1 files changed, 28 insertions, 0 deletions
diff --git a/sys/fmtio/fmtsetcol.x b/sys/fmtio/fmtsetcol.x
new file mode 100644
index 00000000..a8d06855
--- /dev/null
+++ b/sys/fmtio/fmtsetcol.x
@@ -0,0 +1,28 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<ctype.h>
+include	<printf.h>
+
+# FMT_SETCOL -- Called when a control character is output, to keep track of
+# the column index during output, for the "%nt" (tabulate) format.  Columns
+# are indexed from the start of the printf, rather than in absolute units on
+# the output, unless a \r or \n is output during the print.
+
+procedure fmt_setcol (ch, col)
+
+char	ch
+int	col
+
+begin
+	switch (ch) {
+	case '\t':					# next tab stop
+	    col = ((col + TABSTOP-1) / TABSTOP) * TABSTOP + 1
+	case '\n', '\r', '\f':
+	    col = 1
+	case '\b':
+	    col = col - 1
+	default:
+	    if (IS_PRINT (ch))
+		col = col + 1
+	}
+end