text: /* $OpenBSD$ */
  
  /*
   * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
   *
   * 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 <stdlib.h>
  #include <string.h>
  #include <time.h>
  
  #include "tmux.h"
  
  /*
   * Based on the description by Paul Williams at:
   *
   * http://vt100.net/emu/dec_ansi_parser
   *
   * With the following changes:
   *
   * - 7-bit only.
   *
   * - Support for UTF-8.
   *
   * - OSC (but not APC) may be terminated by \007 as well as ST.
   *
   * - A state for APC similar to OSC. Some terminals appear to use this to set
   *   the title.
   *
   * - A state for the screen \033k...\033\\ sequence to rename a window. This is
   *   pretty stupid but not supporting it is more trouble than it is worth.
   *
   * - Special handling for ESC inside a DCS to allow arbitrary byte sequences to
   *   be passed to the underlying terminals.
   */
  
  /* Input parser cell. */
  struct input_cell {
  	struct grid_cell	cell;
  	int			set;
  	int			g0set;	/* 1 if ACS */
  	int			g1set;	/* 1 if ACS */
  };
  
  /* Input parser context. */
  struct input_ctx {
  	struct window_pane     *wp;
  	struct screen_write_ctx ctx;
  
  	struct input_cell	cell;
  
  	struct input_cell	old_cell;
  	u_int 			old_cx;
  	u_int			old_cy;
  
  	u_char			interm_buf[4];
  	size_t			interm_len;
  
  	u_char			param_buf[64];
  	size_t			param_len;
  
  #define INPUT_BUF_START 32
  #define INPUT_BUF_LIMIT 1048576
  	u_char		       *input_buf;
  	size_t			input_len;
  	size_t			input_space;
  
  	int			param_list[24];	/* -1 not present */
  	u_int			param_list_len;
  
  	struct utf8_data	utf8data;
  
  	int			ch;
  	int			flags;
  #define INPUT_DISCARD 0x1
  
  	const struct input_state *state;
  
  	/*
  	 * All input received since we were last in the ground state. Sent to
  	 * control clients on connection.
  	 */
  	struct evbuffer	 	*since_ground;
  };
  
  /* Helper functions. */
  struct input_transition;
  int	input_split(struct input_ctx *);
  int	input_get(struct input_ctx *, u_int, int, int);
  void	input_reply(struct input_ctx *, const char *, ...);
  void	input_set_state(struct window_pane *, const struct input_transition *);
  void	input_reset_cell(struct input_ctx *);
  
  /* Transition entry/exit handlers. */
  void	input_clear(struct input_ctx *);
  void	input_ground(struct input_ctx *);
  void	input_enter_osc(struct input_ctx *);
  void	input_exit_osc(struct input_ctx *);
  void	input_enter_apc(struct input_ctx *);
  void	input_exit_apc(struct input_ctx *);
  void	input_enter_rename(struct input_ctx *);
  void	input_exit_rename(struct input_ctx *);
  
  /* Input state handlers. */
  int	input_print(struct input_ctx *);
  int	input_intermediate(struct input_ctx *);
  int	input_parameter(struct input_ctx *);
  int	input_input(struct input_ctx *);
  int	input_c0_dispatch(struct input_ctx *);
  int	input_esc_dispatch(struct input_ctx *);
  int	input_csi_dispatch(struct input_ctx *);
  void	input_csi_dispatch_rm(struct input_ctx *);
  void	input_csi_dispatch_rm_private(struct input_ctx *);
  void	input_csi_dispatch_sm(struct input_ctx *);
  void	input_csi_dispatch_sm_private(struct input_ctx *);
  void	input_csi_dispatch_winops(struct input_ctx *);
  void	input_csi_dispatch_sgr_256(struct input_ctx *, int, u_int *);
  void	input_csi_dispatch_sgr_rgb(struct input_ctx *, int, u_int *);
  void	input_csi_dispatch_sgr(struct input_ctx *);
  int	input_dcs_dispatch(struct input_ctx *);
  int	input_utf8_open(struct input_ctx *);
  int	input_utf8_add(struct input_ctx *);
  int	input_utf8_close(struct input_ctx *);
  
  /* Command table comparison function. */
  int	input_table_compare(const void *, const void *);
  
  /* Command table entry. */
  struct input_table_entry {
  	int		ch;
  	const char     *interm;
  	int		type;
  };
  
  /* Escape commands. */
  enum input_esc_type {
  	INPUT_ESC_DECALN,
  	INPUT_ESC_DECKPAM,
  	INPUT_ESC_DECKPNM,
  	INPUT_ESC_DECRC,
  	INPUT_ESC_DECSC,
  	INPUT_ESC_HTS,
  	INPUT_ESC_IND,
  	INPUT_ESC_NEL,
  	INPUT_ESC_RI,
  	INPUT_ESC_RIS,
  	INPUT_ESC_SCSG0_OFF,
  	INPUT_ESC_SCSG0_ON,
  	INPUT_ESC_SCSG1_OFF,
  	INPUT_ESC_SCSG1_ON,
  };
  
  /* Escape command table. */
  const struct input_table_entry input_esc_table[] = {
  	{ '0', "(", INPUT_ESC_SCSG0_ON },
  	{ '0', ")", INPUT_ESC_SCSG1_ON },
  	{ '7', "",  INPUT_ESC_DECSC },
  	{ '8', "",  INPUT_ESC_DECRC },
  	{ '8', "#", INPUT_ESC_DECALN },
  	{ '=', "",  INPUT_ESC_DECKPAM },
  	{ '>', "",  INPUT_ESC_DECKPNM },
  	{ 'B', "(", INPUT_ESC_SCSG0_OFF },
  	{ 'B', ")", INPUT_ESC_SCSG1_OFF },
  	{ 'D', "",  INPUT_ESC_IND },
  	{ 'E', "",  INPUT_ESC_NEL },
  	{ 'H', "",  INPUT_ESC_HTS },
  	{ 'M', "",  INPUT_ESC_RI },
  	{ 'c', "",  INPUT_ESC_RIS },
  };
  
  /* Control (CSI) commands. */
  enum input_csi_type {
  	INPUT_CSI_CBT,
  	INPUT_CSI_CNL,
  	INPUT_CSI_CPL,
  	INPUT_CSI_CUB,
  	INPUT_CSI_CUD,
  	INPUT_CSI_CUF,
  	INPUT_CSI_CUP,
  	INPUT_CSI_CUU,
  	INPUT_CSI_DA,
  	INPUT_CSI_DA_TWO,
  	INPUT_CSI_DCH,
  	INPUT_CSI_DECSCUSR,
  	INPUT_CSI_DECSTBM,
  	INPUT_CSI_DL,
  	INPUT_CSI_DSR,
  	INPUT_CSI_ECH,
  	INPUT_CSI_ED,
  	INPUT_CSI_EL,
  	INPUT_CSI_HPA,
  	INPUT_CSI_ICH,
  	INPUT_CSI_IL,
  	INPUT_CSI_RCP,
  	INPUT_CSI_RM,
  	INPUT_CSI_RM_PRIVATE,
  	INPUT_CSI_SCP,
  	INPUT_CSI_SGR,
  	INPUT_CSI_SM,
  	INPUT_CSI_SM_PRIVATE,
  	INPUT_CSI_TBC,
  	INPUT_CSI_VPA,
  	INPUT_CSI_WINOPS,
  };
  
