qdos.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 2004-May-22 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, both of these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/*
 * Yes this  file is necessary; the QDOS file system is the most
 * ludicrous known to man (even more so than VMS!).
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>

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

#ifdef QDOS

# include <qdos.h>

#if CRYPT

char *getp(m, p, n)
    ZCONST char *m;              /* prompt for password */
    char *p;                    /* return value: line input */
    int n;                      /* bytes available in p[] */
{
    int c;                      /* one-byte buffer for read() to use */
    int i;                      /* number of characters input */
    char *w;                    /* warning on retry */

    /* get password */
    w = "";
    sd_cure(getchid(0), -1);    /* enable cursor */
    do {
        fputs(w, stderr);       /* warning if back again */
        fputs(m, stderr);       /* display prompt and flush */
        fflush(stderr);
        i = 0;
        do {
            c = getch();
            if (c == 0xc2) {
                if (i > 0) {
                    i--; /* the `del' keys works */
                    fputs("\b \b", stderr);
                }
            }
            else if (i < n) {
                p[i++] = c;     /* truncate past n */
                if(c != '\n') putc('*', stderr);
            }
        } while (c != '\n');

        putc('\n', stderr);  fflush(stderr);
        w = "(line too long--try again)\n";
    } while (p[i-1] != '\n');

    p[i-1] = 0;                 /* terminate at newline */
    sd_curs(getchid(0), -1);    /* suppress cursor */
    return p;                   /* return pointer to password */

} /* end function getp() */

#endif /* CRYPT */


#define __attribute__(p)

int newname(char *, int, int);

#else /* !QDOS */
#define QDOS_FLMAX 36

short qlflag = 0;

struct qdirect  {
    long            d_length __attribute__ ((packed));  /* file length */
    unsigned char   d_access __attribute__ ((packed));  /* file access type */
    unsigned char   d_type __attribute__ ((packed));    /* file type */
    long            d_datalen __attribute__ ((packed)); /* data length */
    long            d_reserved __attribute__ ((packed));/* Unused */
    short           d_szname __attribute__ ((packed));  /* size of name */
    char            d_name[QDOS_FLMAX] __attribute__ ((packed));/* name area */
    long            d_update __attribute__ ((packed));  /* last update */
    long            d_refdate __attribute__ ((packed));
    long            d_backup __attribute__ ((packed));   /* EOD */
    } ;
#endif /* ?QDOS */

#define SHORTID 0x4afb          /* in big-endian order !! */
#define LONGID  "QDOS02"
#define EXTRALEN (sizeof(struct qdirect) + 8)

typedef struct
{
    unsigned short shortid __attribute__ ((packed));
    struct
    {
        unsigned char lo __attribute__ ((packed));
        unsigned char hi __attribute__ ((packed));
    } len __attribute__ ((packed));
    char        longid[8] __attribute__ ((packed));
    struct      qdirect     header __attribute__ ((packed));
} qdosextra;

#ifdef USE_EF_UT_TIME
local int GetExtraTime(struct zlist far *z, iztimes *z_utim, unsigned ut_flg);
#endif

#ifdef QDOS

#define rev_short(x) (x)
#define rev_long(x) (x)

char _prog_name[] = "zip";
char _copyright[] = "(c) Info-ZIP Group";
long _stack = 16*1024;
char *  _endmsg = NULL;

extern void consetup_title(chanid_t,struct WINDOWDEF *);
void (*_consetup)(chanid_t,struct WINDOWDEF *) = consetup_title;

struct WINDOWDEF _condetails =
{
    2,
    1,
    0,
    7,
    500,
    220,
    2,
    30
};

extern short qlwait;
extern short dtype;

#define CHECKDIR(p1) (((p1).d_type == dtype) && (((p1).d_length % 64) == 0))

char * stpcpy (char *d, ZCONST char *s)
{
    while(*d++ = *s++)
        ; /* Null loop */
    return d-1;
}

static jobid_t chowner(chanid_t chan)
{
    extern char *_sys_var;
    char *scht;
    long *cdb;
    long jid;

    scht = *((char **)(_sys_var + 0x78));
    cdb = *(long **)((long *)scht  + (chan & 0xffff));
    jid = *(cdb + 2);
    return jid;
}

void QDOSexit(void)
{
    jobid_t me,you;

    me = getpid();
    you = chowner(getchid(0));

    if((me == you) && ((qlflag & 4) == 0))
    {
        if(isatty(0) && isatty(2) && qlwait)
        {
            char c = 0;
            fputs("Press a key to exit", stderr);
            if((io_fbyte(getchid(0), qlwait, &c) == 0) && c == 27)
            {
                io_fbyte(getchid(0), -1, &c);
            }
        }
    }
    exit(ZE_OK);
}

