slstatus

commit a4d910945cb842864155e512e9a7641600b3c377
parent 376f9191ee9db202963237d9b994f3131cb9a0c9
Author: Santtu Lakkala <inz@inz.fi>
Date:   Wed, 23 Feb 2022 08:56:03 +0200

Add wintitle module

Wintitle module allows to grab parts of a window's title. The module
argument is a list of comma separated strings that must be present in
the window's title in order. One of the strings should be !, which
indicates the part to capture.

Diffstat:
M
Makefile
 | 
3
++-
A
components/wintitle.c
 | 
95
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
slstatus.h
 | 
3
+++

3 files changed, 100 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
@@ -27,7 +27,8 @@ COM =\
 	components/uptime\
 	components/user\
 	components/volume\
-	components/wifi
+	components/wifi\
+	components/wintitle
 
 all: slstatus
 
diff --git a/components/wintitle.c b/components/wintitle.c
@@ -0,0 +1,95 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <regex.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+#include "../util.h"
+
+static const char *getname(Window);
+static const char *grepw(Window, const char *, int *);
+const char *rematch(const regex_t *, const char *str, int *cl);
+static Display *dpy = NULL;
+static Atom netwmname;
+
+const char *
+rematch(const regex_t *re, const char *str, int *cl)
+{
+	regmatch_t m[2];
+	if (regexec(re, str, sizeof(m) / sizeof(*m), m, 0) ||
+	    m[1].rm_so == -1)
+		return NULL;
+
+	*cl = m[1].rm_eo - m[1].rm_so;
+	return str + m[1].rm_so;
+}
+
+const char *
+wintitle(const char *arg)
+{
+	int rl;
+	const char *rv;
+
+	if (!dpy) {
+		if (!(dpy = getdisplay())) {
+			warn("XOpenDisplay: Failed to open display");
+			return NULL;
+		}
+		netwmname = XInternAtom(dpy, "_NET_WM_NAME", False);
+	}
+
+	rv = grepw(DefaultRootWindow(dpy), arg, &rl);
+
+	if (!rv)
+		return NULL;
+
+	return bprintf("%.*s", rl, rv);
+}
+
+const char *
+grepw(Window win, const char *pattern, int *rl) {
+	unsigned int n;
+	Window *wins, *w, dw;
+	XWindowAttributes wa;
+	const char *rv = NULL;
+	regex_t re;
+
+	if (regcomp(&re, pattern, REG_EXTENDED))
+		goto err1;
+	if(!XQueryTree(dpy, win, &dw, &dw, &wins, &n))
+		goto err2;
+	for(w = &wins[n-1]; w >= &wins[0]; w--)
+		if(XGetWindowAttributes(dpy, *w, &wa)
+		&& !wa.override_redirect && wa.map_state == IsViewable)
+			if ((rv = rematch(&re, getname(*w), rl)))
+				break;
+
+err2:
+	XFree(wins);
+err1:
+	regfree(&re);
+
+	return rv;
+}
+
+const char *
+getname(Window win) {
+	static char buf[BUFSIZ];
+	char **list;
+	int n;
+	XTextProperty prop;
+
+	if(!XGetTextProperty(dpy, win, &prop, netwmname) || prop.nitems == 0)
+		if(!XGetWMName(dpy, win, &prop) || prop.nitems == 0)
+			return "";
+	if(!XmbTextPropertyToTextList(dpy, &prop, &list, &n) && n > 0) {
+		strncpy(buf, list[0], sizeof buf);
+		XFreeStringList(list);
+	} else
+		strncpy(buf, (char *)prop.value, sizeof buf);
+	XFree(prop.value);
+	buf[sizeof buf - 1] = '\0';
+	return buf;
+}
diff --git a/slstatus.h b/slstatus.h
@@ -82,3 +82,6 @@ const char *vol_perc(const char *card);
 /* wifi */
 const char *wifi_perc(const char *interface);
 const char *wifi_essid(const char *interface);
+
+/* wintitle */
+const char *wintitle(const char *pattern);