Improve make fullscreen in 2019/duble + formatting

The Makefile now uses the script fullscreen.sh which should also be
slightly more portable in that it doesn't rely on both stty(1) and
sed(1). Instead it relies on tput(1). Like the Makefile did for stty(1),
the script checks for tput(1). But rather than suggesting that the user
manually update the Makefile (without instructions) it now gives a
command that one can use to do the equivalent. This is assuming that the
environmental variables LINES and COLUMNS exist. Unfortunately these
variables are not available to scripts so it can't be done
automatically. This script also (if tput(1) cannot be found) shows a
more general way of how to change the size of the editor (the README.md
also does this). One can do something like

    make clobber LINES=20 COLUMNS=20 all

to get a 20 x 20 editor.

The fullscreen.sh script was added to simplify the above procedure.

The README.md file was format/typo checked.

I updated the bugs.md as well: I noticed another condition where the
program can become locked, forcing one to have to kill it. At the same
time I improved the way to find sockets that are left by the program
(the way before had the problem that other dot files with all cap
letters could be found) and also an improved way to delete them (which
there is no Makefile rule to do). Now bugs.md discusses both the locking
and the sockets being left in the directory.

2019/duble/Makefile

@@ -146,16 +146,8 @@ ${PROG}:
 check-os: check-os.sh
 	${SHELL} ./check-os.sh ${LINES} ${COLUMNS}
 
-error-stty:
-	@echo "No stty command here. Please manually specify size in the Makefile." >&2 ; false
-
-has-stty:
-	which stty >/dev/null || ${MAKE} error-stty
-
-fullscreen: has-stty
-	${MAKE} ${PROG} \
-	LINES=`stty size | sed -s 's/ .*$$//'` \
-	COLUMNS=`stty size | sed -s 's/^.* //'`
+fullscreen: fullscreen.sh
+	./$<
 
 Darwin: ${PROG}.c
 	${RM} -f $@

2019/duble/README.md

@@ -4,6 +4,9 @@
 make
 ```
 
+There is an alternate version, the original, which does not work well in macOS.
+See [Alternate code](#alternate-code) below if you are curious.
+
 
 ### Bugs and (Mis)features:
 
@@ -37,54 +40,70 @@ Open another window / terminal.
 
 Open more terminals and repeat...
 
+You might also wish to try a full screen size. For this try:
+
+```sh
+make clobber fullscreen
+```
+
+Alternatively, if you want to change the size, do something like:
+
+```sh
+make clobber LINES=20 COLUMNS=20 all
+```
+
+The author provided us with the following table for use:
+
+---
+
+* **Arrow keys**: move cursor.
+* `p` key: enter *pen* mode (type **p** again to return to the default *move*
+mode).
+* `l` key: enter *line* mode (type **l** again to validate the line and return
+to the *move* mode).
+* `c` key: cycle through a small set of different *colors*.
+* `q` key: quit the editor. The drawing is automatically saved.
+
+The mode and current color is indicated at the bottom left corner of
+the editor.
+
+After editing the file and quitting, try:
+
+```sh
+/tmp/drawing
+```
+
+i.e. execute the file.
+
+
+---
+
 WARNING: if the file is deleted it might lock any session still in use. These
-will have to be killed from another shell session or by closing the terminal
-tab.
-
-This is supposed to happen.  As is written in the
-[The Jargon File](http://catb.org/jargon/html/F/feature.html):
-
-```
-That's not a bug, that's a feature.
-```
+will have to be killed from another shell session or by closing the terminal tab
+(in other words don't do this from the console!). If the file cannot be opened
+in the beginning this will also happen. This is discussed in [2019 duble in
+bugs.md](/bugs.md#2019-duble).
 
 NOTE: this entry might leave sockets lying about in the current working
-directory which you'll have to delete manually. Here's an example in macOS:
-
-```sh
-$ ls -al
-srwxr-xr-x   1 ioccc  staff      0  6 Apr 08:19 .BDHFHALG
-srwxr-xr-x   1 ioccc  staff      0  6 Apr 08:15 .CGGHAMGC
-srwxr-xr-x   1 ioccc  staff      0  6 Apr 08:16 .CMDGAELH
-...
-```
-
-To get a list of files with this glob try:
-
-```sh
-ls -al|awk '{print $NF}'|grep -E '^\.[A-Z]{2,}'
-```
-
-To delete them you can do:
-
-```sh
-find . -name '.[A-Z]*' -delete
-```
-
-though one might want to check that the program is not currently running. :-)
+directory which you'll have to delete manually. This is also discussed in [2019
+duble in bugs.md](/bugs.md#2019-duble).
 
 
 ## Alternate code:
 
-An alternate version of this entry, [prog.alt.c](prog.alt.c), is provided.  This alternate
-code might not work as well on macOS.
+An alternate version of this entry, [prog.alt.c](prog.alt.c), is provided.  This
+alternate code might not work as well in macOS.
 
-To compile this alternate version:
+
+### Alternate build:
 
