tty.h

一个简单的操作系统minix的核心代码

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				src/kernel/tty.h	 	 
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11600	/*      tty.h - Terminals       */
11601	
11602	#define TTY_IN_BYTES     256    /* tty input queue size */
11603	#define TAB_SIZE           8    /* distance between tab stops */
11604	#define TAB_MASK           7    /* mask to compute a tab stop position */
11605	
11606	#define ESC             '\33'   /* escape */
11607	
11608	#define O_NOCTTY       00400    /* from <fcntl.h>, or cc will choke */
11609	#define O_NONBLOCK     04000
11610	
11611	typedef _PROTOTYPE( void (*devfun_t), (struct tty *tp) );
11612	typedef _PROTOTYPE( void (*devfunarg_t), (struct tty *tp, int c) );
11613	
11614	typedef struct tty {
11615	  int tty_events;               /* set when TTY should inspect this line */
11616	
11617	  /* Input queue.  Typed characters are stored here until read by a program. */
11618	  u16_t *tty_inhead;            /* pointer to place where next char goes */
11619	  u16_t *tty_intail;            /* pointer to next char to be given to prog */
11620	  int tty_incount;              /* # chars in the input queue */
11621	  int tty_eotct;                /* number of "line breaks" in input queue */
11622	  devfun_t tty_devread;         /* routine to read from low level buffers */
11623	  devfun_t tty_icancel;         /* cancel any device input */
11624	  int tty_min;                  /* minimum requested #chars in input queue */
11625	  clock_t tty_time;             /* time when the input is available */
11626	  struct tty *tty_timenext;     /* for a list of ttys with active timers */
11627	
11628	  /* Output section. */
11629	  devfun_t tty_devwrite;        /* routine to start actual device output */
11630	  devfunarg_t tty_echo;         /* routine to echo characters input */
11631	  devfun_t tty_ocancel;         /* cancel any ongoing device output */
11632	  devfun_t tty_break;           /* let the device send a break */
11633	
11634	  /* Terminal parameters and status. */
11635	  int tty_position;             /* current position on the screen for echoing */
11636	  char tty_reprint;             /* 1 when echoed input messed up, else 0 */
11637	  char tty_escaped;             /* 1 when LNEXT (^V) just seen, else 0 */
11638	  char tty_inhibited;           /* 1 when STOP (^S) just seen (stops output) */
11639	  char tty_pgrp;                /* slot number of controlling process */
11640	  char tty_openct;              /* count of number of opens of this tty */
11641	
11642	  /* Information about incomplete I/O requests is stored here. */
11643	  char tty_inrepcode;           /* reply code, TASK_REPLY or REVIVE */
11644	  char tty_incaller;            /* process that made the call (usually FS) */
11645	  char tty_inproc;              /* process that wants to read from tty */
11646	  vir_bytes tty_in_vir;         /* virtual address where data is to go */
11647	  int tty_inleft;               /* how many chars are still needed */
11648	  int tty_incum;                /* # chars input so far */
11649	  char tty_outrepcode;          /* reply code, TASK_REPLY or REVIVE */
11650	  char tty_outcaller;           /* process that made the call (usually FS) */
11651	  char tty_outproc;             /* process that wants to write to tty */
11652	  vir_bytes tty_out_vir;        /* virtual address where data comes from */
11653	  int tty_outleft;              /* # chars yet to be output */
11654	  int tty_outcum;               /* # chars output so far */
11655	  char tty_iocaller;            /* process that made the call (usually FS) */
11656	  char tty_ioproc;              /* process that wants to do an ioctl */
11657	  int tty_ioreq;                /* ioctl request code */
11658	  vir_bytes tty_iovir;          /* virtual address of ioctl buffer */
11659	
11660	  /* Miscellaneous. */
11661	  devfun_t tty_ioctl;           /* set line speed, etc. at the device level */
11662	  devfun_t tty_close;           /* tell the device that the tty is closed */
11663	  void *tty_priv;               /* pointer to per device private data */
11664	  struct termios tty_termios;   /* terminal attributes */
11665	  struct winsize tty_winsize;   /* window size (#lines and #columns) */
11666	
11667	  u16_t tty_inbuf[TTY_IN_BYTES];/* tty input buffer */
11668	} tty_t;
11669	
11670	EXTERN tty_t tty_table[NR_CONS+NR_RS_LINES+NR_PTYS];
11671	
11672	/* Values for the fields. */
11673	#define NOT_ESCAPED        0    /* previous character is not LNEXT (^V) */
11674	#define ESCAPED            1    /* previous character was LNEXT (^V) */
11675	#define RUNNING            0    /* no STOP (^S) has been typed to stop output */
11676	#define STOPPED            1    /* STOP (^S) has been typed to stop output */
11677	
11678	/* Fields and flags on characters in the input queue. */
11679	#define IN_CHAR       0x00FF    /* low 8 bits are the character itself */
11680	#define IN_LEN        0x0F00    /* length of char if it has been echoed */
11681	#define IN_LSHIFT          8    /* length = (c & IN_LEN) >> IN_LSHIFT */
11682	#define IN_EOT        0x1000    /* char is a line break (^D, LF) */
11683	#define IN_EOF        0x2000    /* char is EOF (^D), do not return to user */
11684	#define IN_ESC        0x4000    /* escaped by LNEXT (^V), no interpretation */
11685	
11686	/* Times and timeouts. */
11687	#define TIME_NEVER      ((clock_t) -1 < 0 ? (clock_t) LONG_MAX : (clock_t) -1)
11688	#define force_timeout() ((void) (tty_timeout = 0))
11689	
11690	EXTERN tty_t *tty_timelist;     /* list of ttys with active timers */
11691	
11692	/* Number of elements and limit of a buffer. */
11693	#define buflen(buf)     (sizeof(buf) / sizeof((buf)[0]))
11694	#define bufend(buf)     ((buf) + buflen(buf))