shm_open.3: Use sizeof consistently

Use ``sizeof`` consistently through all the examples in the following
way:

- Use the name of the variable instead of its type as argument for
  ``sizeof``.

	Rationale:
	https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man3/shm_open.3 b/man3/shm_open.3
index bba4eb8266394b39442fa270febd4ea2c514054d..24cc6a40320c180de6298620f5e66b6319bb5e4f 100644 (file)
--- a/man3/shm_open.3
+++ b/man3/shm_open.3
@@ -382,7 +382,7 @@ main(int argc, char *argv[])
 
     /* Map the object into the caller\(aqs address space */
 
-    struct shmbuf *shmp = mmap(NULL, sizeof(struct shmbuf),
+    struct shmbuf *shmp = mmap(NULL, sizeof(*shmp),
                                PROT_READ | PROT_WRITE,
                                MAP_SHARED, fd, 0);
     if (shmp == MAP_FAILED)
@@ -471,7 +471,7 @@ main(int argc, char *argv[])
     if (fd == \-1)
         errExit("shm_open");
 
-    struct shmbuf *shmp = mmap(NULL, sizeof(struct shmbuf),
+    struct shmbuf *shmp = mmap(NULL, sizeof(*shmp),
                                PROT_READ | PROT_WRITE,
                                MAP_SHARED, fd, 0);
     if (shmp == MAP_FAILED)