twaites@sicom.UUCP (Greg Twaites) (05/29/87)
Here is the C code that allows you to read a DBASE-III file. I verified
that it works under Microsoft C v4.0. Hope it does every thing you need.
I am not sure where it came from, so hopefully I am not violating anyones
copyrights :-). Have fun.
Greg Twaites
SICOM Inc.
!ihnp4!sun!sunburn!sicom!twaites
--------------------------------------------------------------------------
/*
* These functions are used to read dbase files.
*
* These functions are provided by Valour Software as a gift.
*
* The program is for test purposes only. No warranty is expressed nor
* implied. USE AT YOUR OWN RISK!
*
*
*/
#include <fcntl.h>
#include <sys\types.h>
#include <sys\stat.h>
#include <io.h>
#include <malloc.h>
typedef struct dbase_head {
unsigned char version; /*03 for dbIII and 83 for dbIII w/memo file*/
unsigned char l_update[3]; /*yymmdd for last update*/
unsigned long count; /*number of records in file*/
unsigned int header; /*length of the header
*includes the \r at end
*/
unsigned int lrecl; /*length of a record
*includes the delete
*byte
*/
unsigned char reserv[20];
} DBASE_HEAD;
typedef struct dbase_fld {
char name[11]; /*field name*/
char type; /*field type*/
#define DB_FLD_CHAR 'C'
#define DB_FLD_NUM 'N'
#define DB_FLD_LOGIC 'L'
#define DB_FLD_MEMO 'M'
#define DB_FLD_DATE 'D'
/* A-T uses large data model but drop it for now */
char far *data_ptr; /*pointer into buffer*/
unsigned char length; /*field length*/
unsigned char dec_point; /*field decimal point*/
unsigned char fill[14];
} DBASE_FIELD;
typedef struct fld_list {
struct fld_list *next;
DBASE_FIELD *fld;
char *data;
} FLD_LIST;
DBASE_HEAD dbhead={0};
FLD_LIST *db_fld_root=0;
char *Buffer;
char buf_work[255];
int dbfile;
/*------------------------------------------------------------code-------*/
main(argc,argv)
int argc;
char *argv[];
{
if(argc!=2)
error("Usage is db_dump filename.dbf");
dbfile=open(argv[1],O_RDONLY);
if(dbfile==-1)
error("Unable to open file");
db3_read_dic();
db3_print_recs(5);
printf("\n\n\t\t\tProcessing complete");
close(dbfile);
exit(0);
}
/******************************************************
db3_read_dic()
This function is called with a file name to
read to create a record type to support the
dbase file
******************************************************/
db3_read_dic()
{
int fields;
DBASE_FIELD *fld;
if(dbfile==-1) {
printf("open failed");
exit(200);
}
read(dbfile,&dbhead,sizeof(DBASE_HEAD));
if( !(dbhead.version==3 || dbhead.version==0x83) )
error("\n\aVersion %d not supported",dbhead.version);
printf("update year %3d\n",dbhead.l_update[0]);
printf("update mon %3d\n",dbhead.l_update[1]);
printf("update day %3d\n",dbhead.l_update[2]);
printf("number of recs %3d\n",dbhead.count);
printf("header length %3d\n",dbhead.header);
printf("record length %3d\n",dbhead.lrecl);
Buffer=malloc(dbhead.lrecl);
fields=(dbhead.header-1)/32-1;
printf("\nField Name\tType\tLength\tDecimal Pos\n");
while(fields--) {
fld=(DBASE_FIELD *)malloc(sizeof(DBASE_FIELD));
if(!fld)
error("\n\aNot enough memory\n");
read(dbfile,fld,sizeof(DBASE_FIELD));
printf("%-10s\t %c\t %3d\t %3d\n",fld->name,fld->type,
fld->length,fld->dec_point);
stack_field(fld);
}
read(dbfile,Buffer,1); /*read the silly little \r character*/
return;
}
/******************************************************
db3_print_recs()
Read records and print the data
******************************************************/
db3_print_recs(cnt)
int cnt;
{
int bytes;
while(cnt) {
bytes=read(dbfile,Buffer,dbhead.lrecl);
if(bytes!=dbhead.lrecl)
break;
if(Buffer[0]!='*') {
db3_print();
cnt--;
}
}
return;
}
/******************************************************
db3_print()
Print a single record
******************************************************/
db3_print()
{
FLD_LIST *list, *temp;
temp=db_fld_root;
printf("\n");
while(temp) {
memcpy(buf_work,temp->data,temp->fld->length);
buf_work[temp->fld->length]='\0';
printf("%-10s=%s\n",temp->fld->name,buf_work);
temp=temp->next;
}
return;
}
/******************************************************
stack_field()
Add a field to the linked list of fields
******************************************************/
stack_field(fld)
DBASE_FIELD *fld;
{
FLD_LIST *list, *temp;
list=(FLD_LIST *)calloc(1,sizeof(FLD_LIST));
if(!list)
error("\n\aNot enough memory\n");
list->fld=fld;
if(!db_fld_root) {
list->data=Buffer+1; /*skip delete byte*/
db_fld_root=list;
return;
}
temp=db_fld_root;
while(temp->next)
temp=temp->next;
temp->next=list;
list->data=temp->data + temp->fld->length;
return;
}
/******************************************************
error()
Produce error msg and abort
******************************************************/
error(msg)
char *msg;
{
printf(msg);
close(dbfile);
exit(255);
}