ttyio.c

给出了 zip 压缩算法的完整实现过程。

/*
  Copyright (c) 1990-2005 Info-ZIP.  All rights reserved.

  See the accompanying file LICENSE, version 2005-Feb-10 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, all these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/*---------------------------------------------------------------------------

  ttyio.c

  This file contains routines for doing console input/output, including code
  for non-echoing input.  It is used by the encryption/decryption code but
  does not contain any restricted code itself.  This file is shared between
  Info-ZIP's Zip and UnZip.

  Contains:  echo()         (VMS only)
             Echon()        (Unix only)
             Echoff()       (Unix only)
             screensize()   (Unix only)
             zgetch()       (Unix, VMS, and non-Unix/VMS versions)
             getp()         ("PC," Unix/Atari/Be, VMS/VMCMS/MVS)

  ---------------------------------------------------------------------------*/

#define __TTYIO_C       /* identifies this source module */

#include "zip.h"
#include "crypt.h"

#if (CRYPT || (defined(UNZIP) && !defined(FUNZIP)))
/* Non-echo console/keyboard input is needed for (en/de)cryption's password
 * entry, and for UnZip(SFX)'s MORE and Pause features.
 * (The corresponding #endif is found at the end of this module.)
 */

#include "ttyio.h"

#ifndef PUTC
#  define PUTC putc
#endif

#ifdef ZIP
#  ifdef GLOBAL          /* used in Amiga system headers, maybe others too */
#    undef GLOBAL
#  endif
#  define GLOBAL(g) g
#else
#  define GLOBAL(g) G.g
#endif

#if (defined(__ATHEOS__) || defined(__BEOS__))  /* why yes, we do */
#  define HAVE_TERMIOS_H
#endif

#ifdef _POSIX_VERSION
#  ifndef USE_POSIX_TERMIOS
#    define USE_POSIX_TERMIOS  /* use POSIX style termio (termios) */
#  endif
#  ifndef HAVE_TERMIOS_H
#    define HAVE_TERMIOS_H     /* POSIX termios.h */
#  endif
#endif /* _POSIX_VERSION */

#ifdef UNZIP            /* Zip handles this with the unix/configure script */
#  ifndef _POSIX_VERSION
#    if (defined(SYSV) || defined(CRAY)) &&  !defined(__MINT__)
#      ifndef USE_SYSV_TERMIO
#        define USE_SYSV_TERMIO
#      endif
#      ifdef COHERENT
#        ifndef HAVE_TERMIO_H
#          define HAVE_TERMIO_H
#        endif
#        ifdef HAVE_SYS_TERMIO_H
#          undef HAVE_SYS_TERMIO_H
#        endif
#      else /* !COHERENT */
#        ifdef HAVE_TERMIO_H
#          undef HAVE_TERMIO_H
#        endif
#        ifndef HAVE_SYS_TERMIO_H
#           define HAVE_SYS_TERMIO_H
#        endif
#      endif /* ?COHERENT */
#    endif /* (SYSV || CRAY) && !__MINT__ */
#  endif /* !_POSIX_VERSION */
#  if !(defined(BSD4_4) || defined(SYSV) || defined(__convexc__))
#    ifndef NO_FCNTL_H
#      define NO_FCNTL_H
#    endif
#  endif /* !(BSD4_4 || SYSV || __convexc__) */
#endif /* UNZIP */

#ifdef HAVE_TERMIOS_H
#  ifndef USE_POSIX_TERMIOS
#    define USE_POSIX_TERMIOS
#  endif
#endif

#if (defined(HAVE_TERMIO_H) || defined(HAVE_SYS_TERMIO_H))
#  ifndef USE_SYSV_TERMIO
#    define USE_SYSV_TERMIO
#  endif
#endif

#if (defined(UNZIP) && !defined(FUNZIP) && defined(UNIX) && defined(MORE))
#  include <sys/ioctl.h>
#  define GOT_IOCTL_H
   /* int ioctl OF((int, int, zvoid *));   GRR: may need for some systems */
#endif

