Merge a number of fixes for CentOS 7

Webdis needed a number of small fixes to build and run on CentOS 7
(released in 2014). Initially reported in PR #231 as a missing -std=
compiler flag, there turned out to be more tweaks needed to cleanly
build and run.

Makefile

@@ -5,7 +5,7 @@ B64_OBJS?=src/b64/cencode.o
 FORMAT_OBJS?=src/formats/json.o src/formats/raw.o src/formats/common.o src/formats/custom-type.o
 HTTP_PARSER_OBJS?=src/http-parser/http_parser.o
 
-CFLAGS ?= -Wall -Wextra -Isrc -Isrc/jansson/src -Isrc/http-parser -MD
+CFLAGS ?= -std=c99 -Wall -Wextra -Isrc -Isrc/jansson/src -Isrc/http-parser -MD -D_POSIX_C_SOURCE=200809L -Wno-pragmas
 LDFLAGS ?= -levent -pthread
 
 # Pass preprocessor macros to the compile invocation

src/acl.c

@@ -5,6 +5,7 @@
 #include "client.h"
 
 #include <string.h>
+#include <strings.h>
 #include <evhttp.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>

src/client.c

@@ -9,6 +9,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 #include <unistd.h>
 #include <errno.h>
 #include <hiredis/hiredis.h>

src/cmd.c

@@ -16,6 +16,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 #include <hiredis/hiredis.h>
 #include <hiredis/async.h>
 #include <ctype.h>

src/conf.c

@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
 #include <ctype.h>
 #include <arpa/inet.h>
 #include <unistd.h>

src/formats/json.c

@@ -5,6 +5,7 @@
 #include "client.h"
 
 #include <string.h>
+#include <strings.h>
 #include <hiredis/hiredis.h>
 #include <hiredis/async.h>
 

src/formats/msgpack.c

@@ -5,6 +5,7 @@
 #include "client.h"
 
 #include <string.h>
+#include <strings.h>
 #include <hiredis/hiredis.h>
 #include <hiredis/async.h>
 

src/hiredis/fmacros.h

@@ -2,7 +2,9 @@
 #define __HIREDIS_FMACRO_H
 
 #define _XOPEN_SOURCE 600
+#ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200112L
+#endif
 
 #if defined(__APPLE__) && defined(__MACH__)
 /* Enable TCP_KEEPALIVE */

src/http.c

@@ -5,6 +5,7 @@
 #include "slog.h"
 
 #include <string.h>
+#include <strings.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>

src/server.c

@@ -200,7 +200,7 @@ server_daemonize(struct server *s, const char *pidfile) {
 
 	/* write pidfile */
 	if(pidfile) {
-		int pid_fd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW, 0600);
+		int pid_fd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 		if(pid_fd > 0) {
 			char pid_buffer[(CHAR_BIT * sizeof(int) / 3) + 3]; /* max length for int */
 			int pid_sz = snprintf(pid_buffer, sizeof(pid_buffer), "%d\n", (int)getpid());