From 0b4c2ceb2f4594cc9d5ca09e39fb57f6e4f82bfb Mon Sep 17 00:00:00 2001
From: Heiko Berges <hbs-bierbaum@t-online.de>
Date: Thu, 21 Sep 2023 14:56:58 +0200
Subject: [PATCH] ed: Add support for ! in w command

When the file name begins with ! then the addressed buffer content is
piped to the name of the file that is considered a command that is
executed in a shell.
---
 ed.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/ed.c b/ed.c
index b661ac5..e6ca22b 100644
--- a/ed.c
+++ b/ed.c
@@ -626,8 +626,14 @@ dowrite(const char *fname, int trunc)
 	size_t bytecount = 0;
 	int i, line;
 
-	if (!(fp = fopen(fname, (trunc) ? "w" : "a")))
-		error("input/output error");
+	if(fname[0] == '!') {
+		fname++;
+		if((fp = popen(fname, "r")) == NULL)
+			error("Bad Exec");
+	} else {
+		if ((fp = fopen(fname, "r")) == NULL)
+			error("cannot open input file");
+	}
 
 	line = curln;
 	for (i = line1; i <= line2; ++i) {