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The database() function includes a loop that asks if you want to add a new record, delete an existing record, or quit. The other functions implement various data management functions: datadd(), transkey(), getfld(), and datdel().
Below is the code for the "Manage" functions, database(), datadd(), transkey(), getfld(), and datdel():
/********************************************************
* *
* database: This is the main action function. *
* *
********************************************************/
#ifdef PROTOTYPE
VOID database(void)
#else
VOID database()
#endif
{
TEXT choice[2];
#ifdef PROTOTYPE
VOID datadd(void), datdel(void);
#else
VOID datadd(), datdel();
#endif
choice[0] = '\0';
while (choice[0] != 'Q')
{
printf("\n\nA)dd D)elete Q)uit:");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
if (!ctrt_fgets(inpbuf, sizeof(inpbuf), stdin))
inpbuf[0] = 'Q';
choice[0] = (TEXT)toupper((NINT)inpbuf[0]);
switch (choice[0])
{
case 'A':
datadd(); /* add new entry to database */
break;
case 'D':
datdel(); /* delete existing entries */
break;
default:
break;
} /* end switch */
} /* end while */
}
/********************************************************
* *
* dataadd: Add a new record *
* *
********************************************************/
#ifdef PROTOTYPE
VOID datadd(void)
#else
VOID datadd()
#endif
{
printf("\nADD NEW DATA\n\n");
/* Initialize the new record so that all fields are blank */
invent.delete_flag[0] = '\0';
invent.delete_flag[1] = '\0';
invent.item[0] = '\0';
invent.descrip[0] = '\0';
invent.location[0] = '\0';
invent.quantity = 0.0;
invent.cost = 0.0;
getfld(); /* acquire new item info */
transkey(keyfld,invent.item,sizeof(invent.item)); /* prepare key for use */
/* Look to see if this key is already *
* in the file. */
if (GetKey(INVENTIDX,keyfld))
{
printf("\nKey already in file, cannot add");
return;
}
if (uerr_cod) /* Check for error in EQLKEY call*/
{
func_error(INVENTIDX);
return;
}
/* Get data record from data file */
if ((datarec = NewData(INVENTDAT)) == 0)
/* assignment intended */
{
func_error(INVENTDAT);
return;
}
/* Write data record to data file */
if (WriteData(INVENTDAT,datarec,&invent))
{
func_error(INVENTDAT);
ReleaseData(INVENTDAT,datarec);
/* if we cannot write to *
* the record, we will *
* return the record to *
* the pool. */
LockCtData(INVENTDAT,ctFREE,datarec);
/* NewData puts a lock on *
* the record automatically*
* that we must free */
return;
}
/* Add key to the index, now that we know*
* that we have successfully added the *
* record to the data file. */
if (AddKey(INVENTIDX,keyfld,datarec,REGADD))
{
func_error(INVENTIDX);
ReleaseData(INVENTDAT,datarec);
/* If cannot add key, *
* then return the record.*/
LockCtData(INVENTDAT,ctFREE,datarec);
/* NewData puts a lock on *
* the record automatically*
* that we must free */
return;
}
printf("\nSuccessful Addition");
LockCtData(INVENTDAT,ctFREE,datarec);
/* release the lock that NewData placed*/
return;
}
/**********************************************************
* *
* transkey: The key field must be properly formatted *
* by us, as c-tree does not format it *
* automatically with low level functions. *
* We are going to do two things to the *
* key. First, we will translate all of the *
* alpha characters to upper case. Second, *
* we will pad the key to its full length. *
* This second part is very critical! c-tree *
* looks at the entire buffer when comparing *
* keys, and if you have garbage after a *
* null terminated string in a key buffer, *
* that becomes a part of the key! *
* *
***********************************************************/
#ifdef PROTOTYPE
VOID transkey(pTEXT dest,pTEXT source,NINT len)
#else
VOID transkey(dest,source,len)
pTEXT dest,source;
NINT len;
#endif
{
TEXT ch;
len--;
/* loop until field filled or null found,
* translating any lower case to upper case */
while(*source && len-- > 0)
{
ch = *source++;
*dest++ = (TEXT)toupper((NINT)ch);
}
/* fill the rest of the field with nulls, if needed */
while(len-- > 0)
*dest++ = '\0';
*dest = '\0';
}
/********************************************************
* *
* getfld: enter input information *
* *
********************************************************/
#ifdef PROTOTYPE
VOID getfld(void)
#else
VOID getfld()
#endif
{
printf("\nEnter Item ID: ");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
if (inpbuf[0] != '\0')
cpybuf(invent.item,inpbuf,sizeof(invent.item));
printf("\nEnter Description: ");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
if (inpbuf[0] != '\0')
cpybuf(invent.descrip,inpbuf,sizeof(invent.descrip));
printf("\nEnter Location: ");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
if (inpbuf[0] != '\0')
cpybuf(invent.location,inpbuf,sizeof(invent.location));
printf("\nEnter Quantity: ");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
if (inpbuf[0] != '\0')
sscanf(inpbuf,"%lf",&invent.quantity);
printf("\nEnter Cost: ");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
if (inpbuf[0] != '\0')
sscanf(inpbuf,"%lf",&invent.cost);
}
/********************************************************
* *
* datdel: find and delete record *
* *
********************************************************/
#ifdef PROTOTYPE
VOID datdel(void)
#else
VOID datdel()
#endif
{
printf("\nDELETE DATA\n");
printf("\nEnter Item to Delete:");
fflush(stdout);
ctsfill(inpbuf,0,INPBUFSIZ);
ctrt_fgets(inpbuf, sizeof(inpbuf), stdin);
transkey(keyfld,inpbuf,sizeof(invent.item));
/* Prepare key for use. It is important to form
* this key in the same way as we do keys to be added,
* since we will be looking for an exact match
*/
/* find the key to delete in index */
if (!(datarec = GetKey(INVENTIDX,keyfld)))
{
if (uerr_cod)
func_error(INVENTIDX);
else
printf("\nKey not found");
return;
}
/* read the record to display */
if (ReadData(INVENTDAT,datarec,&invent))
func_error(INVENTDAT);
else
{
printf("\n\nItem %s",invent.item);
printf("\nDescription %s",invent.descrip);
printf("\nLocation %s",invent.location);
printf("\nQuantity %f",invent.quantity);
printf("\nCost %f",invent.cost);
}
/* Delete the key from index */
if (DeleteKey(INVENTIDX,keyfld,datarec))
{
printf("\n\nKey delete failed (code %d).",uerr_cod);
return;
}
/* Return the data record to pool */
if (ReleaseData(INVENTDAT,datarec))
printf("\n\nData record delete failed (code %d).",uerr_cod);
else
printf("\n\nDelete Successful");
}