  /* Control (CSI) command table. */
  const struct input_table_entry input_csi_table[] = {
  	{ '@', "",  INPUT_CSI_ICH },
  	{ 'A', "",  INPUT_CSI_CUU },
  	{ 'B', "",  INPUT_CSI_CUD },
  	{ 'C', "",  INPUT_CSI_CUF },
  	{ 'D', "",  INPUT_CSI_CUB },
  	{ 'E', "",  INPUT_CSI_CNL },
  	{ 'F', "",  INPUT_CSI_CPL },
  	{ 'G', "",  INPUT_CSI_HPA },
  	{ 'H', "",  INPUT_CSI_CUP },
  	{ 'J', "",  INPUT_CSI_ED },
  	{ 'K', "",  INPUT_CSI_EL },
  	{ 'L', "",  INPUT_CSI_IL },
  	{ 'M', "",  INPUT_CSI_DL },
  	{ 'P', "",  INPUT_CSI_DCH },
  	{ 'X', "",  INPUT_CSI_ECH },
  	{ 'Z', "",  INPUT_CSI_CBT },
  	{ 'c', "",  INPUT_CSI_DA },
  	{ 'c', ">", INPUT_CSI_DA_TWO },
  	{ 'd', "",  INPUT_CSI_VPA },
  	{ 'f', "",  INPUT_CSI_CUP },
  	{ 'g', "",  INPUT_CSI_TBC },
  	{ 'h', "",  INPUT_CSI_SM },
  	{ 'h', "?", INPUT_CSI_SM_PRIVATE },
  	{ 'l', "",  INPUT_CSI_RM },
  	{ 'l', "?", INPUT_CSI_RM_PRIVATE },
  	{ 'm', "",  INPUT_CSI_SGR },
  	{ 'n', "",  INPUT_CSI_DSR },
  	{ 'q', " ", INPUT_CSI_DECSCUSR },
  	{ 'r', "",  INPUT_CSI_DECSTBM },
  	{ 's', "",  INPUT_CSI_SCP },
  	{ 't', "",  INPUT_CSI_WINOPS },
  	{ 'u', "",  INPUT_CSI_RCP },
  };
  
  /* Input transition. */
  struct input_transition {
  	int				first;
  	int				last;
  
  	int				(*handler)(struct input_ctx *);
  	const struct input_state       *state;
  };
  
  /* Input state. */
  struct input_state {
  	const char			*name;
  	void				(*enter)(struct input_ctx *);
  	void				(*exit)(struct input_ctx *);
  	const struct input_transition	*transitions;
  };
  
  /* State transitions available from all states. */
  #define INPUT_STATE_ANYWHERE \
  	{ 0x18, 0x18, input_c0_dispatch, &input_state_ground }, \
  	{ 0x1a, 0x1a, input_c0_dispatch, &input_state_ground }, \
  	{ 0x1b, 0x1b, NULL,		 &input_state_esc_enter }
  
  /* Forward declarations of state tables. */
  const struct input_transition input_state_ground_table[];
  const struct input_transition input_state_esc_enter_table[];
  const struct input_transition input_state_esc_intermediate_table[];
  const struct input_transition input_state_csi_enter_table[];
  const struct input_transition input_state_csi_parameter_table[];
  const struct input_transition input_state_csi_intermediate_table[];
  const struct input_transition input_state_csi_ignore_table[];
  const struct input_transition input_state_dcs_enter_table[];
  const struct input_transition input_state_dcs_parameter_table[];
  const struct input_transition input_state_dcs_intermediate_table[];
  const struct input_transition input_state_dcs_handler_table[];
  const struct input_transition input_state_dcs_escape_table[];
  const struct input_transition input_state_dcs_ignore_table[];
  const struct input_transition input_state_osc_string_table[];
  const struct input_transition input_state_apc_string_table[];
  const struct input_transition input_state_rename_string_table[];
  const struct input_transition input_state_consume_st_table[];
  const struct input_transition input_state_utf8_three_table[];
  const struct input_transition input_state_utf8_two_table[];
  const struct input_transition input_state_utf8_one_table[];
  
  /* ground state definition. */
  const struct input_state input_state_ground = {
  	"ground",
  	input_ground, NULL,
  	input_state_ground_table
  };
  
  /* esc_enter state definition. */
  const struct input_state input_state_esc_enter = {
  	"esc_enter",
  	input_clear, NULL,
  	input_state_esc_enter_table
  };
  
  /* esc_intermediate state definition. */
  const struct input_state input_state_esc_intermediate = {
  	"esc_intermediate",
  	NULL, NULL,
  	input_state_esc_intermediate_table
  };
  
  /* csi_enter state definition. */
  const struct input_state input_state_csi_enter = {
  	"csi_enter",
  	input_clear, NULL,
  	input_state_csi_enter_table
  };
  
  /* csi_parameter state definition. */
  const struct input_state input_state_csi_parameter = {
  	"csi_parameter",
  	NULL, NULL,
  	input_state_csi_parameter_table
  };
  
  /* csi_intermediate state definition. */
  const struct input_state input_state_csi_intermediate = {
  	"csi_intermediate",
  	NULL, NULL,
  	input_state_csi_intermediate_table
  };
  
  /* csi_ignore state definition. */
  const struct input_state input_state_csi_ignore = {
  	"csi_ignore",
  	NULL, NULL,
  	input_state_csi_ignore_table
  };
  
  /* dcs_enter state definition. */
  const struct input_state input_state_dcs_enter = {
  	"dcs_enter",
  	input_clear, NULL,
  	input_state_dcs_enter_table
  };
  
  /* dcs_parameter state definition. */
  const struct input_state input_state_dcs_parameter = {
  	"dcs_parameter",
  	NULL, NULL,
  	input_state_dcs_parameter_table
  };
  
  /* dcs_intermediate state definition. */
  const struct input_state input_state_dcs_intermediate = {
  	"dcs_intermediate",
  	NULL, NULL,
  	input_state_dcs_intermediate_table
  };
  
  /* dcs_handler state definition. */
  const struct input_state input_state_dcs_handler = {
  	"dcs_handler",
  	NULL, NULL,
  	input_state_dcs_handler_table
  };
  
  /* dcs_escape state definition. */
  const struct input_state input_state_dcs_escape = {
  	"dcs_escape",
  	NULL, NULL,
  	input_state_dcs_escape_table
  };
  
  /* dcs_ignore state definition. */
  const struct input_state input_state_dcs_ignore = {
  	"dcs_ignore",
  	NULL, NULL,
  	input_state_dcs_ignore_table
  };
  
  /* osc_string state definition. */
  const struct input_state input_state_osc_string = {
  	"osc_string",
  	input_enter_osc, input_exit_osc,
  	input_state_osc_string_table
  };
  
  /* apc_string state definition. */
  const struct input_state input_state_apc_string = {
  	"apc_string",
  	input_enter_apc, input_exit_apc,
  	input_state_apc_string_table
  };
  
  /* rename_string state definition. */
  const struct input_state input_state_rename_string = {
  	"rename_string",
  	input_enter_rename, input_exit_rename,
  	input_state_rename_string_table
  };
  
  /* consume_st state definition. */
  const struct input_state input_state_consume_st = {
  	"consume_st",
  	NULL, NULL,
  	input_state_consume_st_table
  };
  
  /* utf8_three state definition. */
  const struct input_state input_state_utf8_three = {
  	"utf8_three",
  	NULL, NULL,
  	input_state_utf8_three_table
  };
  
  /* utf8_two state definition. */
  const struct input_state input_state_utf8_two = {
  	"utf8_two",
  	NULL, NULL,
  	input_state_utf8_two_table
  };
  
  /* utf8_one state definition. */
  const struct input_state input_state_utf8_one = {
  	"utf8_one",
  	NULL, NULL,
  	input_state_utf8_one_table
  };
  
