util  Check-in [196f94b613]

/* [ʞ] bgrd.c
 *  ~ lexi hale <lexi@hale.su>
 *  $ cc -Ofast bgrd.c -lutil -obgrd
 *  © affero general public license 3.0

 * i am angry beyond words that this program had to
 * be written
 *
 * bgrd "background read" is a tool for launching an 
 * application and retrieving the first line of output.
 * this is a nontrivial task for a number of reasons,
 * all of which are incredibly stupid, however, most
 * saliently: buffered io.
 *
 * the suckmore web browser `surf` has an option '-x'
 * which is intended to print the X window id of the
 * window it opens, so it can be captured and used in
 * scripts. so far so good.
 *
 * except unix has two distinctly different concepts
 * of IO. there's POSIX IO, and then there's libc IO.
 *
 * POSIX IO uses the shit in <fcntl.h> and <unistd.h>;
 * syscalls like read(2), write(2), and pipe(2) - the
 * good, simple shit God made unix for. this is really
 * bare-metal; these are basically C wrappers over
 * kernel syscalls. POSIX IO uses plain old ints as
 * file descriptors, and it doesn't fuck around. when
 * you say "write," god dammit, it WRITES.
 *
 * libc is a very different beast. libc has opinions.
 * libc has abstractions. libc has its own entire
 * goddamn DSL by which to specify format strings,
 * because apparently someone felt called to reinvent
 * FORTRAN except worse. printf(), you know, the first
 * function they ever teach you in C 101? (more like CS
 * 403 these days, but aghhh) it's actually a heinously
 * complicated, dangerous, slow, insecure mess that drags
 * a ridiculous amount of background bullshit into the
 * frame. such as BUFFERING.
 *
 * libc, you see, is too good to just wrap write() and
 * read(). no, it also has to decide when to SEND them.
 * this is responsible for that behavior every c coder
 * trips over eventually - you know the one, where if
 * you don't end your format string in '\n' it isn't
 * printed, sometimes even if the program exits. this
 * is not actually a POSIX thing; it's a libc thing.
 *
 * libc has a couple different kinds of buffering tactics
 * (set with setvbuf(), a function nobody seems to know
 * exists) that it uses in different circumstances.
 * the printf \n gotcha behavior is what's known as
 * "line buffering." however, because libc thinks it's
 * fucking smart or something, it's not content to just
 * pick one predictable behavior and stick to it. oh no.
 *
 * ever noticed how programs can seem to tell whether
 * they're connected to a terminal (and thus can output
 * all those fancy ansi formatting codes), or whether
 * you're redirecting their stdout to a file? that's 
 * because there's more than one kind of pipe. the kind
 * you create with pipe(2) - and the kind you create with
 * openpty(2).
 *
 * a pty is, essentially, a kind of pipe that carries
 * extra information around, the information you access
 * via ioctl and termios. it's designed to imitate a TTY,
 * so that a shell can create one, aim a process at it,
 * and then that process can draw TUIs and shit on it.
 * and some programs are designed to behave differently
 * depending on whether they're hooked up to a pipe or a
 * pty.
 *
 * libc, tragically, is among them.
 *
 * if libc notices it's hooked up to a pipe instead of a pty,
 * it will change its default buffering strategy. newlines
 * will suddenly cease flushing stdout, and libc will
 * only print its buffer in one of two circumstances: the
 * buffer is filled up, or the program exits.