#ifndef HAVE_WORKING_GETCH
   /* include system support for switching of console echo */
#  ifdef VMS
#    include <descrip.h>
#    include <iodef.h>
#    include <ttdef.h>
#    include <starlet.h>
#    include <ssdef.h>
#  else /* !VMS */
#    ifdef HAVE_TERMIOS_H
#      include <termios.h>
#      define sgttyb termios
#      define sg_flags c_lflag
#      define GTTY(f, s) tcgetattr(f, (zvoid *) s)
#      define STTY(f, s) tcsetattr(f, TCSAFLUSH, (zvoid *) s)
#    else /* !HAVE_TERMIOS_H */
#      ifdef USE_SYSV_TERMIO           /* Amdahl, Cray, all SysV? */
#        ifdef HAVE_TERMIO_H
#          include <termio.h>
#        endif
#        ifdef HAVE_SYS_TERMIO_H
#          include <sys/termio.h>
#        endif
#        ifdef NEED_PTEM
#          include <sys/stream.h>
#          include <sys/ptem.h>
#        endif
#        define sgttyb termio
#        define sg_flags c_lflag
#        define GTTY(f,s) ioctl(f,TCGETA,(zvoid *)s)
#        define STTY(f,s) ioctl(f,TCSETAW,(zvoid *)s)
#      else /* !USE_SYSV_TERMIO */
#        ifndef CMS_MVS
#          if (!defined(MINIX) && !defined(GOT_IOCTL_H))
#            include <sys/ioctl.h>
#          endif
#          include <sgtty.h>
#          define GTTY gtty
#          define STTY stty
#          ifdef UNZIP
             /*
              * XXX : Are these declarations needed at all ????
              */
             /*
              * GRR: let's find out...   Hmmm, appears not...
             int gtty OF((int, struct sgttyb *));
             int stty OF((int, struct sgttyb *));
              */
#          endif
#        endif /* !CMS_MVS */
#      endif /* ?USE_SYSV_TERMIO */
#    endif /* ?HAVE_TERMIOS_H */
#    ifndef NO_FCNTL_H
#      ifndef UNZIP
#        include <fcntl.h>
#      endif
#    else
       char *ttyname OF((int));
#    endif
#  endif /* ?VMS */
#endif /* !HAVE_WORKING_GETCH */



#ifndef HAVE_WORKING_GETCH
#ifdef VMS

static struct dsc$descriptor_s DevDesc =
        {11, DSC$K_DTYPE_T, DSC$K_CLASS_S, "SYS$COMMAND"};
     /* {dsc$w_length, dsc$b_dtype, dsc$b_class, dsc$a_pointer}; */

/*
 * Turn keyboard echoing on or off (VMS).  Loosely based on VMSmunch.c
 * and hence on Joe Meadows' file.c code.
 */
int echo(opt)
    int opt;
{
    /*
     * For VMS v5.x:
     *   IO$_SENSEMODE/SETMODE info:  Programming, Vol. 7A, System Programming,
     *     I/O User's: Part I, sec. 8.4.1.1, 8.4.3, 8.4.5, 8.6
     *   sys$assign(), sys$qio() info:  Programming, Vol. 4B, System Services,
     *     System Services Reference Manual, pp. sys-23, sys-379
     *   fixed-length descriptor info:  Programming, Vol. 3, System Services,
     *     Intro to System Routines, sec. 2.9.2
     * Greg Roelofs, 15 Aug 91
     */

    short           DevChan, iosb[4];
    long            status;
    unsigned long   ttmode[2];  /* space for 8 bytes */


    /* assign a channel to standard input */
    status = sys$assign(&DevDesc, &DevChan, 0, 0);
    if (!(status & 1))
        return status;

    /* use sys$qio and the IO$_SENSEMODE function to determine the current
     * tty status (for password reading, could use IO$_READVBLK function
     * instead, but echo on/off will be more general)
     */
    status = sys$qiow(0, DevChan, IO$_SENSEMODE, &iosb, 0, 0,
                     ttmode, 8, 0, 0, 0, 0);
    if (!(status & 1))
        return status;
    status = iosb[0];
    if (!(status & 1))
        return status;