 ```sh
 make alt
 ```
 
+
+### Alternate use:
+
 Use `prog.alt` as you would `prog` above.
 
 
@@ -96,6 +115,7 @@ or `l` (they toggle).
 
 ## Author's remarks:
 
+
 ### Introduction:
 
 This program is a **graphics editor**, running in the terminal.
@@ -103,10 +123,11 @@ This program is a **graphics editor**, running in the terminal.
 It provides **collaborative** features: one can join the drawing session
 of someone else by just opening the same file!
 
+
 ### Getting started:
 
 The program can run on Linux, FreeBSD, macOS, and in most terminals.
-See section 'Limits, Portability' for more info.
+See section [Limits, Portability](#limits-portability) for more info.
 
 To build, type `make` (assuming gcc) or `make CC=clang`.
 
@@ -116,14 +137,15 @@ Then you can start the program. It expects a file path as its first argument:
 ./prog /tmp/drawing
 ```
 
-(If not started this way, `prog` will refuse to start.)
+(If not started this way, with a file, `prog` will refuse to start.)
 
 If the file does not exist, you will start with a blank drawing.
 
 If someone else (or another *instance of yourself*, maybe?) is already
 editing this file, you will join the session!
 
-### Edition features:
+
+### Edit features:
 
 * **arrow keys**: move cursor.
 * `p` key: enter *pen* mode (type **p** again to return to the default *move* mode).
@@ -134,6 +156,7 @@ editing this file, you will join the session!
 The mode and current color is indicated at the bottom left corner of
 the editor.
 
+
 ### Bonus features:
 
 * If you just want to display the content of a drawing file, you do not
@@ -152,7 +175,7 @@ You will probably have a hard time analyzing this entry, because:
 *   Code coverage of single vs multi-user sessions is more or less the same. :-)
 *   Code coverage when using *move*, *pen* or *line* modes is almost the same.
     (so, is there a Bresenham algorithm somewhere??)
-*   Some OS resource values and stdlib call results are inferred.
+*   Some OS resource values and `stdlib.h` call results are inferred.
 *   Whenever possible, variable names are reused.
 *   You might start analyzing escape code sequences right now, but warming up
     your brain is actually recommended. Start with a simple question such as:
@@ -167,6 +190,7 @@ variable, instead? (spoiler: <http://c-faq.com/ansi/constasconst.html>)
 If your keyboard has no arrow keys, you can probably find alternate keys by
 reading the source code.
 
+
 ### Limits, Portability:
 
 I tested the program on several Linux systems, on FreeBSD 12, and on
@@ -184,8 +208,10 @@ inverse video mode, and movement escape codes, e.g. `xterm`, `gnome-terminal`,
 Note: the drawing files `prog` generates are probably even more portable than
 `prog` itself!
 
+
 ### Drawing area size:
 
+
 #### The drawing area size is set at compilation time:
 
 The default size is the one of my xterm (see top of Makefile).
@@ -203,28 +229,27 @@ IMPORTANT NOTES:
     so any peer reaching the session should have a terminal with the same
     size or larger.
 
-### prog.c vs prog.alt.c
+### [prog.c](prog.c) vs [prog.alt.c](prog.alt.c)
 
 The file [prog.alt.c](prog.alt.c) is the one I submitted.
 
-Judges proposed a small update: the program was using macro `FD_SET` inside an
+The judges proposed a small update: the program was using macro `FD_SET` inside an
 expression, which breaks compilation on macOS. Wrapping this macro into a
 function was enough to fix this compilation issue.
 
 However, that was not enough to make the program work on macOS. If you analyse
 the program you will see that it heavily relies on OS resources. And, for this
 first version of the program, you even needed to increase default `sysctl`
-parameters to make it work on FreeBSD (this was the purpose of file `check-os.sh`).
-I tried hard to tune macOS the same, but failed.
+parameters to make it work on FreeBSD (this was the purpose of file
+[check-os.sh](check-os.sh)). I tried hard to tune macOS the same, but failed.
 
