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Thanks Espen. I'll take a look at Boost.PropertyTree
I didn't get what you meant by
Espen Harlinn wrote: Normally you would create a class that is able to hold more than one configuration entry, and then something representing the various kinds of entries.
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Something structured somewhat like this:
class ConfigEntry
{
};
class ConfigNode : public ConfigEntry
{
typedef std::map<std::string,std::shared_ptr<ConfigEntry> > EntryMap;
EntryMap entryMap_;
};
class ConfigValue : public ConfigEntry
{
};
class StringConfigValue : public ConfigValue
{
std::string value_;
};
class IntConfigValue : public ConfigValue
{
int value_;
};
class ConfigFile : public ConfigNode
{
};
This way the EntryMap can hold std::string, int and nested ConfigNode objects.
Espen Harlinn
Chief Architect - Powel AS
Projects promoting programming in "natural language" are intrinsically doomed to fail. Edsger W.Dijkstra
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If you're using this in C++ only, seems ok (let alone the preferences).
However, I'd do this:
- no namespace exports; be wary of linker decorations
- export just the needed functions, not all (i.e. the "public" interface)
- separate helpers from actors (i.e openConfigFile, isDefined vs getBool, getInt)
- do not return std::string or others from functions; rather, return just simple testable values (int, bool) and change to
bool openConfigFile(const std::string& filename, std::string& result); (or std::string* result)
- if you'll get this used in other places, favor a C-like interface and do the plumbing code, such as
BOOL WINAPI OpenConfigFileA(LPCSTR fileName, LPSTR* result);
or use VARIANTs is needed in VBS.
- or favor the COM-like exports with just structs with virtual pure functions and DllGetClassObject-like creators.
There are many things to consider. I'm using sometimes even paper and pen to weight all these.
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Hi I am beginner in c++ , I have a console project and want to convert it to windows application , after 6-7 days trying I couldn't convert it and when I compile project I have many more errors
This is my console project: http:
Please convert it for me to windows gui application to help me thanks a lot
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Don't convert console apps, rather follow this short list:
1. Make sure key logic is not in same file as main.
2. Create a dialog app using Visual Studio
3. Add files from step 1
4. Hook up functionality
Of course 4 is the complicated part since how Windowed apps work is different from Console. As previously suggested, if you don't know how windowed apps work, get educated. Petzold isn't a bad starting point, though will only take you so far.
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Just another homework, no effort from poster, just "I can't do it" and a link.
We're supposed to invest time and effort to offer you solutions for free, in our time, so you can get an A and forget about C++ or something? RTFM.
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in this code?from where i need to understand that is deleting something?
void Database_delete(struct Connection *conn, int id)
{
struct Address addr = {.id = id, .set = 0};
conn->db->rows[id] = addr;
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As far as I know, this is not valid C++ code.
THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?!
-- C++ FQA Lite
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Yes, you are right. 
THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?!
-- C++ FQA Lite
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This[^] thread might help. It looks as though there are members of the Address struct one called set and it's getting initialized to 0, and another called id and it's getting initialized to the given integer id.
"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
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yes,but by the name of function says(database_delete),this function must delete something,and i don't know how it is deleting something
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Just a guess, perhaps set is some kind of flag marking a record as inactive or something, as opposed to actually deleting a record. What a functions name is and what it actually does may be two different things. What's needed here I believe is some useful comments.
"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
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can i give you the entire code?maybe you will find my answer
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This ties into the code you posted below. Specifically, it's related to this method:
void Database_set(struct Connection *conn, int id, const char *name, const char *email)
{
struct Address *addr = &conn->db->rows[id];
if(addr->set) die("Already set, delete it first");
addr->set = 1;Basically, it looks like it's controlling whether or not you've already set the value in this row - so, to set a value here, you would call Database_delete first, which changes the value in id from 1 to 0, which means that the rest of Database_set can continue.
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i understand now,thank you very much!
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You're welcome. 