 *
 * this is a problem if you are, say, trying to output a
 * handle that scripts can use to control the running

 * program.
 *
 * the `surf` developers had a couple of options. they
 * could have simply broken out the POSIX headers and

 * sent the X id to stdout with a call to write(2), the
 * correct thing to do. they could have thrown in a call
 * to setvbuf(3) to explicitly pick a buffering strategy
 * compatible with their usecase, the sensibly wrong

 * thing to do. they could have explicitly flushed stdout
 * after printf(3)'ing to it, the dumb and error-pront
 * thing to do.
 *
 * instead, they did *nothing.*
 *
 * so if you run `surf -x` from a terminal, great!
 * you'll see it print the x window id first thing.
 * you'll then try to capture it via any number of
 * increasing desperate means, all of which will fail
 * hilariously. finally, you'll spend four goddamn hours
 * after midnight reading source code and manpages and
 * frantically googling around and digging up unix lore
 * and finally, FINALLY figure out what the batshit FUCK
 * is going on, and write this goddamn utility to hack
 * around the suckmore crowd's suckitude.
 *
 * so i figured i'd save you some time.
 *
 * i am probably going to submit a PR eventually because
 * holy hell this is just so monumentally bozotic.
 *
 * in the mean time, you can use this extremely
 * no-bullshit wrapper by running `set surfwin (bgrd
 * (which surf) surf -x <params>` or whatever the bash
 * equivalent is and it will immediately launch surf in
 * the background, printing the X window and exiting
 * as soon as it hits a newline. it should be adaptable
 * to similar scenarios if you find yourself dealing with
 * similarly broken software tho.
 *
 * in conclusion, read lenin. */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

/* [ʞ] bgrd.c
 *  ~ lexi hale <lexi@hale.su>
 *  $ cc -Ofast bgrd.c -lutil -obgrd
 *  © affero general public license 3.0

 * i am  angry beyond words  that this program had  to be
 * written
 *
 * bgrd  "background read"  is  a tool  for launching  an
 * application and  retrieving the first line  of output.
 * this is  a nontrivial  task for  a number  of reasons,
 * all  of which  are  incredibly  stupid, however,  most
 * saliently: buffered io.
 *
 * the  suckmore web  browser `surf`  has an  option '-x'
 * which  is intended  to print  the X  window id  of the
 * window it  opens, so  it can be  captured and  used in
 * scripts. so far so good.
 *
 * except unix  has two distinctly different  concepts of
 * IO. there's POSIX IO, and then there's libc IO.
 *
 * POSIX IO  uses the  shit in <fcntl.h>  and <unistd.h>;
 * syscalls  like read(2),  write(2), and  pipe(2) -  the
 * good, simple  shit God made  unix for. this  is really
 * bare-metal; these are basically C wrappers over kernel
 * syscalls.  POSIX  IO  uses  plain  old  ints  as  file
 * descriptors, and it doesn't  fuck around. when you say
 * "write," god dammit, it WRITES.
 *
 * libc  is a  very different  beast. libc  has opinions.
 * libc has abstractions. libc has its own entire goddamn
 * DSL  by  which  to  specify  format  strings,  because
 * apparently  someone felt  called  to reinvent  FORTRAN
 * except worse.  printf(), you know, the  first function
 * they  ever teach  you  in  C 101?  (more  like CS  403
 * these  days,  but  aghhh) it's  actually  a  heinously
 * complicated, dangerous, slow, insecure mess that drags
 * a ridiculous  amount of  background bullshit  into the
 * frame. such as BUFFERING.
 *
 * libc, you  see, is too  good to just wrap  write() and
 * read(). no, it  also has to decide when  to SEND them.
 * this is  responsible for  that behavior every  c coder
 * trips over eventually - you know the one, where if you
 * don't end your format string in '\n' it isn't printed,
 * sometimes  even  if the  program  exits.  this is  not
 * actually a POSIX thing; it's a libc thing.
 *
 * libc has a couple different kinds of buffering tactics
 * (set with  setvbuf(), a function nobody  seems to know
 * exists) that  it uses in different  circumstances. the
 * printf  \n gotcha  behavior is  what's known  as "line
 * buffering." however, because  libc thinks it's fucking
 * smart or something, it's not  content to just pick one
 * predictable behavior and stick to it. oh no.
 *
 * ever  noticed how  programs can  seem to  tell whether
 * they're connected  to a terminal (and  thus can output
 * all  those fancy  ansi formatting  codes), or  whether
 * you're  redirecting their  stdout  to  a file?  that's
 * because there's more  than one kind of  pipe. the kind
 * you create with pipe(2) - and the kind you create with
 * openpty(2).
 *
 * a pty  is, essentially,  a kind  of pipe  that carries
 * extra information  around, the information  you access
 * via ioctl and termios. it's designed to imitate a TTY,
 * so that a  shell can create one, aim a  process at it,
 * and then  that process can  draw TUIs and shit  on it.
 * and some  programs are designed to  behave differently
 * depending on whether they're hooked  up to a pipe or a
 * pty.
 *
 * libc, tragically, is among them.
 *
 * if libc notices it's hooked up  to a pipe instead of a
 * pty, it  will change  its default  buffering strategy.
 * newlines  will  suddenly  cease flushing  stdout,  and
 * libc  will  only  print  its  buffer  in  one  of  two
 * circumstances: the buffer is filled up, or the program
 * exits.
 *
 * this is a problem if you  are, say, trying to output a

