how to check if something exists in a struct linked list?
can someone provide an example of a struct linked list, where it has strings as its values, and then how do I check if a specific string (say called buffer) exists in the list of structs?
i dont understand how to make a copy of it to check with
this is what i have
Code:
// CHECK IF ITEM EXISTS IN THE ITEM LIST
check=0; tmp_item_list=item_list;
while(tmp_item_list) {
if (strcmp(tmp_item_list->number,buffer)==0) {
tmp_buffer0[0]='\0';
strcat(tmp_buffer0,tmp_item_list->number);
strcat(tmp_buffer0," ");
strcat(tmp_buffer0,tmp_item_list->name);
strcat(tmp_buffer0," ");
strcat(tmp_buffer0,tmp_item_list->current_price);
strcat(tmp_buffer0,"\n");
send_message(i, tmp_buffer0); check=1; break;
}
tmp_item_list=tmp_item_list->next;
}
i want to make a copy because if i dont then
tmp_item_list=tmp_item_list->next;
will screw it up
also this wont work, because somehow when i iterate through the list, it seems the list repeats again...
this compiles fine with no errors/warnings
---------- Post updated at 10:13 PM ---------- Previous update was at 09:00 PM ----------
Suppose to have:
struct Tstudent
{
string name, surname;
int matriculation_num;
};
struct Tnode
{
Tstudent* student;
Tnodo* next;
} L;I want to deference that "student" pointer. For example, I tried with:
*(L->student).matriculation_numbut it not worked, as terminal... (4 Replies)
i have a linked list set up like
typedef struct client_list {
char *client_name;
int client_socket_fd;
struct client_list *next;
} client;
client *client_list=NULL;
before adding to the list i check if it already exists, only if it does not then i add
if (client_list==NULL... (1 Reply)
Hi,
I have received an application that stores some properties in a file. The existing struct looks like this:
struct TData
{
UINT uSizeIncludingStrings;
// copy of Telnet data struct
UINT uSize;
// basic properties:
TCHAR szHost; //defined in Sshconfig
UINT iPortNr;
TCHAR... (2 Replies)
Hi
#Testing for file existence
if ; then
echo 'SCHOOL data is available for processing'
else
echo 'SCHOOL DATA IS NOT AVAILABLE FOR PROCESSING'
:
i wrote a script, where it begins by checking if file exists or not.
If it exists, it truncates the database... (2 Replies)
Hi guys ,
i got segment fault , and when i trace , found it happens since the value of pointer which is returned by Struct S_client (*ptr) is zero
if (ptr !=0)i know , adding above line of code is not the solution and not correct for the case since above line only check for the pointer... (1 Reply)
Program to reverse a linked list by traversing only once. (1 Reply)
Discussion started by: VSSajjan
1 Replies
LEARN ABOUT CENTOS
strcat
STRCAT(3) Linux Programmer's Manual STRCAT(3)NAME
strcat, strncat - concatenate two strings
SYNOPSIS
#include <string.h>
char *strcat(char *dest, const char *src);
char *strncat(char *dest, const char *src, size_t n);
DESCRIPTION
The strcat() function appends the src string to the dest string, overwriting the terminating null byte (' ') at the end of dest, and then
adds a terminating null byte. The strings may not overlap, and the dest string must have enough space for the result. If dest is not
large enough, program behavior is unpredictable; buffer overruns are a favorite avenue for attacking secure programs.
The strncat() function is similar, except that
* it will use at most n bytes from src; and
* src does not need to be null-terminated if it contains n or more bytes.
As with strcat(), the resulting string in dest is always null-terminated.
If src contains n or more bytes, strncat() writes n+1 bytes to dest (n from src plus the terminating null byte). Therefore, the size of
dest must be at least strlen(dest)+n+1.
A simple implementation of strncat() might be:
char*
strncat(char *dest, const char *src, size_t n)
{
size_t dest_len = strlen(dest);
size_t i;
for (i = 0 ; i < n && src[i] != ' ' ; i++)
dest[dest_len + i] = src[i];
dest[dest_len + i] = ' ';
return dest;
}
RETURN VALUE
The strcat() and strncat() functions return a pointer to the resulting string dest.
CONFORMING TO
SVr4, 4.3BSD, C89, C99.
NOTES
Some systems (the BSDs, Solaris, and others) provide the following function:
size_t strlcat(char *dest, const char *src, size_t size);
This function appends the null-terminated string src to the string dest, copying at most size-strlen(dest)-1 from src, and adds a null ter-
minator to the result, unless size is less than strlen(dest). This function fixes the buffer overrun problem of strcat(), but the caller
must still handle the possibility of data loss if size is too small. The function returns the length of the string strlcat() tried to cre-
ate; if the return value is greater than or equal to size, data loss occurred. If data loss matters, the caller must either check the
arguments before the call, or test the function return value. strlcat() is not present in glibc and is not standardized by POSIX, but is
available on Linux via the libbsd library.
SEE ALSO bcopy(3), memccpy(3), memcpy(3), strcpy(3), string(3), strncpy(3), wcscat(3), wcsncat(3)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2012-07-19 STRCAT(3)
04-04-2011