  /* ground state table. */
  const struct input_transition input_state_ground_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch, NULL },
  	{ 0x19, 0x19, input_c0_dispatch, NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch, NULL },
  	{ 0x20, 0x7e, input_print,	 NULL },
  	{ 0x7f, 0x7f, NULL,		 NULL },
  	{ 0x80, 0xc1, input_print,	 NULL },
  	{ 0xc2, 0xdf, input_utf8_open,	 &input_state_utf8_one },
  	{ 0xe0, 0xef, input_utf8_open,	 &input_state_utf8_two },
  	{ 0xf0, 0xf4, input_utf8_open,	 &input_state_utf8_three },
  	{ 0xf5, 0xff, input_print,	 NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* esc_enter state table. */
  const struct input_transition input_state_esc_enter_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch,  NULL },
  	{ 0x19, 0x19, input_c0_dispatch,  NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch,  NULL },
  	{ 0x20, 0x2f, input_intermediate, &input_state_esc_intermediate },
  	{ 0x30, 0x4f, input_esc_dispatch, &input_state_ground },
  	{ 0x50, 0x50, NULL,		  &input_state_dcs_enter },
  	{ 0x51, 0x57, input_esc_dispatch, &input_state_ground },
  	{ 0x58, 0x58, NULL,		  &input_state_consume_st },
  	{ 0x59, 0x59, input_esc_dispatch, &input_state_ground },
  	{ 0x5a, 0x5a, input_esc_dispatch, &input_state_ground },
  	{ 0x5b, 0x5b, NULL,		  &input_state_csi_enter },
  	{ 0x5c, 0x5c, input_esc_dispatch, &input_state_ground },
  	{ 0x5d, 0x5d, NULL,		  &input_state_osc_string },
  	{ 0x5e, 0x5e, NULL,		  &input_state_consume_st },
  	{ 0x5f, 0x5f, NULL,		  &input_state_apc_string },
  	{ 0x60, 0x6a, input_esc_dispatch, &input_state_ground },
  	{ 0x6b, 0x6b, NULL,		  &input_state_rename_string },
  	{ 0x6c, 0x7e, input_esc_dispatch, &input_state_ground },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* esc_interm state table. */
  const struct input_transition input_state_esc_intermediate_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch,  NULL },
  	{ 0x19, 0x19, input_c0_dispatch,  NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch,  NULL },
  	{ 0x20, 0x2f, input_intermediate, NULL },
  	{ 0x30, 0x7e, input_esc_dispatch, &input_state_ground },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* csi_enter state table. */
  const struct input_transition input_state_csi_enter_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch,  NULL },
  	{ 0x19, 0x19, input_c0_dispatch,  NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch,  NULL },
  	{ 0x20, 0x2f, input_intermediate, &input_state_csi_intermediate },
  	{ 0x30, 0x39, input_parameter,	  &input_state_csi_parameter },
  	{ 0x3a, 0x3a, NULL,		  &input_state_csi_ignore },
  	{ 0x3b, 0x3b, input_parameter,	  &input_state_csi_parameter },
  	{ 0x3c, 0x3f, input_intermediate, &input_state_csi_parameter },
  	{ 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* csi_parameter state table. */
  const struct input_transition input_state_csi_parameter_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch,  NULL },
  	{ 0x19, 0x19, input_c0_dispatch,  NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch,  NULL },
  	{ 0x20, 0x2f, input_intermediate, &input_state_csi_intermediate },
  	{ 0x30, 0x39, input_parameter,	  NULL },
  	{ 0x3a, 0x3a, NULL,		  &input_state_csi_ignore },
  	{ 0x3b, 0x3b, input_parameter,	  NULL },
  	{ 0x3c, 0x3f, NULL,		  &input_state_csi_ignore },
  	{ 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* csi_intermediate state table. */
  const struct input_transition input_state_csi_intermediate_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch,  NULL },
  	{ 0x19, 0x19, input_c0_dispatch,  NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch,  NULL },
  	{ 0x20, 0x2f, input_intermediate, NULL },
  	{ 0x30, 0x3f, NULL,		  &input_state_csi_ignore },
  	{ 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* csi_ignore state table. */
  const struct input_transition input_state_csi_ignore_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, input_c0_dispatch, NULL },
  	{ 0x19, 0x19, input_c0_dispatch, NULL },
  	{ 0x1c, 0x1f, input_c0_dispatch, NULL },
  	{ 0x20, 0x3f, NULL,		 NULL },
  	{ 0x40, 0x7e, NULL,		 &input_state_ground },
  	{ 0x7f, 0xff, NULL,		 NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_enter state table. */
  const struct input_transition input_state_dcs_enter_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,		  NULL },
  	{ 0x19, 0x19, NULL,		  NULL },
  	{ 0x1c, 0x1f, NULL,		  NULL },
  	{ 0x20, 0x2f, input_intermediate, &input_state_dcs_intermediate },
  	{ 0x30, 0x39, input_parameter,	  &input_state_dcs_parameter },
  	{ 0x3a, 0x3a, NULL,		  &input_state_dcs_ignore },
  	{ 0x3b, 0x3b, input_parameter,	  &input_state_dcs_parameter },
  	{ 0x3c, 0x3f, input_intermediate, &input_state_dcs_parameter },
  	{ 0x40, 0x7e, input_input,	  &input_state_dcs_handler },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_parameter state table. */
  const struct input_transition input_state_dcs_parameter_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,		  NULL },
  	{ 0x19, 0x19, NULL,		  NULL },
  	{ 0x1c, 0x1f, NULL,		  NULL },
  	{ 0x20, 0x2f, input_intermediate, &input_state_dcs_intermediate },
  	{ 0x30, 0x39, input_parameter,	  NULL },
  	{ 0x3a, 0x3a, NULL,		  &input_state_dcs_ignore },
  	{ 0x3b, 0x3b, input_parameter,	  NULL },
  	{ 0x3c, 0x3f, NULL,		  &input_state_dcs_ignore },
  	{ 0x40, 0x7e, input_input,	  &input_state_dcs_handler },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_interm state table. */
  const struct input_transition input_state_dcs_intermediate_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,		  NULL },
  	{ 0x19, 0x19, NULL,		  NULL },
  	{ 0x1c, 0x1f, NULL,		  NULL },
  	{ 0x20, 0x2f, input_intermediate, NULL },
  	{ 0x30, 0x3f, NULL,		  &input_state_dcs_ignore },
  	{ 0x40, 0x7e, input_input,	  &input_state_dcs_handler },
  	{ 0x7f, 0xff, NULL,		  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_handler state table. */
  const struct input_transition input_state_dcs_handler_table[] = {
  	/* No INPUT_STATE_ANYWHERE */
  
  	{ 0x00, 0x1a, input_input,  NULL },
  	{ 0x1b, 0x1b, NULL,	    &input_state_dcs_escape },
  	{ 0x1c, 0xff, input_input,  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_escape state table. */
  const struct input_transition input_state_dcs_escape_table[] = {
  	/* No INPUT_STATE_ANYWHERE */
  
