must always be passed to the compiler:**
 
-```<!---sh-->
+``` <!---sh-->
     -DQ='typedef' -D'g(o)'='goto o;' -D'w(x)'="x:" -D'H(main)'='r(main)'
 ```
 
@@ -1003,13 +1003,13 @@ which running `make` will always do.
 If you want to increase the number of offspring to `50` (`N`) and the size of the
 chromosome to `75` (`S`) you would do:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber OFFSPRING=50 MAX_SIZE=75 everything
 ```
 
 If you wanted to change `N` to `3`:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber OFFSPRING=3 everything
 ```
 
@@ -1020,7 +1020,7 @@ result. Remember too that `S` (`MAX_SIZE`) cannot be less than `38`. Both `S` an
 
 If you wanted to change the maximum number attempts to 100 you could do:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber MAX_ATTEMPTS=100 everything
 ```
 
@@ -1038,7 +1038,7 @@ Originally I tested it on the below systems.
 
 #### Fedora 26:
 
-```<!---sh-->
+``` <!---sh-->
     $ clang --version|head -n1
     clang version 4.0.1 (tags/RELEASE_401/final)
     $ gcc --version|head -n1
@@ -1051,7 +1051,7 @@ Originally I tested it on the below systems.
 
 #### CentOS Linux release 7.4.1708 (Core)
 
-```<!---sh-->
+``` <!---sh-->
     $ clang --version|head -n1
     clang version 3.4.2 (tags/RELEASE_34/dot2-final)
     $ gcc --version|head -n1
@@ -1064,7 +1064,7 @@ Originally I tested it on the below systems.
 
 #### Fedora 27:
 
-```<!---sh-->
+``` <!---sh-->
     $ clang --version|head -n1
     clang version 5.0.1 (tags/RELEASE_501/final)
     $ gcc --version|head -n1
@@ -1080,7 +1080,7 @@ Originally I tested it on the below systems.
 System Version: macOS 10.13.4 (17E199)
 Kernel Version: Darwin 17.5.0
 
-```<!---sh-->
+``` <!---sh-->
     $ gcc -v
     Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
     Apple LLVM version 9.1.0 (clang-902.0.39.1)
@@ -1209,7 +1209,7 @@ When we found others were actually trying to programs with A, we quickly added
 additional cryptic features and evolved into B, BCPL, and finally C. We stopped
 when we got a clean compile on the following syntax:
 
-```<!---c-->
+``` <!---c-->
     for(;P("\n"),R=;P("|"))for(e=C;e=P("_"+(*u++/
     8)%2))P("|"+(*u/4)%2);
 ```
@@ -1252,7 +1252,7 @@ is a lack of common sense but since he was part of its creation I don't think
 it's a bad thing; **on the contrary it makes all of us C programmers even more
 talented! :)** I do wonder if he tested that bit of C code though:
 
-```<!---c-->
+``` <!---c-->
     for(;P("\n"),R=;P("|"))for(e=C;e=P("_"+(*u++/
     8)%2))P("|"+(*u/4)%2);
 ```

2018/giles/README.md

@@ -4,21 +4,21 @@ This entry requires SDL2 to be installed. See [FAQ 3.8: How do I compile an
 IOCCC entry that requires SDL1 or SDL2?](../../faq.html#SDL) if you don't have it
 installed and don't know how to do so.
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog ioccc.txt
 
     ./prog prog.c

2018/hou/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -18,7 +18,7 @@ For more detailed information see [2018 hou bugs](../../bugs.html#2018_hou).
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < input.json > output.html
 ```
 
@@ -27,7 +27,7 @@ View `output.html` in a browser.
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

2018/mills/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -8,7 +8,7 @@ If you wish to save state so that you can run the program and keep files changed
 (for instance you don't want to compile `mullender.c` again) you can compile it
 like:
 
-```<!---sh-->
+``` <!---sh-->
     make clobber SAVE=1 all
 ```
 
@@ -31,14 +31,14 @@ For more detailed information see [2018 mills bugs](../../bugs.html#2018_mills).
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
@@ -47,7 +47,7 @@ At the `>boot` prompt, type return.
 At the `:` prompt, type `rk(0,0)rkunix` and wait for it to initialise itself.
 Now try typing:
 
-```<!---sh-->
+``` <!---sh-->
     cat > prog.c
     main(){ printf("Hello, world!\n"); }
     ^D
@@ -59,7 +59,7 @@ where `^D` is EOF.
 
