usr/src/games/adventure/save.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * The game adventure was original written Fortran by Will Crowther
 * and Don Woods.  It was later translated to C and enhanced by
 * Jim Gillogly.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)save.c      5.1 (Berkeley) %G%";
#endif /* not lint */

/* save (III)   J. Gillogly
 * save user core image for restarting
 * usage: save(<command file (argv[0] from main)>,<output file>)
 * bugs
 *   -  impure code (i.e. changes in instructions) is not handled
 *      (but people that do that get what they deserve)
 */

#include <sys/file.h>
#include <a.out.h>
int filesize;                    /* accessible to caller         */

char *sbrk();

save(cmdfile,outfile)                   /* save core image              */
char *cmdfile,*outfile;
{       register char *c;
        register int i,fd;
        int fdaout;
        struct exec header;
        int counter;
        char buff[512],pwbuf[120];
        fdaout = open(cmdfile, O_RDONLY, 0);    /* open command */
        if (fdaout<0) return(-1);       /* can do nothing without text  */
        if ((fd=creat(outfile,0755))== -1)
        {       printf("Cannot create %s\n",outfile);
                return(-1);
        }
        /* can get the text segment from the command that we were
         * called with, and change all data from uninitialized to
         * initialized.  It will start at the top again, so the user
         * is responsible for checking whether it was restarted
         * could ignore sbrks and breaks for the first pass
         */
        read(fdaout,&header,sizeof header);/* get the header       */
        header.a_bss = 0;                  /* no data uninitialized        */
        header.a_syms = 0;                 /* throw away symbol table      */
        switch (header.a_magic)            /* find data segment            */
        {   case 0407:                     /* non sharable code            */
                c = (char *) header.a_text;/* data starts right after text */
                header.a_data=sbrk(0)-c;   /* current size (incl allocs)   */
                break;
            case 0410:                     /* sharable code                */
                c = (char *)
#ifdef pdp11
                    (header.a_text         /* starts after text            */
                    & 0160000)             /* on an 8K boundary            */
                    +  020000;             /* i.e. the next one up         */
#endif
#ifdef vax
                    (header.a_text         /* starts after text            */
                    & 037777776000)        /* on an 1K boundary            */
                    +        02000;        /* i.e. the next one up         */
#endif
#ifdef tahoe
                    (header.a_text         /* starts after text            */
                    & 037777776000)        /* on an 1K boundary            */
                    +        02000;        /* i.e. the next one up         */
#endif
#ifdef z8000
                    (header.a_text         /* starts after text            */
                    & 0174000)             /* on an 2K boundary            */
                    +  004000;             /* i.e. the next one up         */
#endif
                header.a_data=sbrk(0)-c;   /* current size (incl allocs)   */
                break;
            case 0411:                     /* sharable with split i/d      */
                c = 0;                     /* can't reach text             */
                header.a_data=(int)sbrk(0);/* current size (incl allocs)   */
                break;
            case 0413:
                c = (char *) header.a_text;/* starts after text            */
                lseek(fdaout, 1024L, 0);   /* skip unused part of 1st block*/
        }
        if (header.a_data<0)               /* data area very big           */
                return(-1);                /* fail for now                 */

        filesize=sizeof header+header.a_text+header.a_data;
        write(fd,&header,sizeof header);   /* make the new header          */
        if (header.a_magic==0413)
                lseek(fd, 1024L, 0);       /* Start on 1K boundary         */
        counter=header.a_text;             /* size of text                 */
        while (counter>512)                /* copy 512-byte blocks         */
        {       read(fdaout,buff,512);     /* as long as possible          */
                write(fd,buff,512);
                counter -= 512;
        }
        read(fdaout,buff,counter);         /* then pick up the rest        */
        write(fd,buff,counter);
        write(fd,c,header.a_data);         /* write all data in 1 glob     */
        close(fd);
}