  	{ 0x00, 0x5b, input_input,	  &input_state_dcs_handler },
  	{ 0x5c, 0x5c, input_dcs_dispatch, &input_state_ground },
  	{ 0x5d, 0xff, input_input,	  &input_state_dcs_handler },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* dcs_ignore state table. */
  const struct input_transition input_state_dcs_ignore_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,	    NULL },
  	{ 0x19, 0x19, NULL,	    NULL },
  	{ 0x1c, 0x1f, NULL,	    NULL },
  	{ 0x20, 0xff, NULL,	    NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* osc_string state table. */
  const struct input_transition input_state_osc_string_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x06, NULL,	    NULL },
  	{ 0x07, 0x07, NULL,	    &input_state_ground },
  	{ 0x08, 0x17, NULL,	    NULL },
  	{ 0x19, 0x19, NULL,	    NULL },
  	{ 0x1c, 0x1f, NULL,	    NULL },
  	{ 0x20, 0xff, input_input,  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* apc_string state table. */
  const struct input_transition input_state_apc_string_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,	    NULL },
  	{ 0x19, 0x19, NULL,	    NULL },
  	{ 0x1c, 0x1f, NULL,	    NULL },
  	{ 0x20, 0xff, input_input,  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* rename_string state table. */
  const struct input_transition input_state_rename_string_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,	    NULL },
  	{ 0x19, 0x19, NULL,	    NULL },
  	{ 0x1c, 0x1f, NULL,	    NULL },
  	{ 0x20, 0xff, input_input,  NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* consume_st state table. */
  const struct input_transition input_state_consume_st_table[] = {
  	INPUT_STATE_ANYWHERE,
  
  	{ 0x00, 0x17, NULL,	    NULL },
  	{ 0x19, 0x19, NULL,	    NULL },
  	{ 0x1c, 0x1f, NULL,	    NULL },
  	{ 0x20, 0xff, NULL,	    NULL },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* utf8_three state table. */
  const struct input_transition input_state_utf8_three_table[] = {
  	/* No INPUT_STATE_ANYWHERE */
  
  	{ 0x00, 0x7f, NULL,		&input_state_ground },
  	{ 0x80, 0xbf, input_utf8_add,	&input_state_utf8_two },
  	{ 0xc0, 0xff, NULL,		&input_state_ground },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* utf8_two state table. */
  const struct input_transition input_state_utf8_two_table[] = {
  	/* No INPUT_STATE_ANYWHERE */
  
  	{ 0x00, 0x7f, NULL,	      &input_state_ground },
  	{ 0x80, 0xbf, input_utf8_add, &input_state_utf8_one },
  	{ 0xc0, 0xff, NULL,	      &input_state_ground },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* utf8_one state table. */
  const struct input_transition input_state_utf8_one_table[] = {
  	/* No INPUT_STATE_ANYWHERE */
  
  	{ 0x00, 0x7f, NULL,		&input_state_ground },
  	{ 0x80, 0xbf, input_utf8_close, &input_state_ground },
  	{ 0xc0, 0xff, NULL,		&input_state_ground },
  
  	{ -1, -1, NULL, NULL }
  };
  
  /* Input table compare. */
  int
  input_table_compare(const void *key, const void *value)
  {
  	const struct input_ctx		*ictx = key;
  	const struct input_table_entry	*entry = value;
  
  	if (ictx->ch != entry->ch)
  		return (ictx->ch - entry->ch);
  	return (strcmp(ictx->interm_buf, entry->interm));
  }
  
  /* Reset cell state to default. */
  void
  input_reset_cell(struct input_ctx *ictx)
  {
  	memcpy(&ictx->cell.cell, &grid_default_cell, sizeof ictx->cell.cell);
  	ictx->cell.set = 0;
  	ictx->cell.g0set = ictx->cell.g1set = 0;
  
  	memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  	ictx->old_cx = 0;
  	ictx->old_cy = 0;
  }
  
  /* Initialise input parser. */
  void
  input_init(struct window_pane *wp)
  {
  	struct input_ctx	*ictx;
  
  	ictx = wp->ictx = xcalloc(1, sizeof *ictx);
  
  	input_reset_cell(ictx);
  
  	*ictx->interm_buf = '\0';
  	ictx->interm_len = 0;
  
  	*ictx->param_buf = '\0';
  	ictx->param_len = 0;
  
  	ictx->input_space = INPUT_BUF_START;
  	ictx->input_buf = xmalloc(INPUT_BUF_START);
  
  	*ictx->input_buf = '\0';
  	ictx->input_len = 0;
  
  	ictx->state = &input_state_ground;
  	ictx->flags = 0;
  
  	ictx->since_ground = evbuffer_new();
  }
  
  /* Destroy input parser. */
  void
  input_free(struct window_pane *wp)
  {
  	struct input_ctx	*ictx = wp->ictx;
  
  	free(ictx->input_buf);
  	evbuffer_free(ictx->since_ground);
  
  	free (ictx);
  	wp->ictx = NULL;
  }
  
  /* Reset input state and clear screen. */
  void
  input_reset(struct window_pane *wp)
  {
  	struct input_ctx	*ictx = wp->ictx;
  
  	memcpy(&ictx->cell, &grid_default_cell, sizeof ictx->cell);
  	memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  	ictx->old_cx = 0;
  	ictx->old_cy = 0;
  
  	if (wp->mode == NULL)
  		screen_write_start(&ictx->ctx, wp, &wp->base);
  	else
  		screen_write_start(&ictx->ctx, NULL, &wp->base);
  	screen_write_reset(&ictx->ctx);
  	screen_write_stop(&ictx->ctx);
  }
  
  /* Return pending data. */
  struct evbuffer *
  input_pending(struct window_pane *wp)
  {
  	return (wp->ictx->since_ground);
  }
  
  /* Change input state. */
  void
  input_set_state(struct window_pane *wp, const struct input_transition *itr)
  {
  	struct input_ctx	*ictx = wp->ictx;
  
  	if (ictx->state->exit != NULL)
  		ictx->state->exit(ictx);
  	ictx->state = itr->state;
  	if (ictx->state->enter != NULL)
  		ictx->state->enter(ictx);
  }
  
  /* Parse input. */
  void
  input_parse(struct window_pane *wp)
  {
  	struct input_ctx		*ictx = wp->ictx;
  	const struct input_transition	*itr;
  	struct evbuffer			*evb = wp->event->input;
  	u_char				*buf;
  	size_t				 len, off;
  
  	if (EVBUFFER_LENGTH(evb) == 0)
  		return;
  
  	wp->window->flags |= WINDOW_ACTIVITY;
  	wp->window->flags &= ~WINDOW_SILENCE;
  
  	if (gettimeofday(&wp->window->activity_time, NULL) != 0)
  		fatal("gettimeofday failed");
  
  	/*
  	 * Open the screen. Use NULL wp if there is a mode set as don't want to
  	 * update the tty.
  	 */
  	if (wp->mode == NULL)
  		screen_write_start(&ictx->ctx, wp, &wp->base);
  	else
  		screen_write_start(&ictx->ctx, NULL, &wp->base);
  	ictx->wp = wp;
  
  	buf = EVBUFFER_DATA(evb);
  	len = EVBUFFER_LENGTH(evb);
  	notify_input(wp, evb);
  	off = 0;
  
  	/* Parse the input. */
  	while (off < len) {
  		ictx->ch = buf[off++];
  		log_debug("%s: '%c' %s", __func__, ictx->ch, ictx->state->name);
  
  		/* Find the transition. */
  		itr = ictx->state->transitions;
  		while (itr->first != -1 && itr->last != -1) {
  			if (ictx->ch >= itr->first && ictx->ch <= itr->last)
  				break;
  			itr++;
  		}
  		if (itr->first == -1 || itr->last == -1) {
  			/* No transition? Eh? */
  			fatalx("No transition from state!");
  		}
  
  		/*
  		 * Execute the handler, if any. Don't switch state if it
  		 * returns non-zero.
  		 */
  		if (itr->handler != NULL && itr->handler(ictx) != 0)
  			continue;
  
  		/* And switch state, if necessary. */
  		if (itr->state != NULL)
  			input_set_state(wp, itr);
  
  		/* If not in ground state, save input. */
  		if (ictx->state != &input_state_ground)
  			evbuffer_add(ictx->since_ground, &ictx->ch, 1);
  	}
  