 * handle  that scripts  can use  to control  the running
 * program.
 *

 * the `surf`  developers had  a couple of  options. they
 * could  have simply  broken out  the POSIX  headers and
 * sent the X  id to stdout with a call  to write(2), the
 * correct thing to do. they  could have thrown in a call
 * to setvbuf(3) to explicitly  pick a buffering strategy

 * compatible  with  their  usecase, the  sensibly  wrong
 * thing to do. they could have explicitly flushed stdout
 * after printf(3)'ing  to it,  the dumb  and error-pront
 * thing to do.
 *
 * instead, they did *nothing.*
 *
 * so  if  you run  `surf  -x`  from a  terminal,  great!
 * you'll  see it  print  the x  window  id first  thing.
 * you'll  then  try to  capture  it  via any  number  of
 * increasing  desperate means,  all of  which will  fail
 * hilariously. finally, you'll  spend four goddamn hours
 * after midnight  reading source  code and  manpages and
 * frantically googling  around and digging up  unix lore
 * and finally, FINALLY figure  out what the batshit FUCK
 * is going  on, and write  this goddamn utility  to hack
 * around the suckmore crowd's suckitude.
 *
 * so i figured i'd save you some time.
 *
 * i am probably going to  submit a PR eventually because
 * holy hell this is just so monumentally bozotic.
 *
 * in  the   mean  time,  you  can   use  this  extremely
 * no-bullshit  wrapper  by  running `set  surfwin  (bgrd
 * (which surf)  surf -x  <params>` or whatever  the bash
 * equivalent is  and it will immediately  launch surf in
 * the background,  printing the X window  and exiting as
 * soon as it  hits a newline. it should  be adaptable to
 * similar scenarios  if you  find yourself  dealing with
 * similarly broken software tho.
 *
 * in conclusion, read lenin. */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

/* [ʞ] smake.c <c.hale.su/lexi/util>
 *  ~ lexi hale <lexi@hale.su>
 *  $ cc -Ofast smake.c -osmake
 *  © affero general public license

        	    * I N C O M P L E T E *
			| basic functionality is still |
			|  heavily  under development  |

 * a replacement  for sassc  --watch, smake  maintains an
 * in-memory  dependency graph  for  the specified  files
 * and  automatically re-compiles  them  when  they or  a
 * dependency of theirs changes

 TODO add switch to generate makefile from constructed
      graph and exit */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>

enum       e { ok, badname, nofile };
enum    kind { css, sass, scss, bad };
typedef enum { false, true } bool;

