Add original unix v6

source/iolib/cputc.c

@@ -0,0 +1,30 @@
+# include "ciodec.c"
+char cputc(ch, fn)
+{
+struct fileps *fp;
+if (nargs() != 2)
+  IEHzap("cputc  ");
+if (fn<0 || fn>20) return(ch);
+fp = &IEH3fpts[fn];
+if (fp->wrflag == 1)
+	IEH3err("cputc: %d not open",fn);
+if (fp->wrflag == 0)
+	IEH3mbuf(fn,1);
+*(fp->bptr++) = ch;
+if (++(fp->nchars) < fp->bsize)
+	return(ch);
+if (fp->wrflag == 3) /* append, seek to end */
+	{
+	seek(fn, 0, 2);
+	fp->wrflag = 2; /* now just write from here on */
+	}
+if ( write(fn, fp->bptr=fp->buff, fp->nchars) < 0)
+	{
+	if (fp->eoferr == 0)
+		IEH3err("cputc: writing %d",fn);
+	fp->eoferr = 3;
+	}
+fp->nchars = 0;
+return (ch);
+}
+cout 1;