Difference between revisions of "Dbnkey()"
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| Line 11: | Line 11: | ||
<input parameter> | <input parameter> | ||
| − | char *ndx; /* .NDX file descriptor | + | char *ndx; /* .NDX file descriptor */ |
<output parameters> | <output parameters> | ||
| − | char *key; /* Address of a buffer where key is stored by the function */ | + | char *key; /* Address of a buffer where key is stored by the function */ |
| − | long *recno; /* Address of a variable where the record number is stored by the function */ | + | long *recno; /* Address of a variable where the record number is stored by the function */ |
</code> | </code> | ||
| Line 37: | Line 37: | ||
#include "dbl.h" | #include "dbl.h" | ||
| − | char *ndx; /* .NDX file descriptor */ | + | char *ndx; /* .NDX file descriptor */ |
| − | char nextkey[10][8]; /* Keys buffer | + | char nextkey[10][8]; /* Keys buffer */ |
| − | long recno[10]; | + | long recno[10]; /* Record numbers buffer */ |
| − | int it; | + | int it; /* Loop control variable */ |
| − | int rc; | + | int rc; /* Return code */ |
for (i = 0; i < 10; ++i) | for (i = 0; i < 10; ++i) | ||
| − | if (dbnkey(ndx, &nextkey | + | if (dbnkey(ndx, &nextkey[i],&recno[i]) != SUCCESS) |
return(ERROR); | return(ERROR); | ||
Latest revision as of 13:52, 1 May 2009
PURPOSE
read next key
SYNOPSIS
#include "dbl.h" int dbnkey(ndx, key, recno) <input parameter> char *ndx; /* .NDX file descriptor */ <output parameters> char *key; /* Address of a buffer where key is stored by the function */ long *recno; /* Address of a variable where the record number is stored by the function */
RETURN VALUE
The dbnkey() function returns 0 for success, or < 0 if an error occurs. See the section on return code values for a detailed list of return codes.
DESCRIPTION
This function sequentially reads the next in ascending (or alphabetical) order and its corresponding record number from the specified .NDX file. If the function is called immediately after the file is open, it starts reading from the top of the file.
EXAMPLE
This example reads ten keys and their corresponding record numbers from the .NDX file whose file descriptor is specified in "char *ndx" and stores the keys and record numbers in "char nextkey[10][8]" and "long recno[10]" respectively. Keys are assumed to be numeric or date.
#include "dbl.h" char *ndx; /* .NDX file descriptor */ char nextkey[10][8]; /* Keys buffer */ long recno[10]; /* Record numbers buffer */ int it; /* Loop control variable */ int rc; /* Return code */ for (i = 0; i < 10; ++i) if (dbnkey(ndx, &nextkey[i],&recno[i]) != SUCCESS) return(ERROR);