    /* modify mode buffer to be either NOECHO or ECHO
     * (depending on function argument opt)
     */
    if (opt == 0)   /* off */
        ttmode[1] |= TT$M_NOECHO;                       /* set NOECHO bit */
    else
        ttmode[1] &= ~((unsigned long) TT$M_NOECHO);    /* clear NOECHO bit */

    /* use the IO$_SETMODE function to change the tty status */
    status = sys$qiow(0, DevChan, IO$_SETMODE, &iosb, 0, 0,
                     ttmode, 8, 0, 0, 0, 0);
    if (!(status & 1))
        return status;
    status = iosb[0];
    if (!(status & 1))
        return status;

    /* deassign the sys$input channel by way of clean-up */
    status = sys$dassgn(DevChan);
    if (!(status & 1))
        return status;

    return SS$_NORMAL;   /* we be happy */

} /* end function echo() */


/*
 * Read a single character from keyboard in non-echoing mode (VMS).
 * (returns EOF in case of errors)
 */
int tt_getch()
{
    short           DevChan, iosb[4];
    long            status;
    char            kbbuf[16];  /* input buffer with - some - excess length */

    /* assign a channel to standard input */
    status = sys$assign(&DevDesc, &DevChan, 0, 0);
    if (!(status & 1))
        return EOF;

    /* read a single character from SYS$COMMAND (no-echo) and
     * wait for completion
     */
    status = sys$qiow(0,DevChan,
                      IO$_READVBLK|IO$M_NOECHO|IO$M_NOFILTR,
                      &iosb, 0, 0,
                      &kbbuf, 1, 0, 0, 0, 0);
    if ((status&1) == 1)
        status = iosb[0];

    /* deassign the sys$input channel by way of clean-up
     * (for this step, we do not need to check the completion status)
     */
    sys$dassgn(DevChan);

    /* return the first char read, or EOF in case the read request failed */
    return (int)(((status&1) == 1) ? (uch)kbbuf[0] : EOF);

} /* end function tt_getch() */


#else /* !VMS:  basically Unix */


/* For VM/CMS and MVS, non-echo terminal input is not (yet?) supported. */
#ifndef CMS_MVS

#ifdef ZIP                      /* moved to globals.h for UnZip */
   static int echofd=(-1);      /* file descriptor whose echo is off */
#endif

/*
 * Turn echo off for file descriptor f.  Assumes that f is a tty device.
 */
void Echoff(__G__ f)
    __GDEF
    int f;                    /* file descriptor for which to turn echo off */
{
    struct sgttyb sg;         /* tty device structure */

    GLOBAL(echofd) = f;
    GTTY(f, &sg);             /* get settings */
    sg.sg_flags &= ~ECHO;     /* turn echo off */
    STTY(f, &sg);
}

/*
 * Turn echo back on for file descriptor echofd.
 */
void Echon(__G)
    __GDEF
{
    struct sgttyb sg;         /* tty device structure */

    if (GLOBAL(echofd) != -1) {
        GTTY(GLOBAL(echofd), &sg);    /* get settings */
        sg.sg_flags |= ECHO;  /* turn echo on */
        STTY(GLOBAL(echofd), &sg);
        GLOBAL(echofd) = -1;
    }
}

#endif /* !CMS_MVS */
#endif /* ?VMS */


#if (defined(UNZIP) && !defined(FUNZIP))

#ifdef ATH_BEO_UNX
#ifdef MORE

/*
 * Get the number of lines on the output terminal.  SCO Unix apparently
 * defines TIOCGWINSZ but doesn't support it (!M_UNIX).
 *
 * GRR:  will need to know width of terminal someday, too, to account for
 *       line-wrapping.
 */

#if (defined(TIOCGWINSZ) && !defined(M_UNIX))

int screensize(tt_rows, tt_cols)
    int *tt_rows;
    int *tt_cols;
{