Difference between revisions of "Dbxopen()"
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<input parameters> | <input parameters> | ||
| − | char *dbf; | + | char *dbf; /* .DBF file descriptor */ |
| − | char *filename; /* Address of a buffer containing the name of a .DBX file to be opened */ | + | char *filename; /* Address of a buffer containing the name of a .DBX file to be opened */ |
<output parameters> | <output parameters> | ||
| − | char *dbx; /* The .DBX file descriptor | + | char *dbx; /* The .DBX file descriptor */ |
</code> | </code> | ||
| Line 23: | Line 23: | ||
The dbxopen() function returns 0 for success , or < 0 if an error occurs. See the section on [[Library Return Code Values|return code values]] for a detailed list of return codes. | The dbxopen() function returns 0 for success , or < 0 if an error occurs. See the section on [[Library Return Code Values|return code values]] for a detailed list of return codes. | ||
| + | |||
==DESCRIPTION== | ==DESCRIPTION== | ||
This function opens a .DBX file and returns its file descriptor. A call to The dbxclose() function releases the file descriptor. | This function opens a .DBX file and returns its file descriptor. A call to The dbxclose() function releases the file descriptor. | ||
| − | |||
| Line 38: | Line 38: | ||
<code lang="c"> | <code lang="c"> | ||
#include <stdio.h> | #include <stdio.h> | ||
| − | #include "dbl.h" | + | #include "dbl.h" /* Recital/Library include file */ |
| − | #include "dblproto.h" /* Recital/Library prototype file */ | + | #include "dblproto.h" /* Recital/Library prototype file */ |
static dBFIELD fields[6] = { | static dBFIELD fields[6] = { | ||
| Line 55: | Line 55: | ||
int rc); | int rc); | ||
| − | main() | + | main() |
| − | { | + | { |
| − | + | int rc; /* Return Code for error handling */ | |
| − | + | char *dbf; /* File descriptor for table */ | |
| − | + | char *dbx; /* File descriptor for tagged index */ | |
| − | + | char keytype; /* Variable for varying keytype */ | |
| − | + | char tagname[21]; /* Storage location for tag name */ | |
| − | + | char keyexpr[512]; /* Storage location for key expr */ | |
| − | + | char forexpr[512]; /* Storage location for for expr */ | |
| − | + | int kexprlen; /* The key expression length */ | |
| − | + | int keylen; /* The key length */ | |
| − | + | int i; /* Loop control variable */ | |
| − | + | int keyunique; /* Boolean for unqiue tag key */ | |
| − | + | int keydescend; /* Boolean for descending tag key */ | |
| − | + | int notags; /* Number of tags in a dbx file */ | |
| − | + | rc = dbdcache(100); | |
| − | + | errorproc("dbdcache()","table cache specified.", rc); | |
| − | + | rc = dbicache(100); | |
| − | + | errorproc("dbicache()", "index cache specified.",rc); | |
| − | + | rc = dbfilemode(0,0); | |
| − | + | rc = dbopen("shipwreck.dbf", &dbf); | |
| − | + | errorproc("dbopen()","table opened in exclusive mode.", rc); | |
| − | + | rc = dbxopen(dbf, "shipwreck.dbx", &dbx); | |
| − | + | errorproc("dbxopen()","tagged index opened.", rc); | |
| − | + | rc = dbxnotags(dbx, ¬ags); | |
| − | + | errorproc("dbxnotags()","tagged index count obtained.", rc); | |
| − | + | printf("\t Key count: \t%d\n", notags ); | |
| − | + | for (i = 1; i <= notags; i++) { | |
| − | + | rc = dbxkexpr(dbx, | |
&i, | &i, | ||
tagname, | tagname, | ||
| Line 95: | Line 95: | ||
&keyunique, | &keyunique, | ||
&keydescend); | &keydescend); | ||
| − | + | errorproc("dbxkexpr()", "key information retrieved.", rc); | |
| − | + | printf("\t Key number: \t%d\n", i ); | |
| − | + | printf("\t Key name: \t%s\n", tagname ); | |
| − | + | printf("\t Key type: \t%c\n", keytype ); | |
| − | + | printf("\t Key expression: %s\n", keyexpr); | |
| − | + | printf("\t Key length: %d Expression length: %d\n", kexprlen, keylen); | |
| − | + | printf("\t For expression: %s\n", forexpr); | |
| − | + | printf("\t Key unique: \t%s\n", keyunique ? "Yes" : "No" ); | |