-The simple fact Judges proposed this update meant they wish it could work on Mac.
-And if judges wish something, it **has to** be done. ;)
-So I refactored a little more the program to reduce OS resources consumption.
-Or maybe not reduce consumption, but consume them differently...
-And I obtained `prog.c`. With this version, no need to touch `sysctl` parameters,
-and it works on macOS too!
-I must confess it was challenging to remain below the size limit with this little
-change.
+The simple fact the Judges proposed this update meant they wish it could work on
+Mac.  And if the judges wish something, it **has to** be done. ;) So I
+refactored a little more the program to reduce OS resources consumption.  Or
+maybe not reduce consumption, but consume them differently...  And I obtained
+[prog.c](prog.c). With this version, no need to touch `sysctl` parameters, and
+it works on macOS too!  I must confess it was challenging to remain below the
+size limit with this little change.
 
 
 ## Copyright and CC BY-SA 4.0 License:

2019/duble/fullscreen.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+#
+# Try and determine full screen size for make fullscreen rule.
+#
+TPUT="$(type -P tput)"
+
+if [[ -z "$TPUT" ]]; then
+    echo "No tput found, try:" >&2
+    echo >&2
+    echo "  make clobber LINES=\$LINES COLUMNS=\$COLUMNS all" >&2
+    echo >&2
+    echo "or to specify a specific size:" >&2
+    echo >&2
+    echo "  make clobber LINES=20 COLUMNS=20 all" >&2
+    echo >&2
+    echo "or whatever you wish the lines and columns to be." >&2
+    exit 1
+else
+    make clobber all LINES="$($TPUT lines)" COLUMNS="$($TPUT cols)"
+fi

bugs.md

@@ -3348,9 +3348,16 @@ ideal if this was not the case.
 ### Source code: [2019/duble/prog.c](2019/duble/prog.c)
 ### Information: [2019/duble/README.md](2019/duble/README.md)
 
-This program will very likely leave sockets lying about in the current working
-directory. For instance [Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson)
-showed us this:
+There are two things to be aware of with this entry.
+
+If the file being used (to draw) is deleted it might lock any session still in
+use. These will have to be killed from another shell session or by closing the
+terminal tab. This will also happen if the file cannot be opened in the
+beginning.
+
+This program will also very likely leave sockets lying about in the current
+working directory. For instance [Cody Boone
+Ferguson](/winners.html#Cody_Boone_Ferguson) showed us this:
 
 ```sh
 $ ls -al |grep '^s'
@@ -3365,22 +3372,22 @@ This is NOT a bug and you'll have to (at least at this time?) delete the files
 manually. You shouldn't have to worry about these being added to git: it seems
 to ignore sockets (it did at least in macOS).
 
-NOTE: to get a list of files with this glob try:
+He provides the following tips on this situation. A simpler way to find sockets
+in the directory:
 
 ```sh
-ls -al |awk '{print $NF}' | grep -E '^\.[A-Z]+'
+file .*|grep socket|cut -f1 -d:
 ```
 
 To delete them you can do:
 
 ```sh
-find . -name '.[A-Z]*' -delete
+find . -exec file '{}' \;|grep socket|cut -f 1 -d: | xargs rm -f
 ```
 
 though one might want to check that the program is not currently running. :-)
 
 
-
 ## 2019 endoh
 
 ### STATUS: INABIAF - please **DO NOT** fix

thanks-for-help.md

@@ -4194,6 +4194,19 @@ was to only correct spelling and only some, not to change wording or anything
 else).
 
 
+## <a name="2019_duble"></a>[2019/duble](/2019/duble/prog.c) ([README.md](/2019/duble/README.md]))
+
+[Cody](#cody) made the `make fullscreen` more portable by not relying on
+`stty(1)` and `sed(1)` but rather it just uses `tput(1)`. He also made it so
+that if `tput(1)` is not found it tells the user an easier way to compile the full
+screen size rather than having to modify the Makefile. This done with a script,
+[fullscreen.sh](/2019/duble/fullscreen.sh), to simplify the Makefile and provide
+an easy way to tell the user how to compile it, assuming that the environmental
+variables `LINES` and `COLUMNS` are set. But even if they're not set it explains
+how to easily compile the program to a specific size. Note that `LINES` and
+`COLUMNS` is not available to scripts so it can't make use of them that way.
+
+
 ## <a name="2019_endoh"></a>[2019/endoh](/2019/endoh/prog.c) ([README.md](/2019/endoh/README.md]))
 
 As this is a backtrace quine having the optimiser enabled is not a good idea so