  	/* Close the screen. */
  	screen_write_stop(&ictx->ctx);
  
  	evbuffer_drain(evb, len);
  }
  
  /* Split the parameter list (if any). */
  int
  input_split(struct input_ctx *ictx)
  
  {
  	const char	*errstr;
  	char		*ptr, *out;
  	int		 n;
  
  	ictx->param_list_len = 0;
  	if (ictx->param_len == 0)
  		return (0);
  
  	ptr = ictx->param_buf;
  	while ((out = strsep(&ptr, ";")) != NULL) {
  		if (*out == '\0')
  			n = -1;
  		else {
  			n = strtonum(out, 0, INT_MAX, &errstr);
  			if (errstr != NULL)
  				return (-1);
  		}
  
  		ictx->param_list[ictx->param_list_len++] = n;
  		if (ictx->param_list_len == nitems(ictx->param_list))
  			return (-1);
  	}
  
  	return (0);
  }
  
  /* Get an argument or return default value. */
  int
  input_get(struct input_ctx *ictx, u_int validx, int minval, int defval)
  {
  	int	retval;
  
  	if (validx >= ictx->param_list_len)
  	    return (defval);
  
  	retval = ictx->param_list[validx];
  	if (retval == -1)
  		return (defval);
  	if (retval < minval)
  		return (minval);
  	return (retval);
  }
  
  /* Reply to terminal query. */
  void
  input_reply(struct input_ctx *ictx, const char *fmt, ...)
  {
  	va_list	ap;
  	char   *reply;
  
  	va_start(ap, fmt);
  	vasprintf(&reply, fmt, ap);
  	va_end(ap);
  
  	bufferevent_write(ictx->wp->event, reply, strlen(reply));
  	free(reply);
  }
  
  /* Clear saved state. */
  void
  input_clear(struct input_ctx *ictx)
  {
  	*ictx->interm_buf = '\0';
  	ictx->interm_len = 0;
  
  	*ictx->param_buf = '\0';
  	ictx->param_len = 0;
  
  	*ictx->input_buf = '\0';
  	ictx->input_len = 0;
  
  	ictx->flags &= ~INPUT_DISCARD;
  }
  
  /* Reset for ground state. */
  void
  input_ground(struct input_ctx *ictx)
  {
  	evbuffer_drain(ictx->since_ground, EVBUFFER_LENGTH(ictx->since_ground));
  
  	if (ictx->input_space > INPUT_BUF_START) {
  		ictx->input_space = INPUT_BUF_START;
  		ictx->input_buf = xrealloc(ictx->input_buf, INPUT_BUF_START);
  	}
  }
  
  /* Output this character to the screen. */
  int
  input_print(struct input_ctx *ictx)
  {
  	int	set;
  
  	set = ictx->cell.set == 0 ? ictx->cell.g0set : ictx->cell.g1set;
  	if (set == 1)
  		ictx->cell.cell.attr |= GRID_ATTR_CHARSET;
  	else
  		ictx->cell.cell.attr &= ~GRID_ATTR_CHARSET;
  
  	grid_cell_one(&ictx->cell.cell, ictx->ch);
  	screen_write_cell(&ictx->ctx, &ictx->cell.cell);
  
  	ictx->cell.cell.attr &= ~GRID_ATTR_CHARSET;
  
  	return (0);
  }
  
  /* Collect intermediate string. */
  int
  input_intermediate(struct input_ctx *ictx)
  {
  	if (ictx->interm_len == (sizeof ictx->interm_buf) - 1)
  		ictx->flags |= INPUT_DISCARD;
  	else {
  		ictx->interm_buf[ictx->interm_len++] = ictx->ch;
  		ictx->interm_buf[ictx->interm_len] = '\0';
  	}
  
  	return (0);
  }
  
  /* Collect parameter string. */
  int
  input_parameter(struct input_ctx *ictx)
  {
  	if (ictx->param_len == (sizeof ictx->param_buf) - 1)
  		ictx->flags |= INPUT_DISCARD;
  	else {
  		ictx->param_buf[ictx->param_len++] = ictx->ch;
  		ictx->param_buf[ictx->param_len] = '\0';
  	}
  
  	return (0);
  }
  
  /* Collect input string. */
  int
  input_input(struct input_ctx *ictx)
  {
  	size_t available;
  
  	available = ictx->input_space;
  	while (ictx->input_len + 1 >= available) {
  		available *= 2;
  		if (available > INPUT_BUF_LIMIT) {
  			ictx->flags |= INPUT_DISCARD;
  			return (0);
  		}
  		ictx->input_buf = xrealloc(ictx->input_buf, available);
  		ictx->input_space = available;
  	}
  	ictx->input_buf[ictx->input_len++] = ictx->ch;
  	ictx->input_buf[ictx->input_len] = '\0';
  
  	return (0);
  }
  
  /* Execute C0 control sequence. */
  int
  input_c0_dispatch(struct input_ctx *ictx)
  {
  	struct screen_write_ctx	*sctx = &ictx->ctx;
  	struct window_pane	*wp = ictx->wp;
  	struct screen		*s = sctx->s;
  
  	log_debug("%s: '%c", __func__, ictx->ch);
  
  	switch (ictx->ch) {
  	case '\000':	/* NUL */
  		break;
  	case '\007':	/* BEL */
  		wp->window->flags |= WINDOW_BELL;
  		break;
  	case '\010':	/* BS */
  		screen_write_backspace(sctx);
  		break;
  	case '\011':	/* HT */
  		/* Don't tab beyond the end of the line. */
  		if (s->cx >= screen_size_x(s) - 1)
  			break;
  
  		/* Find the next tab point, or use the last column if none. */
  		do {
  			s->cx++;
  			if (bit_test(s->tabs, s->cx))
  				break;
  		} while (s->cx < screen_size_x(s) - 1);
  		break;
  	case '\012':	/* LF */
  	case '\013':	/* VT */
  	case '\014':	/* FF */
  		screen_write_linefeed(sctx, 0);
  		break;
  	case '\015':	/* CR */
  		screen_write_carriagereturn(sctx);
  		break;
  	case '\016':	/* SO */
  		ictx->cell.set = 1;
  		break;
  	case '\017':	/* SI */
  		ictx->cell.set = 0;
  		break;
  	default:
  		log_debug("%s: unknown '%c'", __func__, ictx->ch);
  		break;
  	}
  
  	return (0);
  }
  
  /* Execute escape sequence. */
  int
  input_esc_dispatch(struct input_ctx *ictx)
  {
  	struct screen_write_ctx		*sctx = &ictx->ctx;
  	struct screen			*s = sctx->s;
  	struct input_table_entry	*entry;
  
  	if (ictx->flags & INPUT_DISCARD)
  		return (0);
  	log_debug("%s: '%c', %s", __func__, ictx->ch, ictx->interm_buf);
  
  	entry = bsearch(ictx, input_esc_table, nitems(input_esc_table),
  	    sizeof input_esc_table[0], input_table_compare);
  	if (entry == NULL) {
  		log_debug("%s: unknown '%c'", __func__, ictx->ch);
  		return (0);
  	}
  
