BSD 4_1_snap release

[unix-history] / usr / src / cmd / px / int.c

/* Copyright (c) 1979 Regents of the University of California */

static char sccsid[] = "@(#)int.c 1.4 6/21/81";

/*
* px - interpreter for Berkeley Pascal
* Version 3.0 Winter 1979
*
* Original version for the PDP 11/70 authored by:
* Bill Joy, Charles Haley, Ken Thompson
*
* Rewritten for VAX 11/780 by Kirk McKusick
*/

#include        <signal.h>
#include        "whoami.h"
#include        "vars.h"
#include        "objfmt.h"

main(ac,av)

       int     ac;
       char    **av;

{
       register char *objprog, *file;
       register long bytesread, bytestoread, block;
       register FILE *prog;
       struct   pxhdr pxhd;
#       define   pipe 3

       /*
        * Initialize everything
        */
       _argc = ac;
       _argv = av;
       _nodump = FALSE;
\f
       /*
        * Determine how PX was invoked, and how to process the program 
        */
       if (_argv[0][0] == '-' && _argv[0][1] == 'o') {
               file = &_argv[0][2];
               _mode = PIX;
       } else if (_argc <= 1) {
               file = "obj";
               _mode = PX;
       } else if (_argv[1][0] != '-') {
               file = _argv[1];
               _mode = PX;
       } else if (_argv[1][1] == 0) {
               file = _argv[0];
               _mode = PIPE;
               _argc -= 1;
               _argv[1] = _argv[0];
               _argv = &_argv[1];
       } else {
               fputs("Improper specification of object file to PX\n",stderr);
               exit(1);
       }
\f
       /*
        * Process program header information
        */
       if (_mode == PIPE) {
               read(pipe,&pxhd,sizeof(struct pxhdr));
       } else {
               prog = fopen(file,"r");
               if (prog == NULL) {
                       perror(file);
                       exit(1);
               }
               fseek(prog,(long)(HEADER_BYTES-sizeof(struct pxhdr)),0);
               fread(&pxhd,sizeof(struct pxhdr),1,prog);
       }
       if (pxhd.maketime < createtime) {
               fprintf(stderr,"%s is obsolete and must be recompiled\n",file);
               exit(1);
       }
       if (pxhd.magicnum != MAGICNUM) {
               fprintf(stderr,"%s is not a Pascal interpreter file\n",file);
               exit(1);
       }
\f
       /*
        * Load program into memory
        */
       objprog = malloc((int)pxhd.objsize);
       if (_mode == PIPE) {
               bytestoread = pxhd.objsize;
               bytesread = 0;
               do      {
                       block = read(pipe,(int)(objprog+bytesread),bytestoread);
                       if (block > 0) {
                               bytesread += block;
                               bytestoread -= block;
                       }
               } while (block > 0);
       } else {
               bytesread = fread(objprog,1,(int)pxhd.objsize,prog);
               fclose(prog);
               if (_mode == PIX)
                       unlink(file);
       }
       if (bytesread != pxhd.objsize) {
               fprintf(stderr,"Read error occurred while loading %s\n",file);
               exit(1);
       }
       if (_mode == PIX)
               fputs("Execution begins...\n",stderr);
       /*
        * set interpreter to catch expected signals and begin interpretation
        */
       signal(SIGILL,syserr);
       signal(SIGBUS,syserr);
       signal(SIGSYS,syserr);
       if (signal(SIGINT,SIG_IGN) != SIG_IGN)
               signal(SIGINT,intr);
       signal(SIGSEGV,memsize);
       signal(SIGFPE,except);
       signal(SIGTRAP,liberr);
       /*
        * do it
        */
       interpreter(objprog);
       /*
        * reset signals, deallocate memory, and exit normally
        */
       signal(SIGINT,SIG_IGN);
       signal(SIGSEGV,SIG_DFL);
       signal(SIGFPE,SIG_DFL);
       signal(SIGTRAP,SIG_DFL);
       signal(SIGILL,SIG_DFL);
       signal(SIGBUS,SIG_DFL);
       signal(SIGSYS,SIG_DFL);
       PFLUSH();
       /* pfree(objprog); */
       psexit(0);
}