 Next try:
 
-```<!---sh-->
+``` <!---sh-->
     cc mullender.c
     a.out
 ```
@@ -81,7 +81,7 @@ Do small machines only need small programs?  This program weighs in at just
 This program can take you back to the start of everything, it is possible to
 run v0. Just type:
 
-```<!---sh-->
+``` <!---sh-->
     ./v0
 ```
 
@@ -91,7 +91,7 @@ You will be greeted with a familiar prompt of "login". The username and
 password are "dmr" and "dmr". To make things more familiar you'll need to
 create '.' as it hasn't been invented yet on this image!
 
-```<!---sh-->
+``` <!---sh-->
     @ ln dd dmr .
 ```
 
@@ -102,7 +102,7 @@ together like `ops.s bl.s hello.s bi.s` (in that order) to produce a.out!
 But wait, we said this was the start of it all! This program can also run a
 program that replaces an even larger machine that can run BSD 2.9. To start this,
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
@@ -118,7 +118,7 @@ shown earlier.
 
 But wait, there is even more!  Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./v6
 ```
 
@@ -220,7 +220,7 @@ only a quarter of a century ago -- how much could things have changed?).
 Let's try some:
 
 
-```<!---sh-->
+``` <!---sh-->
     # ls
     .cshrc       .profile     boot         hkunix       mnt          tmp
     .login       2.9stamp     dev          lib          mullender.c  unix

2018/poikola/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog
 ```
 
@@ -17,7 +17,7 @@
 On a terminal that supports 24 bit color, has black background, and size at
 least 125x38, try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -40,13 +40,13 @@ And those in the deep south might wish to go north for a better view.
 
 ### How to build:
 
-```<!---sh-->
+``` <!---sh-->
     cc -o prog -std=gnu11 -O3 prog.c
 ```
 
 or
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 

2018/vokes/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -18,14 +18,14 @@ For more detailed information see [2018 vokes bugs](../../bugs.html#2018_vokes).
 
 ## To use:
 
-```<!---sh-->
+``` <!---sh-->
     ./prog < file.txt
 ```
 
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 

2018/yang/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```<!---sh-->
+``` <!---sh-->
     make
 ```
 
@@ -10,7 +10,7 @@
 The author suggested that after compilation one should look at the generated
 files. For instance:
 
-```<!---sh-->
+``` <!---sh-->
     less generated1.c
     less generated2.c
     less generated3.c
@@ -19,7 +19,7 @@ files. For instance:
 
 ## Try:
 
-```<!---sh-->
+``` <!---sh-->
     ./try.sh
 ```
 
@@ -44,7 +44,7 @@ of `./left`, `./right` and `./shift` and the additionally generated programs.
 
 The final message can be revealed using
 
-```<!---sh-->
+``` <!---sh-->
     ./msg9 < prog.c
 ```
 
@@ -59,7 +59,7 @@ But what combinations will generate `./msg3`, `./msg4`, `./msg5`, `./msg6`,
 `Nuko` is a text rotator: given some text in `stdin`, `Nuko` will write the
 same text to `stdout`, but rotated 90 degrees counterclockwise.
 
-```<!---sh-->
+``` <!---sh-->
     cc prog.c -o left
     ./left < input.txt > rotated_counterclockwise.txt
 ```
@@ -68,7 +68,7 @@ Due to static memory allocation, only the first 1K columns by 1K rows
 are rotated, the rest are silently ignored.  But fear not, a separate
 tool with dynamic memory allocation is included:
 
-```<!---sh-->
+``` <!---sh-->
     ./left < prog.c > r1.c
     cc r1.c -o right
     ./right < input.txt > rotated_clockwise.txt
@@ -83,7 +83,7 @@ rotate counterclockwise once more, we get another program.  This
 program outputs a single message to `stdout`, which is the name of the
 series that `Nuko` came from.
 
-```<!---sh-->
+``` <!---sh-->
     ./left < prog.c | ./left > r2.c
     cc r2.c -o msg0
     ./msg0
@@ -92,7 +92,7 @@ series that `Nuko` came from.
 There is one final rotation, which produces a tool that removes
 leading whitespaces:
 
-```<!---sh-->
+``` <!---sh-->
     ./left < prog.c | ./left | ./left > r3.c
     cc r3.c -o shift
     ./shift < input.txt > no_leading_space.txt
@@ -112,7 +112,7 @@ side).  This shifted code behaves slightly different from the original
 program.  For example, here are two more messages that can be
 produced:
 
-```<!---sh-->
+``` <!---sh-->
     ./shift < prog.c | ./right > msg1.c && gcc msg1.c -o msg1 && ./msg1
     ./shift < prog.c | ./left > msg2.c && gcc msg2.c -o msg2 && ./msg2
 ```