  	switch (entry->type) {
  	case INPUT_ESC_RIS:
  		input_reset_cell(ictx);
  		screen_write_reset(sctx);
  		break;
  	case INPUT_ESC_IND:
  		screen_write_linefeed(sctx, 0);
  		break;
  	case INPUT_ESC_NEL:
  		screen_write_carriagereturn(sctx);
  		screen_write_linefeed(sctx, 0);
  		break;
  	case INPUT_ESC_HTS:
  		if (s->cx < screen_size_x(s))
  			bit_set(s->tabs, s->cx);
  		break;
  	case INPUT_ESC_RI:
  		screen_write_reverseindex(sctx);
  		break;
  	case INPUT_ESC_DECKPAM:
  		screen_write_mode_set(sctx, MODE_KKEYPAD);
  		break;
  	case INPUT_ESC_DECKPNM:
  		screen_write_mode_clear(sctx, MODE_KKEYPAD);
  		break;
  	case INPUT_ESC_DECSC:
  		memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  		ictx->old_cx = s->cx;
  		ictx->old_cy = s->cy;
  		break;
  	case INPUT_ESC_DECRC:
  		memcpy(&ictx->cell, &ictx->old_cell, sizeof ictx->cell);
  		screen_write_cursormove(sctx, ictx->old_cx, ictx->old_cy);
  		break;
  	case INPUT_ESC_DECALN:
  		screen_write_alignmenttest(sctx);
  		break;
  	case INPUT_ESC_SCSG0_ON:
  		ictx->cell.g0set = 1;
  		break;
  	case INPUT_ESC_SCSG0_OFF:
  		ictx->cell.g0set = 0;
  		break;
  	case INPUT_ESC_SCSG1_ON:
  		ictx->cell.g1set = 1;
  		break;
  	case INPUT_ESC_SCSG1_OFF:
  		ictx->cell.g1set = 0;
  		break;
  	}
  
  	return (0);
  }
  
  /* Execute control sequence. */
  int
  input_csi_dispatch(struct input_ctx *ictx)
  {
  	struct screen_write_ctx	       *sctx = &ictx->ctx;
  	struct screen		       *s = sctx->s;
  	struct input_table_entry       *entry;
  	int				n, m;
  
  	if (ictx->flags & INPUT_DISCARD)
  		return (0);
  	if (input_split(ictx) != 0)
  		return (0);
  	log_debug("%s: '%c' \"%s\" \"%s\"",
  	    __func__, ictx->ch, ictx->interm_buf, ictx->param_buf);
  
  	entry = bsearch(ictx, input_csi_table, nitems(input_csi_table),
  	    sizeof input_csi_table[0], input_table_compare);
  	if (entry == NULL) {
  		log_debug("%s: unknown '%c'", __func__, ictx->ch);
  		return (0);
  	}
  
  	switch (entry->type) {
  	case INPUT_CSI_CBT:
  		/* Find the previous tab point, n times. */
  		n = input_get(ictx, 0, 1, 1);
  		while (s->cx > 0 && n-- > 0) {
  			do
  				s->cx--;
  			while (s->cx > 0 && !bit_test(s->tabs, s->cx));
  		}
  		break;
  	case INPUT_CSI_CUB:
  		screen_write_cursorleft(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_CUD:
  		screen_write_cursordown(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_CUF:
  		screen_write_cursorright(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_CUP:
  		n = input_get(ictx, 0, 1, 1);
  		m = input_get(ictx, 1, 1, 1);
  		screen_write_cursormove(sctx, m - 1, n - 1);
  		break;
  	case INPUT_CSI_WINOPS:
  		input_csi_dispatch_winops(ictx);
  		break;
  	case INPUT_CSI_CUU:
  		screen_write_cursorup(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_CNL:
  		screen_write_carriagereturn(sctx);
  		screen_write_cursordown(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_CPL:
  		screen_write_carriagereturn(sctx);
  		screen_write_cursorup(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_DA:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 0:
  			input_reply(ictx, "\033[?1;2c");
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_DA_TWO:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 0:
  			input_reply(ictx, "\033[>84;0;0c");
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_ECH:
  		screen_write_clearcharacter(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_DCH:
  		screen_write_deletecharacter(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_DECSTBM:
  		n = input_get(ictx, 0, 1, 1);
  		m = input_get(ictx, 1, 1, screen_size_y(s));
  		screen_write_scrollregion(sctx, n - 1, m - 1);
  		break;
  	case INPUT_CSI_DL:
  		screen_write_deleteline(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_DSR:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 5:
  			input_reply(ictx, "\033[0n");
  			break;
  		case 6:
  			input_reply(ictx, "\033[%u;%uR", s->cy + 1, s->cx + 1);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_ED:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 0:
  			screen_write_clearendofscreen(sctx);
  			break;
  		case 1:
  			screen_write_clearstartofscreen(sctx);
  			break;
  		case 2:
  			screen_write_clearscreen(sctx);
  			break;
  		case 3:
  			switch (input_get(ictx, 1, 0, 0)) {
  			case 0:
  				/*
  				 * Linux console extension to clear history
  				 * (for example before locking the screen).
  				 */
  				screen_write_clearhistory(sctx);
  				break;
  			}
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_EL:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 0:
  			screen_write_clearendofline(sctx);
  			break;
  		case 1:
  			screen_write_clearstartofline(sctx);
  			break;
  		case 2:
  			screen_write_clearline(sctx);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_HPA:
  		n = input_get(ictx, 0, 1, 1);
  		screen_write_cursormove(sctx, n - 1, s->cy);
  		break;
  	case INPUT_CSI_ICH:
  		screen_write_insertcharacter(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_IL:
  		screen_write_insertline(sctx, input_get(ictx, 0, 1, 1));
  		break;
  	case INPUT_CSI_RCP:
  		memcpy(&ictx->cell, &ictx->old_cell, sizeof ictx->cell);
  		screen_write_cursormove(sctx, ictx->old_cx, ictx->old_cy);
  		break;
  	case INPUT_CSI_RM:
  		input_csi_dispatch_rm(ictx);
  		break;
  	case INPUT_CSI_RM_PRIVATE:
  		input_csi_dispatch_rm_private(ictx);
  		break;
  	case INPUT_CSI_SCP:
  		memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  		ictx->old_cx = s->cx;
  		ictx->old_cy = s->cy;
  		break;
  	case INPUT_CSI_SGR:
  		input_csi_dispatch_sgr(ictx);
  		break;
  	case INPUT_CSI_SM:
  		input_csi_dispatch_sm(ictx);
  		break;
  	case INPUT_CSI_SM_PRIVATE:
  		input_csi_dispatch_sm_private(ictx);
  		break;
  	case INPUT_CSI_TBC:
  		switch (input_get(ictx, 0, 0, 0)) {
  		case 0:
  			if (s->cx < screen_size_x(s))
  				bit_clear(s->tabs, s->cx);
  			break;
  		case 3:
  			bit_nclear(s->tabs, 0, screen_size_x(s) - 1);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		break;
  	case INPUT_CSI_VPA:
  		n = input_get(ictx, 0, 1, 1);
  		screen_write_cursormove(sctx, s->cx, n - 1);
  		break;
  	case INPUT_CSI_DECSCUSR:
  		n = input_get(ictx, 0, 0, 0);
  		screen_set_cursor_style(s, n);
  		break;
  	}
  
  	return (0);
  }
  
  /* Handle CSI RM. */
  void
  input_csi_dispatch_rm(struct input_ctx *ictx)
  {
  	u_int	i;
  
  	for (i = 0; i < ictx->param_list_len; i++) {
  		switch (input_get(ictx, i, 0, -1)) {
  		case 4:		/* IRM */
  			screen_write_mode_clear(&ictx->ctx, MODE_INSERT);
  			break;
  		case 34:
  			screen_write_mode_set(&ictx->ctx, MODE_BLINKING);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  	}
  }
  
