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Gibberish returned when trying to return a char pointer

Posted on 2011-02-24
2
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Last Modified: 2012-06-22
Hello,

This code:
char *GetID()
{
	FILE * pFile;
  long lSize;
  char * buffer;
  size_t result;

  pFile = fopen ( "c:\\program files\\example\\example.log" , "rb" );
  if (pFile==NULL) {fputs ("File error",stderr); exit (1);}

  fseek (pFile , 0 , SEEK_END);
  lSize = ftell (pFile);
  rewind (pFile);

  buffer = (char*) malloc (sizeof(char)*lSize);
  if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);}

  result = fread (buffer,1,lSize,pFile);
//  buffer[lSize] = { '\n' };
  if (result != lSize) {fputs ("Reading error",stderr); exit (3);}

  fclose (pFile);
  char * pch;
//  char * nonNull;
  char finalsid[256] = {' \0 '};
  int i = 0;
  char  finalbuff[256] = { '\0' };
  if(strstr(buffer, "0:1:") == NULL && strstr(buffer, "0:0:") == NULL)
  {
	  puts("Not Installed");
	  exit(0);
  }
  if(strstr (buffer,"0:1:") == NULL)
  {
	pch = strstr (buffer,"0:0:");
  }
	else{
	  if(strstr(buffer, "0:0:") == NULL)
	  {
	pch = strstr (buffer,"0:1:");
	  }
  }


  for(i = 0; i < 256; ++i)
  {

	if(pch[i] == '\n')
	{
		
		strncpy((char*)finalbuff, (const char*)finalsid, strlen(finalsid) -1);
		
		break;

	}
	else
	{
		strncat((char *)finalsid, (const char*)pch + i, 1);
		
	}

  }
 
  return finalbuff;

}

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when I call for this function from main as so:
int main()
{
char *result;
result = GetID();
return 0;
}

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"result" is all gibberish, even though "finalbuff" that is being returned isn't.

So basically I need to know how to return a char pointer properly

Thanks!
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Question by:JoeD77
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2 Comments
 
LVL 10

Accepted Solution

by:
peetm earned 500 total points
ID: 34972408
Aren't you effectively returning a pointer to a local variable.  Make finalbuff static as a quick sanity check.
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Author Comment

by:JoeD77
ID: 34972445
ha that fixed it. Thanks!
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