getprogname() and setproctitle() on Linux.

Makefile.am

@@ -26,7 +26,7 @@ if IS_GCC
 CFLAGS += -std=gnu99 -O2
 if IS_DEBUG
 CFLAGS += -g
-CFLAGS += -Wno-long-long -Wall -W -Wnested-externs -Wformat=2
+CFLAGS += -Wno-long-long -Wall -W -Wformat=2
 CFLAGS += -Wmissing-prototypes -Wstrict-prototypes -Wmissing-declarations
 CFLAGS += -Wwrite-strings -Wshadow -Wpointer-arith -Wsign-compare
 CFLAGS += -Wundef -Wbad-function-cast -Winline -Wcast-align
@@ -194,6 +194,15 @@ endif
 if NO_DAEMON
 nodist_tmux_SOURCES += compat/daemon.c
 endif
+if NO_DAEMON
+nodist_tmux_SOURCES += compat/daemon.c
+endif
+if NO_GETPROGNAME
+nodist_tmux_SOURCES += compat/getprogname.c
+endif
+if NO_SETPROCTITLE
+nodist_tmux_SOURCES += compat/setproctitle.c
+endif
 if NO_SETENV
 nodist_tmux_SOURCES += compat/setenv.c
 endif

compat.h

@@ -223,6 +223,16 @@ size_t	 	 strlcat(char *, const char *, size_t);
 int	 	 daemon(int, int);
 #endif
 
+#ifndef HAVE_GETPROGNAME
+/* getprogname.c */
+const char	*getprogname(void);
+#endif
+
+#ifndef HAVE_SETPROCTITLE
+/* setproctitle.c */
+void		 setproctitle(const char *, ...);
+#endif
+
 #ifndef HAVE_B64_NTOP
 /* b64_ntop.c */
 #undef b64_ntop /* for Cygwin */

compat/getprogname.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2016 Nicholas Marriott <nicholas.marriott@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include "tmux.h"
+
+#if defined(HAVE_PROGRAM_INVOCATION_SHORT_NAME)
+const char *
+getprogname(void)
+{
+	extern char	*program_invocation_short_name;
+
+	return (program_invocation_short_name);
+}
+#elif defined(HAVE___PROGNAME)
+const char *
+getprogname(void)
+{
+	extern char	*__progname;
+
+	return (__progname);
+}
+#else
+const char *
+getprogname(void)
+{
+	return ("tmux");
+}
+#endif

compat/setproctitle.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016 Nicholas Marriott <nicholas.marriott@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <string.h>
+
+#include "tmux.h"
+
+#if defined(HAVE_PRCTL) && defined(HAVE_PR_SET_NAME)
+
+#include <sys/prctl.h>
+
+void
+setproctitle(const char *fmt, ...)
+{
+	char	title[16], name[16], *cp;
+	va_list	ap;
+	int	used;
+
+	va_start(ap, fmt);
+	vsnprintf(title, sizeof title, fmt, ap);
+	va_end(ap);
+
+	used = snprintf(name, sizeof name, "%s: %s", getprogname(), title);
+	if (used >= (int)sizeof name) {
+		cp = strrchr(name, ' ');
+		if (cp != NULL)
+			*cp = '\0';
+	}
+	prctl(PR_SET_NAME, name);
+}
+#else
+void
+setproctitle(const char *fmt, ...)
+{
+}
+#endif

configure.ac

@@ -113,7 +113,7 @@ AC_CHECK_FUNCS(
 	[ \
 		dirfd \
 		flock \
-		setproctitle \
+		prctl \
 		sysconf \
 		cfmakeraw \
 	]
@@ -298,6 +298,20 @@ if test "x$found_daemon" = xyes; then
 fi
 AM_CONDITIONAL(NO_DAEMON, [test "x$found_daemon" = xno])
 
+# Look for getprogname, compat/getprogname.c used if missing.
+AC_CHECK_FUNC(getprogname, found_getprogname=yes, found_getprogname=no)
+if test "x$found_getprogname" = xyes; then
+	AC_DEFINE(HAVE_GETPROGNAME)
+fi
+AM_CONDITIONAL(NO_GETPROGNAME, [test "x$found_getprogname" = xno])
+
+# Look for setproctitle, compat/setproctitle.c used if missing.
+AC_CHECK_FUNC(setproctitle, found_setproctitle=yes, found_setproctitle=no)
+if test "x$found_setproctitle" = xyes; then
+	AC_DEFINE(HAVE_SETPROCTITLE)
+fi
+AM_CONDITIONAL(NO_SETPROCTITLE, [test "x$found_setproctitle" = xno])
+
 # Look for setenv, compat/setenv.c used if missing.
 AC_CHECK_FUNC(setenv, found_setenv=yes, found_setenv=no)
 if test "x$found_setenv" = xyes; then
@@ -475,6 +489,31 @@ AC_LINK_IFELSE([AC_LANG_SOURCE(
 	AC_MSG_RESULT(no)
 )
 
+# Look for program_invocation_short_name.
+AC_MSG_CHECKING(for program_invocation_short_name)
+AC_LINK_IFELSE([AC_LANG_SOURCE(
+	[
+		#include <stdio.h>
+		#include <stdlib.h>
+		extern char *program_invocation_short_name;
+		int main(void) {
+			const char *cp = program_invocation_short_name;
+			printf("%s\n", cp);
+			exit(0);
+		}
+	])],
+	[AC_DEFINE(HAVE_PROGRAM_INVOCATION_SHORT_NAME) AC_MSG_RESULT(yes)],
+	AC_MSG_RESULT(no)
+)
+
+# Look for prctl(PR_SET_NAME).
+AC_CHECK_DECL(
+	PR_SET_NAME,
+	AC_DEFINE(HAVE_PR_SET_NAME),
+	,
+	[#include <sys/prctl.h>]
+)
+
 # Look for fcntl(F_CLOSEM).
 AC_CHECK_DECL(
 	F_CLOSEM,

proc.c

@@ -191,9 +191,7 @@ proc_start(const char *name, struct event_base *base, int forkflag,
 
 	log_open(name);
 
-#ifdef HAVE_SETPROCTITLE
 	setproctitle("%s (%s)", name, socket_path);
-#endif
 
 	if (uname(&u) < 0)
 		memset(&u, 0, sizeof u);