  /* Handle CSI private RM. */
  void
  input_csi_dispatch_rm_private(struct input_ctx *ictx)
  {
  	struct window_pane	*wp = ictx->wp;
  	u_int			 i;
  
  	for (i = 0; i < ictx->param_list_len; i++) {
  		switch (input_get(ictx, i, 0, -1)) {
  		case 1:		/* DECCKM */
  			screen_write_mode_clear(&ictx->ctx, MODE_KCURSOR);
  			break;
  		case 3:		/* DECCOLM */
  			screen_write_cursormove(&ictx->ctx, 0, 0);
  			screen_write_clearscreen(&ictx->ctx);
  			break;
  		case 7:		/* DECAWM */
  			screen_write_mode_clear(&ictx->ctx, MODE_WRAP);
  			break;
  		case 12:
  			screen_write_mode_clear(&ictx->ctx, MODE_BLINKING);
  			break;
  		case 25:	/* TCEM */
  			screen_write_mode_clear(&ictx->ctx, MODE_CURSOR);
  			break;
  		case 1000:
  		case 1001:
  		case 1002:
  			screen_write_mode_clear(&ictx->ctx, ALL_MOUSE_MODES);
  			break;
  		case 1004:
  			screen_write_mode_clear(&ictx->ctx, MODE_FOCUSON);
  			break;
  		case 1005:
  			screen_write_mode_clear(&ictx->ctx, MODE_MOUSE_UTF8);
  			break;
  		case 1006:
  			screen_write_mode_clear(&ictx->ctx, MODE_MOUSE_SGR);
  			break;
  		case 47:
  		case 1047:
  			window_pane_alternate_off(wp, &ictx->cell.cell, 0);
  			break;
  		case 1049:
  			window_pane_alternate_off(wp, &ictx->cell.cell, 1);
  			break;
  		case 2004:
  			screen_write_mode_clear(&ictx->ctx, MODE_BRACKETPASTE);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  	}
  }
  
  /* Handle CSI SM. */
  void
  input_csi_dispatch_sm(struct input_ctx *ictx)
  {
  	u_int	i;
  
  	for (i = 0; i < ictx->param_list_len; i++) {
  		switch (input_get(ictx, i, 0, -1)) {
  		case 4:		/* IRM */
  			screen_write_mode_set(&ictx->ctx, MODE_INSERT);
  			break;
  		case 34:
  			screen_write_mode_clear(&ictx->ctx, MODE_BLINKING);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  	}
  }
  
  /* Handle CSI private SM. */
  void
  input_csi_dispatch_sm_private(struct input_ctx *ictx)
  {
  	struct window_pane	*wp = ictx->wp;
  	u_int			 i;
  
  	for (i = 0; i < ictx->param_list_len; i++) {
  		switch (input_get(ictx, i, 0, -1)) {
  		case 1:		/* DECCKM */
  			screen_write_mode_set(&ictx->ctx, MODE_KCURSOR);
  			break;
  		case 3:		/* DECCOLM */
  			screen_write_cursormove(&ictx->ctx, 0, 0);
  			screen_write_clearscreen(&ictx->ctx);
  			break;
  		case 7:		/* DECAWM */
  			screen_write_mode_set(&ictx->ctx, MODE_WRAP);
  			break;
  		case 12:
  			screen_write_mode_set(&ictx->ctx, MODE_BLINKING);
  			break;
  		case 25:	/* TCEM */
  			screen_write_mode_set(&ictx->ctx, MODE_CURSOR);
  			break;
  		case 1000:
  			screen_write_mode_clear(&ictx->ctx, ALL_MOUSE_MODES);
  			screen_write_mode_set(&ictx->ctx, MODE_MOUSE_STANDARD);
  			break;
  		case 1002:
  			screen_write_mode_clear(&ictx->ctx, ALL_MOUSE_MODES);
  			screen_write_mode_set(&ictx->ctx, MODE_MOUSE_BUTTON);
  			break;
  		case 1004:
  			if (ictx->ctx.s->mode & MODE_FOCUSON)
  				break;
  			screen_write_mode_set(&ictx->ctx, MODE_FOCUSON);
  			wp->flags |= PANE_FOCUSPUSH; /* force update */
  			break;
  		case 1005:
  			screen_write_mode_set(&ictx->ctx, MODE_MOUSE_UTF8);
  			break;
  		case 1006:
  			screen_write_mode_set(&ictx->ctx, MODE_MOUSE_SGR);
  			break;
  		case 47:
  		case 1047:
  			window_pane_alternate_on(wp, &ictx->cell.cell, 0);
  			break;
  		case 1049:
  			window_pane_alternate_on(wp, &ictx->cell.cell, 1);
  			break;
  		case 2004:
  			screen_write_mode_set(&ictx->ctx, MODE_BRACKETPASTE);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  	}
  }
  
  /* Handle CSI window operations. */
  void
  input_csi_dispatch_winops(struct input_ctx *ictx)
  {
  	struct window_pane	*wp = ictx->wp;
  	int			 n, m;
  
  	m = 0;
  	while ((n = input_get(ictx, m, 0, -1)) != -1) {
  		switch (n) {
  		case 1:
  		case 2:
  		case 5:
  		case 6:
  		case 7:
  		case 11:
  		case 13:
  		case 14:
  		case 19:
  		case 20:
  		case 21:
  		case 24:
  			break;
  		case 3:
  		case 4:
  		case 8:
  			m++;
  			if (input_get(ictx, m, 0, -1) == -1)
  				return;
  			/* FALLTHROUGH */
  		case 9:
  		case 10:
  		case 22:
  		case 23:
  			m++;
  			if (input_get(ictx, m, 0, -1) == -1)
  				return;
  			break;
  		case 18:
  			input_reply(ictx, "\033[8;%u;%ut", wp->sy, wp->sx);
  			break;
  		default:
  			log_debug("%s: unknown '%c'", __func__, ictx->ch);
  			break;
  		}
  		m++;
  	}
  }
  
  /* Handle CSI SGR for 256 colours. */
  void
  input_csi_dispatch_sgr_256(struct input_ctx *ictx, int fgbg, u_int *i)
  {
  	struct grid_cell	*gc = &ictx->cell.cell;
  	int			 c;
  
  	(*i)++;
  	c = input_get(ictx, *i, 0, -1);
  	if (c == -1) {
  		if (fgbg == 38) {
  			gc->flags &= ~GRID_FLAG_FG256;
  			gc->fg = 8;
  		} else if (fgbg == 48) {
  			gc->flags &= ~GRID_FLAG_BG256;
  			gc->bg = 8;
  		}
  	} else {
  		if (fgbg == 38) {
  			gc->flags |= GRID_FLAG_FG256;
  			gc->fg = c;
  		} else if (fgbg == 48) {
  			gc->flags |= GRID_FLAG_BG256;
  			gc->bg = c;
  		}
  	}
  }
  
  /* Handle CSI SGR for RGB colours. */
  void
  input_csi_dispatch_sgr_rgb(struct input_ctx *ictx, int fgbg, u_int *i)
  {
  	struct grid_cell	*gc = &ictx->cell.cell;
  	int			 c, r, g, b;
  
  	(*i)++;
  	r = input_get(ictx, *i, 0, -1);
  	if (r == -1 || r > 255)
  		return;
  	(*i)++;
  	g = input_get(ictx, *i, 0, -1);
  	if (g == -1 || g > 255)
  		return;
  	(*i)++;
  	b = input_get(ictx, *i, 0, -1);
  	if (b == -1 || b > 255)
  		return;
  
  	c = colour_find_rgb(r, g, b);
  	if (fgbg == 38) {
  		gc->flags |= GRID_FLAG_FG256;
  		gc->fg = c;
  	} else if (fgbg == 48) {
  		gc->flags |= GRID_FLAG_BG256;
  		gc->bg = c;
  	}
  }
  
