From 982273b9d71375806bcb2049ae2bf48e24caed5b Mon Sep 17 00:00:00 2001
From: Jeremy Baxter <jeremy@baxters.nz>
Date: Tue, 18 Jun 2024 18:41:30 +1200
Subject: [PATCH] esv: detect passage line length based on terminal width

Implements: https://todo.sr.ht/~jeremy/esv/2
---
 esv.d | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/esv.d b/esv.d
index 5caf3d8..dfa7dc5 100644
--- a/esv.d
+++ b/esv.d
@@ -44,6 +44,7 @@ string CFlag;        /* config */
 bool   fFlag, FFlag; /* footnotes */
 bool   hFlag, HFlag; /* headings */
 int    lFlag;        /* line length */
+bool   lFlagSpecified;
 bool   nFlag, NFlag; /* verse numbers */
 bool   rFlag, RFlag; /* passage references */
 string sFlag;        /* search passages */
@@ -70,7 +71,7 @@ main(string[] args)
 		import core.sys.openbsd.unistd : pledge;
 		import std.string : toStringz;
 
-		promises = toStringz("stdio rpath wpath cpath inet dns proc exec prot_exec");
+		promises = toStringz("stdio rpath wpath cpath inet dns tty proc exec prot_exec");
 		pledge(promises, null);
 	}();
 
@@ -87,7 +88,7 @@ main(string[] args)
 			"C", &CFlag,
 			"F", &FFlag, "f", &fFlag,
 			"H", &HFlag, "h", &hFlag,
-			"l", &lFlag,
+			"l", &onLineLength,
 			"N", &NFlag, "n", &nFlag,
 			"R", &RFlag, "r", &rFlag,
 			"s", &sFlag,
@@ -100,8 +101,6 @@ main(string[] args)
 			"missing argument for option " ~ e.extractOpt());
 
 		die(e.msg); /* catch-all */
-	} catch (ConvException e) {
-		die("illegal argument to -l option -- must be integer");
 	}
 
 	if (VFlag) {
@@ -225,7 +224,8 @@ key = %s
 	/* Get line-length ([passage]) */
 	try
 		esv.opts.i["line-length"] =
-			ini["passage"].keyAs!int("line-length", 0);
+			lFlagSpecified ? lFlag :
+			ini["passage"].keyAs!int("line-length", terminalColumns());
 	catch (INITypeException e)
 		die(configPath ~ ": " ~ e.msg);
 
@@ -237,7 +237,6 @@ key = %s
 	if (HFlag) esv.opts.b["include-headings"]           = false;
 	if (NFlag) esv.opts.b["include-verse-numbers"]      = false;
 	if (RFlag) esv.opts.b["include-passage-references"] = false;
-	if (lFlag != 0) esv.opts.i["line-length"] = lFlag;
 
 	try
 		writeln(esv.getPassage(args[1].parseBook(), args[2]));
@@ -263,6 +262,17 @@ die(string mesg) @trusted
 	exit(1);
 }
 
+private ushort
+terminalColumns() @trusted
+{
+	import core.sys.posix.sys.ioctl;
+
+	winsize w;
+
+	ioctl(1, TIOCGWINSZ, &w);
+	return w.ws_col > 72 ? 72 : w.ws_col;
+}
+
 private void
 enforceDie(A...)(bool cond, string fmt, A a)
 {
@@ -280,6 +290,16 @@ extractOpt(in GetOptException e)
 	return e.msg.matchFirst("-.")[0];
 }
 
+private void
+onLineLength(string flag, string value)
+{
+	lFlagSpecified = true;
+	try
+		lFlag = value.to!int();
+	catch (ConvException e)
+		die("illegal argument to -l option -- must be a positive integer");
+}
+
 private string
 parseBook(in string book)
 {