Bell 32V development

Work on file usr/src/libc/gen/ttyslot.c

Co-Authored-By: John Reiser <jfr@research.uucp>
Synthesized-from: 32v

diff --git a/usr/src/libc/gen/ttyslot.c b/usr/src/libc/gen/ttyslot.c
new file mode 100755 (executable)
index 0000000..6449aab
--- /dev/null
+++ b/usr/src/libc/gen/ttyslot.c
@@ -0,0 +1,58 @@
+/*
+ * Return the number of the slot in the utmp file
+ * corresponding to the current user: try for file 0, 1, 2.
+ * Definition is the line number in the /etc/ttys file.
+ */
+
+
+char   *ttyname();
+char   *getttys();
+char   *rindex();
+static char    ttys[]  = "/etc/ttys";
+
+#define        NULL    0
+
+ttyslot()
+{
+       register char *tp, *p;
+       register s, tf;
+
+       if ((tp=ttyname(0))==NULL && (tp=ttyname(1))==NULL && (tp=ttyname(2))==NULL)
+               return(0);
+       if ((p = rindex(tp, '/')) == NULL)
+               p = tp;
+       else
+               p++;
+       if ((tf=open(ttys, 0)) < 0)
+               return(0);
+       s = 0;
+       while (tp = getttys(tf)) {
+               s++;
+               if (strcmp(p, tp)==0) {
+                       close(tf);
+                       return(s);
+               }
+       }
+       close(tf);
+       return(0);
+}
+
+static char *
+getttys(f)
+{
+       static char line[32];
+       register char *lp;
+
+       lp = line;
+       for (;;) {
+               if (read(f, lp, 1) != 1)
+                       return(NULL);
+               if (*lp =='\n') {
+                       *lp = '\0';
+                       return(line+2);
+               }
+               if (lp >= &line[32])
+                       return(line+2);
+               lp++;
+       }
+}