Add dtach -N.

dtach -N is similar to dtach -n, except dtach will not daemonize.

Based on patches by Ciprian Dorin Craciun and Frank Hunleth.

dtach.1

@@ -13,6 +13,9 @@ dtach \- simple program that emulates the detach feature of screen.
 .br
 .B dtach \-n
 .I <socket> <options> <command...>
+.br
+.B dtach \-N
+.I <socket> <options> <command...>
 
 .SH DESCRIPTION
 .B dtach
@@ -93,6 +96,13 @@ which the specified program is executed.
 .B dtach
 does not try to attach to the newly created session, however, and exits
 instead.
+.TP
+.B \-N
+Creates a new session, without attaching to it or daemonizing. A new session is
+created in which the specified program is executed.
+.B dtach
+does not try to attach to the newly created session, however, and will stay
+in the foreground until the program exits.
 
 .PP
 .SS OPTIONS

dtach.h

@@ -128,7 +128,7 @@ struct packet
 #define EOS "\033[999H"
 
 int attach_main(int noerror);
-int master_main(char **argv, int waitattach);
+int master_main(char **argv, int waitattach, int dontfork);
 
 #ifdef sun
 #define BROKEN_MASTER

main.c

@@ -55,6 +55,7 @@ usage()
 		"       dtach -A <socket> <options> <command...>\n"
 		"       dtach -c <socket> <options> <command...>\n"
 		"       dtach -n <socket> <options> <command...>\n"
+		"       dtach -N <socket> <options> <command...>\n"
 		"Modes:\n"
 		"  -a\t\tAttach to the specified socket.\n"
 		"  -A\t\tAttach to the specified socket, or create it if it\n"
@@ -62,6 +63,9 @@ usage()
 		"  -c\t\tCreate a new socket and run the specified command.\n"
 		"  -n\t\tCreate a new socket and run the specified command "
 		"detached.\n"
+		"  -N\t\tCreate a new socket and run the specified command "
+		"detached,\n"
+		"\t\t  and have dtach run in the foreground.\n"
 		"Options:\n"
 		"  -e <char>\tSet the detach character to <char>, defaults "
 		"to ^\\.\n"
@@ -102,7 +106,7 @@ main(int argc, char **argv)
 		if (mode == '?')
 			usage();
 		else if (mode != 'a' && mode != 'c' && mode != 'n' &&
-			 mode != 'A')
+			 mode != 'A' && mode != 'N')
 		{
 			printf("%s: Invalid mode '-%c'\n", progname, mode);
 			printf("Try '%s --help' for more information.\n",
@@ -215,7 +219,7 @@ main(int argc, char **argv)
 		dont_have_tty = 1;
 	}
 
-	if (dont_have_tty && mode != 'n')
+	if (dont_have_tty && mode != 'n' && mode != 'N')
 	{
 		printf("%s: Attaching to a session requires a terminal.\n",
 			progname);
@@ -235,10 +239,12 @@ main(int argc, char **argv)
 		return attach_main(0);
 	}
 	else if (mode == 'n')
-		return master_main(argv, 0);
+		return master_main(argv, 0, 0);
+	else if (mode == 'N')
+		return master_main(argv, 0, 1);
 	else if (mode == 'c')
 	{
-		if (master_main(argv, 1) != 0)
+		if (master_main(argv, 1, 0) != 0)
 			return 1;
 		return attach_main(0);
 	}
@@ -252,7 +258,7 @@ main(int argc, char **argv)
 			{
 				if (errno == ECONNREFUSED)
 					unlink(sockname);
-				if (master_main(argv, 1) != 0)
+				if (master_main(argv, 1, 0) != 0)
 					return 1;
 			}
 			return attach_main(0);

master.c

@@ -543,7 +543,7 @@ master_process(int s, char **argv, int waitattach, int statusfd)
 }
 
 int
-master_main(char **argv, int waitattach)
+master_main(char **argv, int waitattach, int dontfork)
 {
 	int fd[2] = {-1, -1};
 	int s;
@@ -566,7 +566,16 @@ master_main(char **argv, int waitattach)
 
 	/* If FD_CLOEXEC works, create a pipe and use it to report any errors
 	** that occur while trying to execute the program. */
-	if (pipe(fd) >= 0)
+	if (dontfork)
+	{
+		fd[1] = dup(2);
+		if (fcntl(fd[1], F_SETFD, FD_CLOEXEC) < 0)
+		{
+			close(fd[1]);
+			fd[1] = -1;
+		}
+	}
+	else if (pipe(fd) >= 0)
 	{
 		if (fcntl(fd[0], F_SETFD, FD_CLOEXEC) < 0 ||
 		    fcntl(fd[1], F_SETFD, FD_CLOEXEC) < 0)
@@ -578,6 +587,12 @@ master_main(char **argv, int waitattach)
 	}
 #endif
 
+	if (dontfork)
+	{
+		master_process(s, argv, waitattach, fd[1]);
+		return 0;
+	}
+
 	/* Fork off so we can daemonize and such */
 	pid = fork();
 	if (pid < 0)