Right now you're not freeing anything, which is... kind of okay... the same way its okay, if sloppy, to not close open files. It all goes away when the program ends anyway. But if you were doing that 10,000 times in a loop you'd be using 10,000 times as much memory which could definitely be a Bad Thing.
How to free it? As soon as you don't need any of that array anymore, do this:
I have a problem reading characters from keyboard with the scanf function.
Here there is a little piece of code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
/* The last 3 libraries are included because in the real program I use some... (4 Replies)
i have a function:
char *pcCityIdToCountryName(ADMIN_DB_DATA *pstHEader, unit uiCityID)
this returns a pointer to CountryName if cityId is given.
to retrieve countryname i give:
char *CountryName;
CountryName = pcCityIdToCountryName(..................);
but when i compile it is giving :... (5 Replies)
i am having a string like
" X1 " ---> string lenght is 30
I have stored this to a chararry . ref
so here ref = " X1 "
now i trim the left space by my function . Si the string now becomes
"X1 " ---> string lenght is 15... (3 Replies)
If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:
int my_malloc(int size, char **pmem)
{
*pmem=(char *)malloc(size);
if(*pmem==NULL)... (11 Replies)
hello all,
my question is not about How code can be rewritten, i just wanna know even though i am not using read only memory of C (i have declared str) why this function gives me segfault :wall:and the other code executes comfortably though both code uses same pointer arithmetic.
... (4 Replies)
Does anyone know?
int x = 1;
int *p = &++x; //ok !
int *q = &x++; //gives an error :O
why the first pointer is ok but the second is an error? (13 Replies)
I'm newbie learner. My all friend use windows just only me use linux.
so i can't solve any problem by myself. i need a solution.
how can i use pointer as a string.
#include<string.h>
#include<stdio.h>
int main()
{
char *s='\0';
gets(s);
puts(s);
return 0;
}
This code work on... (6 Replies)
Hello, I am trying to reverse complement one string and reverse another (NO complement!), both with pointer. My code compiled without error, but did not do the job I wanted.
#include <stdio.h>
#include <stdlib.h>
#include <zlib.h>
#include "kseq.h"
// STEP 1: declare the type of file... (5 Replies)
Discussion started by: yifangt
5 Replies
LEARN ABOUT SUNOS
index
index(3C) Standard C Library Functions index(3C)NAME
index, rindex - string operations
SYNOPSIS
#include <strings.h>
char *index(const char *s, int c);
char *rindex(const char *s, int c);
DESCRIPTION
The index() and rindex() functions operate on null-terminated strings.
The index() function returns a pointer to the first occurrence of character c in string s.
The rindex() function returns a pointer to the last occurrence of character c in string s.
Both index() and rindex() return a null pointer if c does not occur in the string. The null character terminating a string is considered
to be part of the string.
USAGE
On most modern computer systems, you can not use a null pointer to indicate a null string. A null pointer is an error and results in an
abort of the program. If you wish to indicate a null string, you must use a pointer that points to an explicit null string. On some
machines and with some implementations of the C programming language, a null pointer, if dereferenced, would yield a null string. Though
often used, this practice is not always portable. Programmers using a null pointer to represent an empty string should be aware of this
portability issue. Even on machines where dereferencing a null pointer does not cause an abort of the program, it does not necessarily
yield a null string.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
SEE ALSO bstring(3C), malloc(3C), string(3C), attributes(5), standards(5)SunOS 5.10 24 Jul 2002 index(3C)