X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=shell%2Fcttyhack.c;h=bde2acdc93db82012a7ef4c61428d2b20454e554;hb=020465218ccff1195a47a890037db37d0395c9d9;hp=cdd0ed1d6dd39fc9605344af957da0fb52c43776;hpb=6d709972cdad4848908813c673b2f5fdc9e3c4c0;p=oweals%2Fbusybox.git

diff --git a/shell/cttyhack.c b/shell/cttyhack.c
index cdd0ed1d6..bde2acdc9 100644
--- a/shell/cttyhack.c
+++ b/shell/cttyhack.c
@@ -1,16 +1,18 @@
-/* This code is adapted from busybox project
- *
+/* vi: set sw=4 ts=4: */
+/*
  * Licensed under GPLv2
+ *
+ * Copyright (c) 2007 Denys Vlasenko <vda.linux@googlemail.com>
  */
 #include "libbb.h"
 
 /* From <linux/vt.h> */
 struct vt_stat {
-	unsigned short v_active;	/* active vt */
-	unsigned short v_signal;	/* signal to send */
-	unsigned short v_state;	/* vt bitmask */
+	unsigned short v_active;        /* active vt */
+	unsigned short v_signal;        /* signal to send */
+	unsigned short v_state;         /* vt bitmask */
 };
-enum { VT_GETSTATE = 0x5603 };	/* get global vt state info */
+enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
 
 /* From <linux/serial.h> */
 struct serial_struct {
@@ -26,8 +28,8 @@ struct serial_struct {
 	char	io_type;
 	char	reserved_char[1];
 	int	hub6;
-	unsigned short	closing_wait; /* time to wait before closing */
-	unsigned short	closing_wait2; /* no longer used... */
+	unsigned short	closing_wait;   /* time to wait before closing */
+	unsigned short	closing_wait2;  /* no longer used... */
 	unsigned char	*iomem_base;
 	unsigned short	iomem_reg_shift;
 	unsigned int	port_high;
@@ -35,8 +37,8 @@ struct serial_struct {
 	int	reserved[1];
 };
 
-int cttyhack_main(int argc, char **argv) ATTRIBUTE_NORETURN;
-int cttyhack_main(int argc, char **argv)
+int cttyhack_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int cttyhack_main(int argc UNUSED_PARAM, char **argv)
 {
 	int fd;
 	char console[sizeof(int)*3 + 16];
@@ -51,23 +53,34 @@ int cttyhack_main(int argc, char **argv)
 	}
 
 	strcpy(console, "/dev/tty");
-	if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
-		/* this is a serial console */
-		sprintf(console + 8, "S%d", u.sr.line);
-	} else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
-		/* this is linux virtual tty */
-		sprintf(console + 8, "S%d" + 1, u.vt.v_active);
-	}
-
-	if (console[8]) {
-		fd = xopen(console, O_RDWR);
-		//bb_error_msg("switching to '%s'", console);
-		dup2(fd, 0);
-		dup2(fd, 1);
-		dup2(fd, 2);
-		while (fd > 2) close(fd--);
+	fd = open(console, O_RDWR);
+	if (fd >= 0) {
+		/* We already have ctty, nothing to do */
+		close(fd);
+	} else {
+		/* We don't have ctty (or don't have "/dev/tty" node...) */
+		if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
+			/* this is a serial console */
+			sprintf(console + 8, "S%d", u.sr.line);
+		} else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
+			/* this is linux virtual tty */
+			sprintf(console + 8, "S%d" + 1, u.vt.v_active);
+		}
+		if (console[8]) {
+			fd = xopen(console, O_RDWR);
+			//bb_error_msg("switching to '%s'", console);
+			dup2(fd, 0);
+			dup2(fd, 1);
+			dup2(fd, 2);
+			while (fd > 2)
+				close(fd--);
+			/* Some other session may have it as ctty,
+			 * steal it from them:
+			 */
+			ioctl(0, TIOCSCTTY, 1);
+		}
 	}
 
-	execvp(argv[0], argv);
-	bb_perror_msg_and_die("cannot exec '%s'", argv[0]);
+	BB_EXECVP(argv[0], argv);
+	bb_perror_msg_and_die("can't execute '%s'", argv[0]);
 }