#define corebufsz 1024
char corebuf[corebufsz];
void* extbuf, * bufptr;
size_t run = 0;
#define max(a,b) (a > b ? a : b)

void* alloc(size_t sz) {
	if((bufptr + sz) < ((void*)corebuf + corebufsz)) goto mkptr;
	else {
		if (run == 0) {
			run = corebufsz;
			extbuf = malloc(run);
			bufptr = extbuf + sz;
			return extbuf;
		} else {
			if ((bufptr + sz) < (extbuf + run)) goto mkptr;
			else {
				run += max(512, sz+128);
				size_t rsz = bufptr-extbuf;
				extbuf = realloc(extbuf, run);
				bufptr = extbuf + rsz + sz;
				return bufptr - sz;
			}
		}
	}
	// this point should never be reached
	mkptr: {
		void* ret = bufptr;
		bufptr += sz;
		return ret;
	}
}



struct file {
	char* src;
	char* out;
	enum kind kind;
	struct dep* deplink;
};

struct dep { struct file* f; struct dep* nextdep; };

void readfile(struct file* f, char* src) {
	f->src = src;

	int fd = open(src, O_RDONLY);
	int sz = lseek(fd,0,SEEK_END); lseek(fd,0,SEEK_SET);
	char* file = mmap(0,sz,PROT_READ,MAP_PRIVATE,fd,0);
	close(fd);

	char namebuf[256];
	char* namecur = namebuf;
	char* cur = file;

	char strqt = 0;

read_start:
	if (*cur == 0) goto read_done;
	if (*cur == '"')  { ++ cur; strqt = '"';  goto read_string; }
	if (*cur == '\'') { ++ cur; strqt = '\''; goto read_string; }
	if (*cur == '(')  { ++ cur; strqt = ')';  goto read_string; }
	if (*cur == '[')  { ++ cur; strqt = ']';  goto read_string; }
	if (*cur == '/') {
		switch(cur[1]) {
			case '/': goto skip_line;
			case '*': cur += 2; goto read_ml_comment;
			case   0: goto read_done;
		}
		++cur; goto read_start;
	}
	if (*cur == '@') {
		if (strncmp(cur+1, "import", 6) == 0) {
			cur += 7; goto read_import;
		}
	}
	++cur; goto read_start;

read_import:
	if (*cur == ' ' || *cur == '\t' || *cur == '\n') {
		++cur; goto read_import;
	} else if (*cur == 'u' && cur[1] == 'r' && cur[2] == 'l') {
		strqt=')'; goto read_string;
	} else if (*cur == '"' || *cur=='\'') {
		strqt=*cur;
		while(*++cur != strqt) {
			if (*cur == '\\' && cur[1] == strqt) {
				*namecur++=strqt; cur += 2;
				// FIXME support other escapes
			} else {
				*namecur++=*cur;
			}
		}
		*namecur = 0;
		printf("found import to %s;\n", namebuf);
		namecur = namebuf;
	}
	++cur; goto read_start;

read_string:
	if (*cur == 0) goto read_done; //unterminated string!?
	if (*cur++ == strqt) goto read_start;
	goto read_string;

read_ml_comment:
	if (*cur == 0) goto read_done; //unterminated comment!
	if (*cur == '*' && cur[1] == '/') {
		cur += 2;
		goto read_start;
	}
	++cur; goto read_ml_comment;

skip_line:
	if (*cur == 0) goto read_done;
	if (*cur++ == '\n') goto read_start;
	goto skip_line;

read_done:

	munmap(file,sz);
}

enum e parsename(struct file* f) {
	char* ext = NULL;
	char* path = f->src;
	
	while(*path++!=0) {
		if(*path == '.') ext = path + 1;
	}

	
	if(ext == NULL) return badname;

	// quickly determine file type
	if        (ext[0] == 's'
			&& ext[2] == 's'
			&& ext[3] == 's') {
		if      (ext[1] == 'c') f -> kind = scss;
		else if (ext[1] == 'a') f -> kind = sass;
		else                    f -> kind = bad;
	} else if (ext[0] == 'c'
			&& ext[1] == 's'
			&& ext[2] == 's' )  f -> kind = css;
	else                        f -> kind = bad;

	if(f -> kind == sass || f -> kind == scss) {
		size_t sz = (ext - f->src);
		f->out = alloc(sz + 4);
		strncpy(f->out, f->src, sz);
		f->out[sz+0] = 'c';
		f->out[sz+1] = 's';
		f->out[sz+2] = 's';
		f->out[sz+3] = 0;
	} else f -> out = f -> src;

	printf("src %s; dst %s; ext %s;\n", f->src,f->out,ext);
}

int main(int argc, char** argv) {
	bufptr = corebuf;
	struct file top;
	readfile(&top, argv[1]);
	parsename(&top);
}

