ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/PROG/ASSEMBLY/OVL301.ZIP/MAPOVL.C

C/C++ Source or Header | 1989-02-02 | 4.6 KB | 143 lines

/* MAPOVL.C

    programmed in the small memory model of Turbo C version 2.0

    Show file information for overlays appended to a root .EXE file

*/

#include "stdio.h"
#include "dos.h"
#include "string.h"
#include "io.h"
#include "conio.h"
#include "stdlib.h"

FILE *fp;

char fname[128];
char f_noext_name[125];    /* file name in fname without extension */
unsigned char header[27];
char buff[8192];    /* file buffer for setvbuf */

unsigned int filecount=0;
unsigned long filelen;    /* length of .exe file (overlay or root) */
unsigned long len_no_hdr;    /* length of file without .exe header byte */
unsigned int relocation_count;    /* number of relocation table items */
unsigned long relocation_bytes;    /* byte count of relocation table items */
unsigned int header_size;    /* size of .exe header */
unsigned long ovl_largest=0L;    /* size of largest overlay file */
unsigned int which_ovl=0;    /* overlay file number that is largest */

void operate(),report();
int get_info();

void main(int argc, char *argv[])
{
    char *period_pos;    /* position of period in fname */
    char temp[180];

    if(argc<2){    /* file name was not provided on command line */
        cprintf("\n\rInput filename for report\r\n");
        gets(fname);
    }
    else{    /* command link provided file name */
        strcpy(fname,argv[1]);
    }
    strcpy(f_noext_name,fname);
    if((period_pos=strchr(f_noext_name,'.'))==NULL){    /* need to add default .exe file extension */
        strcat(fname,".exe");    /* add the .exe extension */
    }
    else{
        period_pos[0]=0;    /* kill the extension */
    }
    sprintf(temp,"Report on file %s",fname);
    printf("\n\n%s",temp);    /* print header */
    strset(temp,'=');    /* make a separation just as long as the header line */
    printf("\n%s",temp);    /* print separation line */
    operate();
}

void operate()
{
    int breakflag=0;

    if((fp=fopen(fname,"rb"))==NULL){    /* error opening file */
        printf("\n\007Error opening file %s\n",fname);
        exit(1);
    }
    setvbuf(fp,buff,_IOFBF,8192);    /* speed up i/o */
    while(!feof(fp)){    /* split out .exe files until end of file or invalid .exe information */
        breakflag=get_info();
        if(breakflag)    /* no more files, or error */
            break;
        report();
        filecount++;    /* increment count of overlay files */
    }
    if(ovl_largest>0){    /* only print if there is an overlay file */
        printf("\n\nOverlay file %d always loads into the standard overlay area.",
            which_ovl);
    }
    fclose(fp);

    printf("\n\nReport complete: %d overlay file%s\n",filecount-1,filecount!=2?"s":"");
}

int get_info()
{
    int signature,ovl_number;
    fread(header,27,1,fp);    /* read in first 27 .exe header bytes */
    fseek(fp,-27L,SEEK_CUR);    /* position back to start of .exe file */

    signature=(header[0]=='M' && header[1]=='Z');    /* check for valid MZ .exe signature */
    ovl_number=header[26];    /* get overlay number */
    if(!signature || ovl_number!=filecount){    /* header bytes have invalid values */
        return(1);    /* not a proper .exe file */
    }
    header[0]=header[1]=0;    /* force invalid signature if no more bytes to read */

    filelen=header[5];
    filelen*=256L;
    filelen+=header[4];    /* size of file in 512 byte pages */
    filelen*=512L;    /* get length of .exe file to nearest 512 byte page */

    header_size=header[9];
    header_size*=256;
    header_size+=header[8];    /* size of header in paragraphs */
    header_size*=16;    /* size of header in bytes */

    len_no_hdr=filelen-header_size;    /* size of file without any .exe header bytes (size of code) */

    relocation_count=header[7];
    relocation_count*=256;
    relocation_count+=header[6];    /* get number of relocation table items */

    relocation_bytes=(long)relocation_count*4L;    /* get byte count of relocation table items */

    fseek(fp,filelen,SEEK_CUR);    /* position to read info of next .exe file */

    return(0);    /* successful read of information */
}

void report()
{
    if(!filecount){    /* root file */
        printf("\n\nRoot file:  File size %6ld (%lx hex) bytes",len_no_hdr,len_no_hdr);
        printf("\n    Relocation table %5d (%x hex) items, %6ld (%lx hex) bytes",
            relocation_count,relocation_count,relocation_bytes,relocation_bytes);
        printf("\n    Unaffected by /ZBn option");
    }
    else{    /* overlay file */
        printf("\n\nOverlay file %2d:  File size %6ld (%lx hex) bytes",filecount,
            len_no_hdr,len_no_hdr);
        printf("\n    Relocation table %5d (%x hex) items, %6ld (%lx hex) bytes",
            relocation_count,relocation_count,relocation_bytes,relocation_bytes);
        printf("\n    /ZBn option requires 'n' of %d for no table reload",
            relocation_count==0?1:1+(int)((relocation_bytes-1)/1024));
        if(len_no_hdr>ovl_largest){    /* new largest overlay file */
            ovl_largest=len_no_hdr;
            which_ovl=filecount;
        }
    }
}