1 files changed, 31 insertions, 0 deletions
diff --git a/unix/boot/spp/rpp/rpprat/dosub.r b/unix/boot/spp/rpp/rpprat/dosub.r
new file mode 100644
index 00000000..611bdbaf
--- /dev/null
+++ b/unix/boot/spp/rpp/rpprat/dosub.r
@@ -0,0 +1,31 @@
+#-h-  dosub			  709  local   12/01/80  15:53:50
+# dosub - select macro substring
+   include  defs
+
+   subroutine dosub (argstk, i, j)
+   integer argstk (ARGSIZE), i, j
+
+   include COMMON_BLOCKS
+
+   integer ap, fc, k, nc
+   integer ctoi, length
+
+   if (j - i < 3)
+      return
+   if (j - i < 4)
+      nc = MAXTOK
+   else {
+      k = argstk (i + 4)
+      nc = ctoi (evalst, k)	 # number of characters
+      }
+   k = argstk (i + 3)	      # origin
+   ap = argstk (i + 2)	       # target string
+   fc = ap + ctoi (evalst, k) - 1   # first char of substring
+   if (fc >= ap & fc < ap + length (evalst (ap))) {   # subarrays
+      k = fc + min (nc, length (evalst (fc))) - 1
+       for ( ; k >= fc; k = k - 1)
+	  call putbak (evalst (k))
+       }
+
+    return
+    end