/* [ʞ] xpriv.c <c.hale.su/lexi/util>
 *  ~ lexi hale <lexi@hale.su>
 *  $ cc -Ofast xpriv.c -lrt -lutil -lX11 -oxpriv
 *  © affero general public license

 * xpriv.c is a tool for a very specific use case i have.
 * for security's  sake, i  don't tie my  ssh keys  to my
 * login session.  when i intend  to use them, i  spawn a
 * special terminal  and load the keys  into memory, then
 * exit that terminal when  i'm done using them. however,
 * i often lose  track of or accidentally  kill that win-
 * dow,  despite  adding  a  visual cue  to  its  prompt.
 * safekill.c was one half of  my attempt to address this
 * problem; this is the other.
 *
 * xpriv performs several different tasks to accomplish a
 * single  purpose: i  can  hit a  single keystroke  that
 * will either  conjure up  a new privileged  session, or
 * switch to one  that's already active if  it exists. it
 * does this  by first  checking for  the existence  of a
 * shared  memory  segment. if  it  doesn't  find it,  it
 * starts  a  new  session;  if it  *does*  find  it,  it
 * retrieves the  X11 window  ID from that  shared memory
 * and sends  a _NET_ACTIVE_WINDOW client message  to the
 * root X window. the  window manager interprets message,
 * activating the window.
 *
 * the  flag -k  can also  be passed,  in which  case the
 * utility instructs the running process to liquidate its
 * subprocesses and exit itself.
 *
 * if the shared  memory does not exist,  xpriv creates a
 * new instance  of urxvt. this  instance is told  to run
 * the command  “xpriv -a”  instead of the  user’s normal
 * shell. the -a flag instructs xpriv to get the terminal
 * window’s  ID from  the $WINDOWID  environment variable
 * which urxvt  sets. after this, a  ssh-agent process is
 * launched. spriv waits until it has opened a socket and
 * then runs ssh-add without parameters to add the user's
 * default keys to the session.
 *
 * xpriv  does  its  best   to  clean  up  after  itself,
 * killing all sensitive processes and their children and
 * removing the  shmem segment  when it  is no  longer in
 * use, even if exits somewhat abnormally. if you have to
 * kill -9 xpriv  at any point tho, you can  make it work
 * again (on linux) with
 *   rm /dev/shm/k.xpriv:(xpriv binary basename)
 *
 * you can have multiple xpriv sessions by creating soft-
 * links to the binary with a different name for each.

 TODO send signal to urxvtd directly instead of launching
      urxvtc as a separate process
	  
 TODO make shell & commands performed configurable, with
      flags to control or supplant ssh-agent 

 TODO add a randomizer call that works on BSD
 
 TODO document flags
 
 TODO implement/remove lock flag

 TODO add flag to bring window to current desktop */
 

#include <pwd.h>
#include <pty.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <X11/Xlib.h>
#include <errno.h>
#include <sys/random.h> //TODO bsd compat

#define shmem_prefix "/k.xpriv:"

typedef enum { false, true } bool;
enum mode { mode_usage, mode_go, mode_register,
	mode_kill, mode_lock };

enum res { ok, fail_parse, fail_arg, fail_opt, fail_shm,
               fail_mem, fail_pty, fail_nop, fail_win,
               fail_wid, fail_x11};
enum res bad(enum res code) {
	if (code == ok) return ok;