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#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#define MAX_DATA 512
#define MAX_ROWS 100
struct Address {
int id;
int set;
char name[MAX_DATA];
char email[MAX_DATA];
};
struct Database {
struct Address rows[MAX_ROWS];
};
struct Connection {
FILE *file;
struct Database *db;
};
void die(const char *message)
{
if(errno) {
perror(message);
} else {
printf("ERROR: %s\n", message);
}
exit(1);
}
void Address_print(struct Address *addr)
{
printf("%d %s %s\n",
addr->id, addr->name, addr->email);
}
void Database_load(struct Connection *conn)
{
int rc = fread(conn->db, sizeof(struct Database), 1, conn->file);
if(rc != 1) die("Failed to load database.");
}
struct Connection *Database_open(const char *filename, char mode)
{
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error");
conn->db = malloc(sizeof(struct Database));
if(!conn->db) die("Memory error");
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if(conn->file) {
Database_load(conn);
}
}
if(!conn->file) die("Failed to open the file");
return conn;
}
void Database_close(struct Connection *conn)
{
if(conn) {
if(conn->file) fclose(conn->file);
if(conn->db) free(conn->db);
free(conn);
}
}
void Database_write(struct Connection *conn)
{
rewind(conn->file);
int rc = fwrite(conn->db, sizeof(struct Database), 1, conn->file);
if(rc != 1) die("Failed to write database.");
rc = fflush(conn->file);
if(rc == -1) die("Cannot flush database.");
}
void Database_create(struct Connection *conn)
{
int i = 0;
for(i = 0; i < MAX_ROWS; i++) {
// make a prototype to initialize it
struct Address addr = {.id = i, .set = 0};
// then just assign it
conn->db->rows[i] = addr;
}
}
void Database_set(struct Connection *conn, int id, const char *name, const char *email)
{
struct Address *addr = &conn->db->rows[id];
if(addr->set) die("Already set, delete it first");
addr->set = 1;
// WARNING: bug, read the "How To Break It" and fix this
char *res = strncpy(addr->name, name, MAX_DATA);
// demonstrate the strncpy bug
if(!res) die("Name copy failed");
res = strncpy(addr->email, email, MAX_DATA);
if(!res) die("Email copy failed");
}
void Database_get(struct Connection *conn, int id)
{
struct Address *addr = &conn->db->rows[id];
if(addr->set) {
Address_print(addr);
} else {
die("ID is not set");
}
}
void Database_delete(struct Connection *conn, int id)
{
struct Address addr = {.id = id, .set = 0};
conn->db->rows[id] = addr;
}
void Database_list(struct Connection *conn)
{
int i = 0;
struct Database *db = conn->db;
for(i = 0; i < MAX_ROWS; i++) {
struct Address *cur = &db->rows[i];
if(cur->set) {
Address_print(cur);
}
}
}
int main(int argc, char *argv[])
{
if(argc < 3) die("USAGE: ex17 <dbfile> <action> [action params]");
char *filename = argv[1];
char action = argv[2][0];
struct Connection *conn = Database_open(filename, action);
int id = 0;
if(argc > 3) id = atoi(argv[3]);
if(id >= MAX_ROWS) die("There's not that many records.");
switch(action) {
case 'c':
Database_create(conn);
Database_write(conn);
break;
case 'g':
if(argc != 4) die("Need an id to get");
Database_get(conn, id);
break;
case 's':
if(argc != 6) die("Need id, name, email to set");
Database_set(conn, id, argv[4], argv[5]);
Database_write(conn);
break;
case 'd':
if(argc != 4) die("Need id to delete");
Database_delete(conn, id);
Database_write(conn);
break;
case 'l':
Database_list(conn);
break;
default:
die("Invalid action, only: c=create, g=get, s=set, d=del, l=list");
}
Database_close(conn);
return 0;
}
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Alex Sturza wrote: Database_close(conn);
return 0;
}
Are you sure that is your question?
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my bad,sry about you wasted time to read my code )
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Just try reading things a bit before posting here. Your other question (in the C# forum) is similar.
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Can you not search this code yourself?  Database_close() is called right before main() returns.
In the future, please post only relevant code snippets.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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omg,sry about that badd miss,and thanks anyway!
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Hi,
Is there any way to convert WMI Win32_OperatingSystem InstallDate to mm/dd/yyyy format in C++. I have seen there is a class defined in C# for the same. But I didn't find anything in C++.
When I run WMI query "Select InstallDate from Win32_Operating system", I get : 20120714160600.000000+330 as the result.
I want to convert this to some readable format e:g: dd/mm/yyyy format with time also.
Anybody have any idea about this.?
Regards,
Mbatra
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