Makefile

CC=clang
CFLAGS=-Wall -Wextra -pedantic -std=c89

LIBS=-lXmuu -lX11 -lXcursor
SRC=xfetchname.c
OBJS=$(SRC:.c=.o)

xfetchname: $(OBJS) 
	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) $(LIBS) -o $@

clean:
	rm -f $(OBJS) xfetchname

xfetchname.c

/** 
  Boilerplate (everything except 5 lines or so) 
  stolen from xsetroot, rest by Jan Winkelmann <[email protected]> 

I don't care what you do with this, just don't blame me if it breaks stuff.
**/

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <stdio.h>
#include <stdlib.h>

#define Dynamic 1

static char *program_name;
static Display *dpy;
static int screen;
static Window root;
static int save_colors = 0;
static int unsave_past = 0;
static Pixmap save_pixmap = (Pixmap)None;

static void FixupState(void);


int
main() 
{
    char *display_name = NULL;
    char *name = NULL;

name = malloc(64);
if(!name) 
fprintf(stderr, "unable to allocate memory"), exit(3);

    dpy = XOpenDisplay(display_name);
    if (!dpy) {
fprintf(stderr, "%s:  unable to open display '%s'\n",
program_name, XDisplayName (display_name));
exit (2);

    }

    screen = DefaultScreen(dpy);
    root = RootWindow(dpy, screen);
  
XFetchName(dpy, root, &name);
name[63]=NULL // dumb way to protect against buffer overflows.
printf("%s", name);

    FixupState();
    XCloseDisplay(dpy);
    exit (0);
}


/* Free past incarnation if needed, and retain state if needed. */
static void
FixupState(void)
{
    Atom prop, type;
    int format;

    unsigned long length, after;
    unsigned char *data;

    if (!(DefaultVisual(dpy, screen)->class & Dynamic))
unsave_past = 0;
    if (!unsave_past && !save_colors)
return;
    prop = XInternAtom(dpy, "_XSETROOT_ID", False);
    if (unsave_past) {    
(void)XGetWindowProperty(dpy, root, prop, 0L, 1L, True, AnyPropertyType,
 &type, &format, &length, &after, &data);
if ((type == XA_PIXMAP) && (format == 32) &&
    (length == 1) && (after == 0))
    XKillClient(dpy, *((Pixmap *)data));
else if (type != None)
    fprintf(stderr, "%s: warning: _XSETROOT_ID property is garbage\n",
    program_name);
    }
    if (save_colors) {
if (!save_pixmap)
    save_pixmap = XCreatePixmap(dpy, root, 1, 1, 1);
XChangeProperty(dpy, root, prop, XA_PIXMAP, 32, PropModeReplace,
(unsigned char *) &save_pixmap, 1);
XSetCloseDownMode(dpy, RetainPermanent);
    }
}