| − | + | printf("\t Key descending: \t%s\n", keydescend?"Yes":"No" ); | |
| − | + | } | |
| − | + | rc = dbxclose(dbx); | |
| − | + | errorproc("dbxclose()", "tagged index closed.", rc); | |
| − | + | rc = dbclose(dbf); | |
| − | + | errorproc("dbclose()", "table closed.", rc); | |
| − | + | exit(0); | |
| − | } | + | } |
static void errorproc(func, str, rc) | static void errorproc(func, str, rc) | ||
| Line 117: | Line 117: | ||
char *str; | char *str; | ||
int rc; | int rc; | ||
| − | { | + | { |
| − | + | if ( rc != SUCCESS ) { | |
| − | + | printf("\n Error performing function %s -> %d\n", func, rc); | |
| − | + | exit(1); | |
} | } | ||
| − | printf("Function: t%s, t%s - | + | printf("Function: \t%s, \t%s - Ok\n", func, str); |
return; | return; | ||
} | } | ||
Latest revision as of 16:25, 5 May 2009
PURPOSE
open a .dbx index file
SYNOPSIS
#include "dbl.h" int dbxopen(dbf, filename, dbx); <input parameters> char *dbf; /* .DBF file descriptor */ char *filename; /* Address of a buffer containing the name of a .DBX file to be opened */ <output parameters> char *dbx; /* The .DBX file descriptor */
RETURN VALUE
The dbxopen() 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 opens a .DBX file and returns its file descriptor. A call to The dbxclose() function releases the file descriptor.
EXAMPLE
The following example opens the index for the shipwreck.dbf table, checks the number of tags, then returns detailed information about the tags
#include <stdio.h> #include "dbl.h" /* Recital/Library include file */ #include "dblproto.h" /* Recital/Library prototype file */ static dBFIELD fields[6] = { "VESSEL", 'C', 18, 0, 0, "LAT", 'N', 4, 1, 0, "LONG", 'N', 4, 1, 0, "AMOUNT", 'N', 10, 0, 0, "DATE", 'D', 8, 0, 0, "FLAG", 'C', 9, 0, 0 }; static void errorproc( char *func, char *str, int rc); main() { int rc; /* Return Code for error handling */ char *dbf; /* File descriptor for table */ char *dbx; /* File descriptor for tagged index */ char keytype; /* Variable for varying keytype */ char tagname[21]; /* Storage location for tag name */ char keyexpr[512]; /* Storage location for key expr */ char forexpr[512]; /* Storage location for for expr */ int kexprlen; /* The key expression length */ int keylen; /* The key length */ int i; /* Loop control variable */ int keyunique; /* Boolean for unqiue tag key */ int keydescend; /* Boolean for descending tag key */ int notags; /* Number of tags in a dbx file */ rc = dbdcache(100); errorproc("dbdcache()","table cache specified.", rc); rc = dbicache(100); errorproc("dbicache()", "index cache specified.",rc); rc = dbfilemode(0,0); rc = dbopen("shipwreck.dbf", &dbf); errorproc("dbopen()","table opened in exclusive mode.", rc); rc = dbxopen(dbf, "shipwreck.dbx", &dbx); errorproc("dbxopen()","tagged index opened.", rc); rc = dbxnotags(dbx, ¬ags); errorproc("dbxnotags()","tagged index count obtained.", rc); printf("\t Key count: \t%d\n", notags ); for (i = 1; i <= notags; i++) { rc = dbxkexpr(dbx, &i, tagname, &keytype, keyexpr, forexpr, &kexprlen, &keylen, &keyunique, &keydescend); errorproc("dbxkexpr()", "key information retrieved.", rc); printf("\t Key number: \t%d\n", i ); printf("\t Key name: \t%s\n", tagname ); printf("\t Key type: \t%c\n", keytype ); printf("\t Key expression: %s\n", keyexpr); printf("\t Key length: %d Expression length: %d\n", kexprlen, keylen); printf("\t For expression: %s\n", forexpr); printf("\t Key unique: \t%s\n", keyunique ? "Yes" : "No" ); printf("\t Key descending: \t%s\n", keydescend?"Yes":"No" ); } rc = dbxclose(dbx); errorproc("dbxclose()", "tagged index closed.", rc); rc = dbclose(dbf); errorproc("dbclose()", "table closed.", rc); exit(0); } static void errorproc(func, str, rc) char *func; char *str; int rc; { if ( rc != SUCCESS ) { printf("\n Error performing function %s -> %d\n", func, rc); exit(1); } printf("Function: \t%s, \t%s - Ok\n", func, str); return; }
