New compilation variable WITHOUT_SHM, to disable shared memory functions.

2 files changed, 29 insertions, 0 deletions

diff --git a/README.md b/README.md
index 1e5c2e8..6c1e31b 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,12 @@ If your compilation process complains about undefined references to `shm_open()`
 make LDFLAGS=-lrt
 ```
 
+If it still doesn't work (because your system does not implement the shared memory functions) or you are just not interested, you can compile out with
+
+```sh
+make CFLAGS=-DWITHOUT_SHM
+```
+
 See the administrator manual on how to proceed from here.
 
 ## Testing via Docker
diff --git a/httpd.c b/httpd.c
index d63fa0f..993aa1c 100644
--- a/httpd.c
+++ b/httpd.c
@@ -653,6 +653,29 @@ void term_handler(int s)
 }
 
 
+#ifdef WITHOUT_SHM
+
+/* dummy versions */
+
+int shm_open(const char *name, int flags, mode_t mode)
+{
+    (void)name;
+    (void)flags;
+    (void)mode;
+
+    errno = ENOTSUP;
+    return -1;
+}
+
+int shm_unlink(const char *name)
+{
+    (void)name;
+    return -1;
+}
+
+
+#endif
+
 srv_state *srv_state_op(xs_str **fname, int op)
 /* opens or deletes the shared memory object */
 {