54494: Add zsocket -s to shutdown() a socket fd

3 files changed, 21 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 4d6130ba9..10001b2ab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -23,6 +23,9 @@
 	* 54493: Src/Modules/socket.c: socket: fix some issues with
 	socket name
 
+	* 54494: Doc/Zsh/mod_socket.yo, Src/Modules/socket.c: Add zsocket
+	-s to shutdown() a socket fd
+
 2026-05-10  Oliver Kiddle  <opk@zsh.org>
 
 	* unposted: Completion/Linux/Command/_selinux: complete files
diff --git a/Doc/Zsh/mod_socket.yo b/Doc/Zsh/mod_socket.yo
index 78d9254e8..2c699b1d1 100644
--- a/Doc/Zsh/mod_socket.yo
+++ b/Doc/Zsh/mod_socket.yo
@@ -7,7 +7,7 @@ startitem()
 findex(zsocket)
 cindex(sockets)
 cindex(sockets, Unix domain)
-item(tt(zsocket) [ tt(-altv) ] [ tt(-d) var(fd) ] [ var(args) ])(
+item(tt(zsocket) [ tt(-alstv) ] [ tt(-d) var(fd) ] [ var(args) ])(
 tt(zsocket) is implemented as a builtin to allow full use of shell
 command line editing, file I/O, and job control mechanisms.
 )
@@ -33,6 +33,11 @@ File descriptors can be closed with normal shell syntax when no longer
 needed, for example:
 
 example(exec {REPLY}>&-)
+
+The tt(zsocket -s var(fd)) command may also be used to shut down a
+socket fd before closing it. This will send an EOF to the other side,
+while this side can still read their subsequent response before closing
+the connection fully, for example.
 )
 enditem()
 
diff --git a/Src/Modules/socket.c b/Src/Modules/socket.c
index 4f2a6ecbf..2c8a48c28 100644
--- a/Src/Modules/socket.c
+++ b/Src/Modules/socket.c
@@ -229,6 +229,17 @@ bin_zsocket(char *nam, char **args, Options ops, UNUSED(int func))
 	if (verbose)
 	    printf("new connection from %s is on fd %d\n", soun.sun_path, sfd);
     }
+    else if (OPT_ISSET(ops,'s'))
+    {
+	if (!args[0]) {
+	    zwarnnam(nam, "-s requires an argument");
+	    return 1;
+	}
+
+	int err = shutdown(atoi(args[0]), SHUT_WR);
+	if (err)
+	    zwarn("shutdown failed: %e", errno);
+    }
     else
     {
 	if (!args[0]) {
@@ -282,7 +293,7 @@ bin_zsocket(char *nam, char **args, Options ops, UNUSED(int func))
 }
 
 static struct builtin bintab[] = {
-    BUILTIN("zsocket", 0, bin_zsocket, 0, 3, 0, "ad:ltv", NULL),
+    BUILTIN("zsocket", 0, bin_zsocket, 0, 3, 0, "ad:lstv", NULL),
 };
 
 static struct features module_features = {