From 9ce669ca8d9bfffc4a7626de15da24f5b27ba809 Mon Sep 17 00:00:00 2001
From: Justinas Grigas <dev@jstnas.com>
Date: Sat, 9 May 2026 14:20:00 +0100
Subject: [PATCH] xresources: runtime configuration using X resources

---
 config.def.h | 36 +++++++++++++++++++++++++
 x.c          | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)

diff --git a/config.def.h b/config.def.h
index 2cd740a..62e88cc 100644
--- a/config.def.h
+++ b/config.def.h
@@ -472,3 +472,39 @@ static char ascii_printable[] =
 	" !\"#$%&'()*+,-./0123456789:;<=>?"
 	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
 	"`abcdefghijklmnopqrstuvwxyz{|}~";
+
+/* X resources to update */
+static const XResPref resources[] = {
+	/* name                    type     address */
+	{ "st.font",               STRING,  &font },
+	{ "st.color0",             STRING,  &colorname[0] },
+	{ "st.color1",             STRING,  &colorname[1] },
+	{ "st.color2",             STRING,  &colorname[2] },
+	{ "st.color3",             STRING,  &colorname[3] },
+	{ "st.color4",             STRING,  &colorname[4] },
+	{ "st.color5",             STRING,  &colorname[5] },
+	{ "st.color6",             STRING,  &colorname[6] },
+	{ "st.color7",             STRING,  &colorname[7] },
+	{ "st.color8",             STRING,  &colorname[8] },
+	{ "st.color9",             STRING,  &colorname[9] },
+	{ "st.color10",            STRING,  &colorname[10] },
+	{ "st.color11",            STRING,  &colorname[11] },
+	{ "st.color12",            STRING,  &colorname[12] },
+	{ "st.color13",            STRING,  &colorname[13] },
+	{ "st.color14",            STRING,  &colorname[14] },
+	{ "st.color15",            STRING,  &colorname[15] },
+	{ "st.foreground",         STRING,  &colorname[258] },
+	{ "st.background",         STRING,  &colorname[259] },
+	{ "st.cursorColor",        STRING,  &colorname[256] },
+	{ "st.cursorColorReverse", STRING,  &colorname[257] },
+	{ "st.termname",           STRING,  &termname },
+	{ "st.shell",              STRING,  &shell },
+	{ "st.minlatency",         INTEGER, &minlatency },
+	{ "st.maxlatency",         INTEGER, &maxlatency },
+	{ "st.blinktimeout",       INTEGER, &blinktimeout },
+	{ "st.bellvolume",         INTEGER, &bellvolume },
+	{ "st.tabspaces",          INTEGER, &tabspaces },
+	{ "st.borderpx",           INTEGER, &borderpx },
+	{ "st.cwscale",            FLOAT,   &cwscale },
+	{ "st.chscale",            FLOAT,   &chscale },
+};
diff --git a/x.c b/x.c
index d73152b..5cd6f7c 100644
--- a/x.c
+++ b/x.c
@@ -14,6 +14,7 @@
 #include <X11/keysym.h>
 #include <X11/Xft/Xft.h>
 #include <X11/XKBlib.h>
+#include <X11/Xresource.h>
 
 char *argv0;
 #include "arg.h"
@@ -45,6 +46,15 @@ typedef struct {
 	signed char appcursor; /* application cursor */
 } Key;
 
+/* Xresources preferences */
+enum XResType { STRING, INTEGER, FLOAT };
+
+typedef struct {
+	const char *name;
+	enum XResType type;
+	void *dst;
+} XResPref;
+
 /* X modifiers */
 #define XK_ANY_MOD    UINT_MAX
 #define XK_NO_MOD     0
@@ -189,6 +199,9 @@ static int match(uint, uint);
 static void run(void);
 static void usage(void);
 
+static void xresload(const XResPref *);
+static void xresupdate(void);
+
 static void (*handler[LASTEvent])(XEvent *) = {
 	[KeyPress] = kpress,
 	[ClientMessage] = cmessage,
@@ -220,6 +233,7 @@ static DC dc;
 static XWindow xw;
 static XSelection xsel;
 static TermWindow win;
+static XrmDatabase xrdb;
 
 /* Font Ring Cache */
 enum {
@@ -2023,6 +2037,63 @@ run(void)
 	}
 }
 
+void
+xresload(const XResPref *resource)
+{
+	char *type;
+	XrmValue ret;
+
+	if (!XrmGetResource(xrdb, resource->name, NULL, &type, &ret))
+		return;
+	if (ret.addr == NULL || strncmp(type, "String", sizeof("String")))
+		return;
+
+	switch (resource->type) {
+	case STRING:
+		*(char **)resource->dst = ret.addr;
+		break;
+	case INTEGER:
+		*(int *)resource->dst = strtoul(ret.addr, NULL, 10);
+		break;
+	case FLOAT:
+		*(float *)resource->dst = strtof(ret.addr, NULL);
+		break;
+	}
+}
+
+void
+xresupdate(void)
+{
+	Display *display;
+	char *resm;
+	const XResPref *p;
+
+	display = XOpenDisplay(NULL);
+	if (!display)
+		return;
+
+	resm = XResourceManagerString(display);
+	if (resm) {
+		if (xrdb)
+			XrmDestroyDatabase(xrdb);
+		xrdb = XrmGetStringDatabase(resm);
+		if (xrdb) {
+			for (p = resources; p < resources + LEN(resources); ++p)
+				xresload(p);
+		}
+	}
+	XCloseDisplay(display);
+}
+
+void
+xresreload(int signum) {
+	xresupdate();
+	xloadcols();
+	cresize(0, 0);
+	redraw();
+	xhints();
+}
+
 void
 usage(void)
 {
@@ -2096,6 +2167,9 @@ run:
 
 	setlocale(LC_CTYPE, "");
 	XSetLocaleModifiers("");
+	XrmInitialize();
+	xresupdate();
+	signal(SIGUSR1, xresreload);
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
 	tnew(cols, rows);
-- 
2.53.0