new program acmeevent

Reference: /n/atom/patch/applied/acmeevent
Date: Fri Feb 28 12:31:11 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/acmeevent.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/cmd/acmeevent.c	Fri Feb 28 12:31:07 2014
@@ -0,0 +1,92 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+
+int
+getn(Biobuf *b)
+{
+	int c, n;
+
+	n = 0;
+	while((c = Bgetc(b)) != -1 && '0'<=c && c<='9')
+		n = n*10+c-'0';
+	if(c != ' ')
+		sysfatal("bad number syntax");
+	return n;
+}
+
+char*
+getrune(Biobuf *b, char *p)
+{
+	int c;
+	char *q;
+
+	c = Bgetc(b);
+	if(c == -1)
+		sysfatal("eof");
+	q = p;
+	*q++ = c;
+	if(c >= Runeself){
+		while(!fullrune(p, q-p)){
+			c = Bgetc(b);
+			if(c == -1)
+				sysfatal("eof");
+			*q++ = c;
+		}
+	}
+	return q;
+}
+
+void
+getevent(Biobuf *b, int *c1, int *c2, int *q0, int *q1, int *flag, int *nr, char *buf)
+{
+	int i;
+	char *p;
+
+	*c1 = Bgetc(b);
+	if(*c1 == -1)
+		exits(0);
+	*c2 = Bgetc(b);
+	*q0 = getn(b);
+	*q1 = getn(b);
+	*flag = getn(b);
+	*nr = getn(b);
+	if(*nr >= 256)
+		sysfatal("event string too long");
+	p = buf;
+	for(i=0; i<*nr; i++)
+		p = getrune(b, p);
+	*p = 0;
+	if(Bgetc(b) != '\n')
+		sysfatal("expected newline");
+}
+
+void
+main(void)
+{
+	int c1, c2, q0, q1, eq0, eq1, flag, nr, x;
+	Biobuf b;
+	char buf[2000], buf2[2000], buf3[2000];
+
+	doquote = needsrcquote;
+	quotefmtinstall();
+	Binit(&b, 0, OREAD);
+	for(;;){
+		getevent(&b, &c1, &c2, &q0, &q1, &flag, &nr, buf);
+		eq0 = q0;
+		eq1 = q1;
+		buf2[0] = 0;
+		buf3[0] = 0;
+		if(flag & 2){
+			/* null string with non-null expansion */
+			getevent(&b, &x, &x, &eq0, &eq1, &x, &nr, buf);
+		}
+		if(flag & 8){
+			/* chorded argument */
+			getevent(&b, &x, &x, &x, &x, &x, &x, buf2);
+			getevent(&b, &x, &x, &x, &x, &x, &x, buf3);
+		}
+		print("event %c %c %d %d %d %d %d %d %q %q %q\n",
+			c1, c2, q0, q1, eq0, eq1, flag, nr, buf, buf2, buf3);
+	}
+}