From: Denis Ovsienko <denis@ovsienko.info>
Date: Mon, 25 Mar 2024 15:02:50 +0000 (+0000)
Subject: Disregard setlinebuf(3), always use setvbuf(3).
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/a9c7cf884805b0a3ebdefd574e5a061f31c5e3fb

Disregard setlinebuf(3), always use setvbuf(3).

As most setlinebuf(3) man pages mention, setlinebuf() is a shorthand for
setvbuf().  The latter is in C99, but the former is not, so it is most
logical to use setvbuf() in all cases and to lose another build-time
check.
---

diff --git a/CHANGES b/CHANGES
index d8200348..f856b64d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -42,6 +42,7 @@ DayOfTheWeek, Month DD, YYYY / The Tcpdump Group
       IEEE 802.11: Simplify handle_action().
       Provide GET_ macros for 4-byte and 8-byte floating-point numbers
         and use them rather than custom code
+      Disregard setlinebuf(3), always use setvbuf(3).
     Building and testing:
       autoconf: Update install-sh script to the latest available version.
       autoconf: Remove detection of early IPv6 stacks.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a3c44b41..d38e4b3b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -485,7 +485,6 @@ tcpdump would not work correctly even if it managed to compile."
 endif()
 
 check_function_exists(getopt_long HAVE_GETOPT_LONG)
-check_function_exists(setlinebuf HAVE_SETLINEBUF)
 #
 # For Windows,  don't need to waste time checking for fork() or vfork().
 #
diff --git a/cmakeconfig.h.in b/cmakeconfig.h.in
index fc2dd137..52794e5d 100644
--- a/cmakeconfig.h.in
+++ b/cmakeconfig.h.in
@@ -162,9 +162,6 @@
 /* Define to 1 if you have the <rpc/rpc.h> header file. */
 #cmakedefine HAVE_RPC_RPC_H 1
 
-/* Define to 1 if you have the `setlinebuf' function. */
-#cmakedefine HAVE_SETLINEBUF 1
-
 /* Define to 1 if you have the <stdint.h> header file. */
 #cmakedefine HAVE_STDINT_H 1
 
diff --git a/configure.ac b/configure.ac
index 77ad065c..78c9b1be 100644
--- a/configure.ac
+++ b/configure.ac
@@ -283,7 +283,6 @@ AC_LBL_LIBRARY_NET
 
 AC_REPLACE_FUNCS(strlcat strlcpy strsep getservent getopt_long)
 AC_CHECK_FUNCS(fork vfork)
-AC_CHECK_FUNCS(setlinebuf)
 
 #
 # Make sure we have snprintf(); we require it.
diff --git a/tcpdump.c b/tcpdump.c
index 28f68077..0e6fd3ba 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -1781,11 +1781,7 @@ main(int argc, char **argv)
 			 */
 			setvbuf(stdout, NULL, _IONBF, 0);
 #else /* _WIN32 */
-#ifdef HAVE_SETLINEBUF
-			setlinebuf(stdout);
-#else
 			setvbuf(stdout, NULL, _IOLBF, 0);
-#endif
 #endif /* _WIN32 */
 			lflag = 1;
 			break;