/* Access seems to be *always* broken in c68 */
/* Not accurate, just works */

int access (char *f, int mode)
{
    struct stat st;
    int fd;

    if((fd = stat(f, &st)) == 0)
    {
        switch(fd)
        {
        case F_OK:
            break;
        case R_OK:
            fd = (st.st_mode & 0444) == 0;
            break;
        case W_OK:
            fd = (st.st_mode & 0222) == 0;
            break;
        case X_OK:
            fd = (st.st_mode & 0111) == 0;
            break;
        default:
            fd = -1;
            break;
        }
    }
    return fd;
}

/* Fixup a Mickey Mouse file naming system */

char * Unix2ql (char *qlname, char **dot)
{
    static char path[64];
    char name[64];
    char *q, *r, *s;

    strcpy(name, qlname);
    if(*name == '~')
    {
        r = name+1;
        getcwd(path, sizeof(path));
        q = path + strlen(path);
        if(*(q-1) != '_')
        {
            *q++ = '_';
        }
    }
    else
    {
        q = path;
        r = name;
    }

    if(*r == '/')
    {
        r++;
    }

    strcpy(q, r);

    while (*q)
    {
        if(*q == '/' || *q == '.')
        {
            if(*q == '.' && dot)
            {
                *dot = name + (q - path);
            }
            *q = '_';
        }

        q++;
    }
    return path;
}

#if 0                                 /* Not used in ZIP */

GuessAltName(char *name, char *dot)
{
    if(dot)
    {
        *dot = '.';
    }
    else
    {
        if((dot = strrchr(name, '_')))
        {
            *dot = '.';
        }
    }
}

#endif /* 0 */

short devlen(char *p)
{
    char defpath[40];
    short deflen = 0, ok = 0;

    getcwd(defpath, sizeof(defpath));
    deflen = strlen(defpath);
    if(deflen)
    {
        if(strnicmp(p, defpath, deflen) == 0)
        {
            ok = 1;
        }
    }

    if(!ok)
    {
        if(isdirdev(p))
        {
            deflen = 5;
        }
        else
        {
            deflen = 0;
        }
    }
    return deflen;
}

char * ql2Unix (char *qlname)
{
    struct stat st;
    int sts;
    char *p, *r, *s, *ldp;
    char *pnam = NULL;
    static char path[64];
    short  deflen;
    char name[64];

    strcpy(name, qlname);
    strcpy(path, name);

    deflen = devlen(qlname);

    p = name + deflen;
    pnam = path + deflen;

    if(s = strrchr(p, '_'))
    {
        *s = 0;
        sts = stat(name, &st);
        if(deflen && sts ==0 && (st.st_mode & S_IFDIR))
        {
            *(path+(s-name)) = '/';
        }
        else
        {
            *(path+(s-name)) = '.';
        }
    }

    ldp = p;
    for(r = p; *r; r++)
    {
        if(r != ldp && *r == '_')
        {
            *r = 0;
            if(deflen)
            {
                sts = stat(name, &st);
            }
            else
                sts = -1;

            if(sts ==0 && (st.st_mode & S_IFDIR))
            {
                *(path+(r-name)) = '/';
                ldp = r + 1;
            }
            else
            {
                *(path+(r-name)) = '_';
            }
            *r = '_';
        }
    }
    return pnam;
}

char *LastDir(char *ws)
{
    char *p;
    char *q = ws;
    struct stat s;

    for(p = ws; *p; p++)
    {
        if(p != ws && *p == '_')
        {
            char c;

            p++;
            c = *p;
            *p = 0;
            if(stat(ws, &s) == 0 && S_ISDIR(s.st_mode))
            {
                q = p;
            }
            *p = c;
        }
    }
    return q;
}

# ifndef UTIL

static int add_dir(char * dnam)
{
    int e = ZE_OK;
    char *p;
    short nlen;

    nlen = strlen(dnam);
    if(p = malloc(nlen + 2))
    {
        strncpy (p, dnam, nlen);
        if(*(p+nlen) != '_')
        {
            *(p+nlen) = '_';
            *(p+nlen+1) = '\0';
        }
        if ((e = newname(p, 1, 0)) != ZE_OK)
        {
                free(p);
        }
    }
    else
    {
        e = ZE_MEM;
    }
    return e;
}

int qlwild (char *dnam, short dorecurse, short l)
{
    static char match[40] = {0};
    static char ddev[8] =  {0};
    static short nc;
    static short llen;
    static char base[40];