return textstring ??

Hi

Is it possible to return a textstring.
ex: I need to return the time in a program.
But if I put the time in a textsting, how can I return it, so I can
call the function gettime() from another program??

tx
------------------------ex: code

int gettime()
{
struct time t;
gettime(&t);
printf("The current time is: %2d:%02d:%02d\n",
t.ti_hour, t.ti_min, t.ti_sec);

return ??;

}

A quick and dirty way of returning strings is to put the burden of memory management on the recepient. Caller will have to free() the memory it receives.

Code:

char *gettime()
{
  struct time t;
  gettime(&t);
  char *pc = (char *)malloc(1024);
  sprintf(pc, "The current time is: %2d:%02d:%02d\n", t.ti_hour, t.ti_min,  t.ti_sec);

  return pc;
}

Something like that (allocation can be done in a better way);

What you will want to do is return a char*, so it would look like this:

Code:

char* GetTime() 
{ 
    char *Time = malloc(sizeof(char)*256);
    struct time t; 
    gettime(&t); 
    snprintf(Time, 256, "The current time is: %2d:%02d:%02d\n", t.ti_hour, t.ti_min, t.ti_sec); 

return Time; 
}

What it does is create a char* called Time. Time is created with a size of 256. snprintf stores the message like printf into a string (Time). Then the time is returned. You could call GetTime() like this:

Code:

char* CurrentTime;
CurrentTime = GetTime();
//Later in your program you need to free CurrentTime
free(CurrentTime);

- Sean

tx for your reply, but the error message is as follows:

Cannot convert 'void *' to 'char *'


char* gettime()
{
char *Time = malloc(sizeof(char)*256); /* this line ??*/
struct time t;
gettime(&t);
sprintf(Time,"The current time is: %2d:%02d:%02d\n", t.ti_hour, t.ti_min, t.ti_sec);
return Time;
}

int freeAllocated()
{
char* CurrentTime;
CurrentTime = gettime();
free(CurrentTime);
return 0;
}


int main()
{
gettime();
getch();
freeAllocated();
getch();
return 0;
}

>Cannot convert 'void *' to 'char *'
You're probably compiling this code as C++.

-Prelude

Howcome it dosn't work in C++.?

C++ has a much stronger type checking than C, so you have to cast the return of malloc before assigning it. This is one of the places where perfectly valid and correct C code will not compile as C++.

-Prelude

Now it seems to work , but not text is comming up.

Is the something missing.
Here is the whole test code:

---------code clip

#include <stdio.h>
#include <conio.h>
#include <alloc.h>
#include <dos.h>
char* GetTheTime(void);
int freeAllocated(void);

char* GetTheTime()
{
char *Time = malloc(sizeof(char)*256);
struct time t;
gettime(&t);

sprintf(Time,"The current time is: %2d:%02d:%02d\n", t.ti_hour, t.ti_min, t.ti_sec);
return Time;
}

int freeAllocated()
{
char* CurrentTime;
CurrentTime = GetTheTime();
free(CurrentTime);
return 0;
}


int main()
{

GetTheTime();
getch();
freeAllocated();*/

getch();
return 0;
}

I figured it all out.
Tx a lot for all your help...