[9fans] focus window on plumb

[umbraticus]

Hi 9fans,

I wrote the attached to listen on a plumb port and make
a given window current when it gets a message.  I'm not
sure how much I will like it: it's nice not to have to
hunt for a buried client program after plumbing something;
on the other hand, sometimes I like to plumb a few urls,
images, or pdfs and view later.  Still, I thought I'd
figure out a way to do it.

The first argument is the port to listen on and the second
is a string to match against the label of the window to
raise.  In my riostart I start my main rc window like this:

window 'raiseplumb web mothra! & raiseplumb edit sam & raiseplumb image page & 
cat todo; label rc; rc'

(After setting page's label I bind /dev/null over it so it
isn't overwritten) The program could be improved but it
seems to work well enough for a quick implementation.

Other solutions I thought of were to prime the windows I
want to raise by posting their wctl in /srv (since /dev/wsys
isn't in the plumber's namespace) then writing plumb rules
to first raise the window by mounting the wctl, then plumb
to the port; or else patch the client programs to raise
themselves when they get a plumb.

Has anyone else wanted/implemented something like this?

umbraticus
#include <u.h>
#include <libc.h>
#include <plumb.h>

enum{LEN = 128};

int
match(int n, char *label)
{
        int fd, len;
        char s[LEN];

        snprint(s, LEN, "/dev/wsys/%d/label", n);
        if((fd = open(s, OREAD)) < 0)
                return 0;
        len = strlen(label);
        if(read(fd, s, len) != len || memcmp(s, label, len) != 0){
                close(fd);
                return 0;
        }
        close(fd);
        snprint(s, LEN, "/dev/wsys/%d/wctl", n);
        if((fd = open(s, OWRITE)) < 0)
                return -1;
        fprint(fd, "unhide");
        fprint(fd, "current");
        close(fd);
        return 1;
}

void
findwctl(char *label)
{
        Dir *d;
        int fd, n, i;

        if((fd = open("/dev/wsys", OREAD)) < 0)
                return;
        while((n = dirread(fd, &d)) > 0){
                for(i = 0; i < n; i++)
                        if(match(atoi(d[i].name), label)){
                                free(d);
                                close(fd);
                                return;
                        }
                free(d);
        }
        close(fd);
}

void
main(int argc, char **argv)
{
        Plumbmsg *m;
        int fd;

        if(argc != 3)
                sysfatal("usage: %s fd label", argv[0]);
        if(strlen(argv[2]) >= LEN)
                sysfatal("label match too long: %s", argv[2]);
        if((fd = plumbopen(argv[1], OREAD)) < 0)
                sysfatal("couldn't open plumb fd %s", argv[1]);
        for(;;){
                if((m = plumbrecv(fd)) == nil)
                        sysfatal("error on plumb fd %s", argv[1]);
                plumbfree(m);
                findwctl(argv[2]);
        }
}