	write(1,"\e[1m|e|\e[0m ",12);
	const char* msg; uint8_t len;
	switch(code) {
		#define say(x) { msg = (x "\n"); len = (sizeof x) + 1; break; }
		case fail_parse: say("could not parse command-line options; pass -u for usage");
		case fail_arg  : say("invalid argument provided");
		case fail_opt  : say("no such option");
		case fail_shm  : say("instance already running");
		case fail_mem  : say("could not map memory");
		case fail_pty  : say("could not alloc pty");
		case fail_nop  : say("no instance running");
		case fail_win  : say("cannot open display");
		case fail_wid  : say("WINDOWID not defined");
		case fail_x11  : say("X server refuses to handle request");
		#undef say
	}
	write(1, msg, len);
	return code;
}

struct signal {
	Window    wid;
	pid_t     pid;
	pid_t     agent;
	enum mode op;
}*global;

char* itoa(unsigned long i, char* buf, size_t bufsz) {
	char* cur = buf + bufsz;
	while (cur >= buf) {
		*--cur='0' + i % 10;
		if (i < 10) break; else i /= 10;
	}
	return cur;
}

bool run;

struct termios initial_state;

void sigusr(int a) { if (global -> op == mode_kill) run = false; }
void sigterm(int a) { run = false; }

enum res register_window(const char* id, bool weak) {
	// the id field denotes the path to the shared memory
	// in use, and allows the user to have multiple
	// contexts by creating aliases to the binary
	int fd = shm_open(id, O_CREAT | O_EXCL | O_RDWR, 0600);
	ftruncate(fd, sizeof(struct signal));
	if (fd == -1) return fail_shm;
	
	struct signal* s = mmap(0, sizeof(struct signal),
			PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if(s == MAP_FAILED) return fail_mem;
	else global = s;

	Display* xdpy = XOpenDisplay(NULL);
	Atom xvital;

	/* x11 */ {
		if (xdpy == NULL) return fail_win;
		Window win;
		const char* winid_s;
		if (!(winid_s = getenv("WINDOWID"))) return fail_wid;
		win=(Window)strtol(winid_s,NULL,10);
		if(weak == false) xvital = XInternAtom(xdpy,"_k_vital",false);
		s -> wid = win;
	}

	pid_t child;
	if(child = fork()) {
		s -> pid = child;
		sigset_t mask, oldmask;
		sigemptyset(&mask);
		sigaddset(&mask, SIGUSR1);
		sigprocmask(SIG_BLOCK, &mask, &oldmask);

		signal(SIGUSR1, sigusr);
		signal(SIGTERM, sigterm);
		signal(SIGCHLD, sigterm);
		signal(SIGHUP, sigterm);

		run = true;
		while(run == true) {
			sigsuspend(&oldmask);
		}

		if(s -> op == mode_kill) {
			kill(s -> pid, SIGTERM);
		}
		kill(s -> agent, SIGTERM);
		sigprocmask(SIG_BLOCK, &mask, NULL);
		shm_unlink(id);
		if (!weak) {
			XDeleteProperty(xdpy,s -> wid,xvital);
			XSync(xdpy,false);
		}
		XCloseDisplay(xdpy);
	} else {
		// now we start ssh-agent and set the proper environment
		// variables
		pid_t ssha;

		/* messy part */ {
			const char* tmp; //tmpdir defined?
			if (!(tmp = getenv("TMPDIR"))) tmp = "/tmp";
			size_t tmpsz = strlen(tmp);
			
			char sockn[tmpsz + 1 + sizeof "ssh."
				+ 11];
			strcpy(sockn, tmp);
			sockn[tmpsz] = '/';
			strcpy(sockn+tmpsz+1,"ssh.");
			
			// first, gen a random identifier so we have the ability
			// to know where the socket winds up
			uint8_t* rndid = sockn+tmpsz+1+4;
			getrandom(rndid, 11, 0);
			