  /* Handle CSI SGR. */
  void
  input_csi_dispatch_sgr(struct input_ctx *ictx)
  {
  	struct grid_cell	*gc = &ictx->cell.cell;
  	u_int			 i;
  	int			 n;
  
  	if (ictx->param_list_len == 0) {
  		memcpy(gc, &grid_default_cell, sizeof *gc);
  		return;
  	}
  
  	for (i = 0; i < ictx->param_list_len; i++) {
  		n = input_get(ictx, i, 0, 0);
  
  		if (n == 38 || n == 48) {
  			i++;
  			switch (input_get(ictx, i, 0, -1)) {
  			case 2:
  				input_csi_dispatch_sgr_rgb(ictx, n, &i);
  				break;
  			case 5:
  				input_csi_dispatch_sgr_256(ictx, n, &i);
  				break;
  			}
  			continue;
  		}
  
  		switch (n) {
  		case 0:
  		case 10:
  			memcpy(gc, &grid_default_cell, sizeof *gc);
  			break;
  		case 1:
  			gc->attr |= GRID_ATTR_BRIGHT;
  			break;
  		case 2:
  			gc->attr |= GRID_ATTR_DIM;
  			break;
  		case 3:
  			gc->attr |= GRID_ATTR_ITALICS;
  			break;
  		case 4:
  			gc->attr |= GRID_ATTR_UNDERSCORE;
  			break;
  		case 5:
  			gc->attr |= GRID_ATTR_BLINK;
  			break;
  		case 7:
  			gc->attr |= GRID_ATTR_REVERSE;
  			break;
  		case 8:
  			gc->attr |= GRID_ATTR_HIDDEN;
  			break;
  		case 22:
  			gc->attr &= ~(GRID_ATTR_BRIGHT|GRID_ATTR_DIM);
  			break;
  		case 23:
  			gc->attr &= ~GRID_ATTR_ITALICS;
  			break;
  		case 24:
  			gc->attr &= ~GRID_ATTR_UNDERSCORE;
  			break;
  		case 25:
  			gc->attr &= ~GRID_ATTR_BLINK;
  			break;
  		case 27:
  			gc->attr &= ~GRID_ATTR_REVERSE;
  			break;
  		case 30:
  		case 31:
  		case 32:
  		case 33:
  		case 34:
  		case 35:
  		case 36:
  		case 37:
  			gc->flags &= ~GRID_FLAG_FG256;
  			gc->fg = n - 30;
  			break;
  		case 39:
  			gc->flags &= ~GRID_FLAG_FG256;
  			gc->fg = 8;
  			break;
  		case 40:
  		case 41:
  		case 42:
  		case 43:
  		case 44:
  		case 45:
  		case 46:
  		case 47:
  			gc->flags &= ~GRID_FLAG_BG256;
  			gc->bg = n - 40;
  			break;
  		case 49:
  			gc->flags &= ~GRID_FLAG_BG256;
  			gc->bg = 8;
  			break;
  		case 90:
  		case 91:
  		case 92:
  		case 93:
  		case 94:
  		case 95:
  		case 96:
  		case 97:
  			gc->flags &= ~GRID_FLAG_FG256;
  			gc->fg = n;
  			break;
  		case 100:
  		case 101:
  		case 102:
  		case 103:
  		case 104:
  		case 105:
  		case 106:
  		case 107:
  			gc->flags &= ~GRID_FLAG_BG256;
  			gc->bg = n - 10;
  			break;
  		}
  	}
  }
  
  /* DCS terminator (ST) received. */
  int
  input_dcs_dispatch(struct input_ctx *ictx)
  {
  	const char	prefix[] = "tmux;";
  	const u_int	prefix_len = (sizeof prefix) - 1;
  
  	if (ictx->flags & INPUT_DISCARD)
  		return (0);
  
  	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
  
  	/* Check for tmux prefix. */
  	if (ictx->input_len >= prefix_len &&
  	    strncmp(ictx->input_buf, prefix, prefix_len) == 0) {
  		screen_write_rawstring(&ictx->ctx,
  		    ictx->input_buf + prefix_len, ictx->input_len - prefix_len);
  	}
  
  	return (0);
  }
  
  /* OSC string started. */
  void
  input_enter_osc(struct input_ctx *ictx)
  {
  	log_debug("%s", __func__);
  
  	input_clear(ictx);
  }
  
  /* OSC terminator (ST) received. */
  void
  input_exit_osc(struct input_ctx *ictx)
  {
  	u_char	*p = ictx->input_buf;
  	u_int	 option;
  
  	if (ictx->flags & INPUT_DISCARD)
  		return;
  	if (ictx->input_len < 1 || *p < '0' || *p > '9')
  		return;
  
  	log_debug("%s: \"%s\"", __func__, p);
  
  	option = 0;
  	while (*p >= '0' && *p <= '9')
  		option = option * 10 + *p++ - '0';
  	if (*p == ';')
  		p++;
  
  	switch (option) {
  	case 0:
  	case 2:
  		screen_set_title(ictx->ctx.s, p);
  		server_status_window(ictx->wp->window);
  		break;
  	case 12:
  		if (*p != '?') /* ? is colour request */
  			screen_set_cursor_colour(ictx->ctx.s, p);
  		break;
  	case 112:
  		if (*p == '\0') /* no arguments allowed */
  			screen_set_cursor_colour(ictx->ctx.s, "");
  		break;
  	default:
  		log_debug("%s: unknown '%u'", __func__, option);
  		break;
  	}
  }
  
  /* APC string started. */
  void
  input_enter_apc(struct input_ctx *ictx)
  {
  	log_debug("%s", __func__);
  
  	input_clear(ictx);
  }
  
  /* APC terminator (ST) received. */
  void
  input_exit_apc(struct input_ctx *ictx)
  {
  	if (ictx->flags & INPUT_DISCARD)
  		return;
  	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
  
  	screen_set_title(ictx->ctx.s, ictx->input_buf);
  	server_status_window(ictx->wp->window);
  }
  
  /* Rename string started. */
  void
  input_enter_rename(struct input_ctx *ictx)
  {
  	log_debug("%s", __func__);
  
  	input_clear(ictx);
  }
  
  /* Rename terminator (ST) received. */
  void
  input_exit_rename(struct input_ctx *ictx)
  {
  	if (ictx->flags & INPUT_DISCARD)
  		return;
  	if (!options_get_number(&ictx->wp->window->options, "allow-rename"))
  		return;
  	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
  
  	window_set_name(ictx->wp->window, ictx->input_buf);
  	options_set_number(&ictx->wp->window->options, "automatic-rename", 0);
  
  	server_status_window(ictx->wp->window);
  }
  
  /* Open UTF-8 character. */
  int
  input_utf8_open(struct input_ctx *ictx)
  {
  	if (!options_get_number(&ictx->wp->window->options, "utf8")) {
  		/* Print, and do not switch state. */
  		input_print(ictx);
  		return (-1);
  	}
  	log_debug("%s", __func__);
  
  	utf8_open(&ictx->utf8data, ictx->ch);
  	return (0);
  }
  
  /* Append to UTF-8 character. */
  int
  input_utf8_add(struct input_ctx *ictx)
  {
  	log_debug("%s", __func__);
  
  	utf8_append(&ictx->utf8data, ictx->ch);
  	return (0);
  }
  
  /* Close UTF-8 string. */
  int
  input_utf8_close(struct input_ctx *ictx)
  {
  	log_debug("%s", __func__);
  
  	utf8_append(&ictx->utf8data, ictx->ch);
  
  	grid_cell_set(&ictx->cell.cell, &ictx->utf8data);
  	screen_write_cell(&ictx->ctx, &ictx->cell.cell);
  
  	return (0);
  }
  