Add the -p flag to force unknown control sequences to be passed

through unchanged.

Reviewed by:	silence on -audit
Obtained from:	NetBSD
MFC after:	3 weeks

usr.bin/col/README

@@ -1,4 +1,6 @@
 #	@(#)README	8.1 (Berkeley) 6/6/93
+#
+# $FreeBSD$
 
 col - filter out reverse line feeds.
 
@@ -6,6 +8,7 @@ Options are:
 	-b	do not print any backspaces (last character written is printed)
 	-f	allow half line feeds in output, by default characters between
 		lines are pushed to the line below
+	-p	force unknown control sequences to be passed through unchanged
 	-x	do not compress spaces into tabs.
 	-l num	keep (at least) num lines in memory, 128 are kept by default
 
@@ -20,9 +23,6 @@ page to reflect the way the code worked.  Suspecting that this was probably
 the wrong way to go, this version adopts the SVID defaults, and no longer
 documents the -h option.
 
-The S5 -p flag is not supported because it isn't clear what it does (looks
-like a kludge introduced for a particular printer).
-
 Known differences between AT&T's col and this one (# is delimiter):
 	Input			AT&T col		this col
 	#\nabc\E7def\n#		#   def\nabc\r#		#   def\nabc\n#

usr.bin/col/col.1

@@ -43,7 +43,7 @@
 .Nd filter reverse line feeds from input
 .Sh SYNOPSIS
 .Nm
-.Op Fl bfhx
+.Op Fl bfhpx
 .Op Fl l Ar num
 .Sh DESCRIPTION
 .Nm Col
@@ -69,6 +69,12 @@ Normally characters printed on a half line boundary are printed
 on the following line.
 .It Fl h
 Don't output multiple spaces instead of tabs (default).
+.It Fl p
+Force unknown control sequences to be passed through unchanged.
+Normally,
+.Nm
+will filter out any control sequences from the input other than those
+recognized and interpreted by itself, which are listed below.
 .It Fl x
 Output multiple spaces instead of tabs.
 .It Fl l Ar num

usr.bin/col/col.c

@@ -110,6 +110,7 @@ int	fine;			/* if `fine' resolution (half lines) */
 int	max_bufd_lines;		/* max # lines to keep in memory */
 int	nblank_lines;		/* # blanks after last flushed line */
 int	no_backspaces;		/* if not to output any backspaces */
+int	pass_unknown_seqs;	/* pass unknown control sequences */
 
 #define	PUTC(ch) \
 	do {					\
@@ -138,7 +139,7 @@ main(argc, argv)
 
 	max_bufd_lines = 128;
 	compress_spaces = 1;		/* compress spaces into tabs */
-	while ((opt = getopt(argc, argv, "bfhl:x")) != -1)
+	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
 		switch (opt) {
 		case 'b':		/* do not output backspaces */
 			no_backspaces = 1;
@@ -153,6 +154,9 @@ main(argc, argv)
 			if ((max_bufd_lines = atoi(optarg)) <= 0)
 				errx(1, "bad -l argument %s", optarg);
 			break;
+		case 'p':		/* pass unknown control sequences */
+			pass_unknown_seqs = 1;
+			break;
 		case 'x':		/* do not compress spaces into tabs */
 			compress_spaces = 0;
 			break;
@@ -220,7 +224,8 @@ main(argc, argv)
 				cur_line -= 2;
 				continue;
 			}
-			continue;
+			if (!pass_unknown_seqs)
+				continue;
 		}
 
 		/* Must stuff ch in a line - are we at the right one? */
@@ -530,7 +535,7 @@ void
 usage()
 {
 
-	(void)fprintf(stderr, "usage: col [-bfhx] [-l nline]\n");
+	(void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
 	exit(1);
 }