			// assuming ascii…
			for(uint8_t*i=rndid;i<rndid+11;++i) {
				*i = '0' + (*i % (25 * 2 + 10));
				if (*i > '9') *i += 7;
				if (*i > 'Z') *i += ('a' - 'Z');
			}

			if (ssha = fork()) {
				char pid_s_buf[16];
				char* pid_s = itoa(ssha, pid_s_buf, sizeof(pid_s_buf));
				while (access(sockn, F_OK));
					// avoid nasty race condition
				setenv("SSH_AGENT_PID", pid_s, true);
				setenv("SSH_AUTH_SOCK", sockn, true);
				s -> agent = ssha;
			} else {
				close(1); close(0);
				execlp("ssh-agent","ssh-agent","-D", "-a",sockn,0);
			}
		}
		
		pid_t sad;
		int p;
		if (sad = fork()) {
			int added;
			waitpid(sad, &added, 0);
			if (added == 0) {
				if (weak == false) {
					XChangeProperty(xdpy,s -> wid,xvital,xvital,8,PropModeReplace,"\01", 1);
					XSync(xdpy,false);
				}
				write(1,"\033c",3);
				execlp("fish","fish",NULL);
			} else { return ok; }
		} else {
			execlp("ssh-add","ssh-add",NULL);
		}
	}

	return ok; // this is kind of pointless but w/e
}
enum res kill_window(const char* id) {
	int fd = shm_open(id, O_RDWR, 0600);
	if (fd == -1) return fail_nop;

	struct signal* s = mmap(0, sizeof(struct signal),
			PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if(s == MAP_FAILED) return fail_mem;

	s -> op = mode_kill;
	kill(s -> pid, SIGUSR1);

	return ok;
}
enum res activate_window(Window w) {
	Display* dpy = XOpenDisplay(NULL);
	XEvent ev;
	long mask = SubstructureRedirectMask | SubstructureNotifyMask;
	ev.xclient.type       = ClientMessage;
	ev.xclient.serial     = 0;
	ev.xclient.send_event = True;
	ev.xclient.message_type = XInternAtom(dpy, "_NET_ACTIVE_WINDOW", False);
	ev.xclient.display    = dpy;
	ev.xclient.window     = w;
	ev.xclient.format     = 32;
	ev.xclient.data.l[0]  = 2;
	ev.xclient.data.l[1]  = CurrentTime;
	ev.xclient.data.l[2]  = 0;
	
	if(!XSendEvent(dpy, DefaultRootWindow(dpy), False, mask, &ev)) return fail_x11;

	XSync(dpy,false);
	return ok;
}

int main(int sz, char** argv) {
	enum mode op = mode_go;
	bool init_weak = false;

	for(int i = 1; i<sz; ++i) {
		char* v = argv[i];
		if (*v != '-') return bad(fail_arg);
		char* opt = v + 1;
	read_opt:
		switch(*opt) {
			case 'a': op = mode_register; break;
			case 'k': op = mode_kill; break;
			case 'l': op = mode_lock; break;
			case 'h': op = mode_usage; break;
			case 'w': init_weak = true; break;
			default: return bad(fail_opt);
		}
		if(opt[1] != 0) { ++opt; goto read_opt; }
	}

	size_t nsz;
	const char* basename, *p;
	for (p = argv[0]; *p!=0; ++p) {
		if(*p == '/') basename = p + 1;
	}
	nsz = p - basename;
	char shid[nsz + sizeof shmem_prefix + 0];
	strncpy(shid,shmem_prefix,sizeof shmem_prefix);
	strncpy(shid + sizeof shmem_prefix - 1, basename, nsz);

	if (op == mode_go) {
		int fd;
		if ((fd = shm_open(shid, O_RDWR, 0600)) == -1) {
			execlp("urxvtc", "urxvtc", "-bg", "[80]#4b0024",
					"-e", argv[0], (init_weak?"-aw":"-a"), 0);
		} else {
			struct signal*s = mmap(0, sizeof(struct signal),
					PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
			return bad(activate_window(s->wid));
		}
	} else if (op == mode_register)
		return bad(register_window(shid,init_weak));
	else if (op == mode_kill)
		return bad(kill_window(shid));
	else if (op == mode_usage) {
		write(1,"\e[1musage:\e[0m ",15);
		write(1, argv[0], strlen(argv[0]));
		write(1, " [-aklw [arg]]\n",16);
		return fail_parse;
	}
}