linked list problem

B

bofh1234

Hello,

I am having a problem with linked lists. My program is based on a
client server model. The client sends some packets of data to the
server. The server reads those packets and is supposed to store the
data in a linked list. It looks like everything works except for the
fact that the linked list only stores the last value sent and the
number of nodes in the linked list is way to high. For example the
client sends 4 create requests to the server, there should be 4 nodes
in the server but there turns out to be 12. All 12 contain the values
of the last request. I am sure the problem is with the linked list
code. If I put in an array it works, but I need a varible size so I
have to use a linked list. Here is my server code.

When create is called the correct varname and varval are printed.
However when findvar is called things go wrong. I am including the
output from a run of the server. From the output there appear to be
two problems, 1) the table does not get created correctly 2) the
findvar function is going crazy most likely due to the table not being
created correctly. What am I doing wrong with the linked lists?

The client code is 4 creates followed by reading those 4 values from
the table.

Thanks,
Mike

/* server code */
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <messages.h>

#define QLEN 5 /* maximum connection queue length */

#define or ||
#define and &&

struct Table1 {
int vartype;
char *varname;
char *ptr;
struct Table1 *next;
};
struct Table1 *Table1ptr=NULL, *temp;

extern int errno;

int serverA(int);
void create(int, struct Table1 **);
void findvar(int, struct Table1 *);
void updatevar(int);
void deletevar(int);
void reaper(int);

int errexit(const char *format, ...);

int passiveTCP(const char *service, int qlen);

int i=0;

/*-------------------------------------------------------------------
* main
*-----------------------------------------------------------------*/
int main(int argc, char *argv[])
{
char *service = "3445"; /* service name or port number */
struct sockaddr_in fsin; /* the address of a client */
int alen; /* length of client's address */
int msock; /* master server socket */
int ssock; /* slave server socket */

switch (argc) {
case 1:
break;
case 2:
service = argv[1];
break;
default:
errexit("usage: serverA [port]\n");
}

msock = passiveTCP(service, QLEN);

(void) signal(SIGCHLD, reaper);
alen = sizeof(fsin);
ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
exit(dsmd(ssock));
}

/*-------------------------------------------------------------------
* serverA
*-----------------------------------------------------------------*/
int serverA(int fd)
{
int size, n, msgtype=0;
char *bufptr;

for ( ; ; ) {
bufptr=(char*)(&msgtype);
size=sizeof(int);

while ((n=read(fd, bufptr, size)) >0) {
size-=n;
bufptr+=n;
}
if (msgtype == 0)
break;

switch(msgtype) {
case 1:
create(fd, &Table1ptr);
break;
case 2:
findvar(fd, Table1ptr);
break;
case 3:
updatevar(fd);
break;
case 4:
deletevar(fd);
break;
default:
errexit("The server is shutting down due to a problem\n");
}
msgtype=0;
}
return 0;
}

/*-------------------------------------------------------------------
* create procedure for creating variables
*------------------------------------------------------------------*/
void create(int fd, struct Table1 **q)
{
int n, size;
char *createpack;
struct Table1 *temp;

createpacket.requesttype=1;
createpack=(char*)(&createpacket)+4;
size=sizeof(createpacket)-sizeof(int);

while ((n = read(fd, (void*)createpack, size)) >0 ){
size-=n;
createpack+=n;
}

temp = *q;
if(*q==NULL) {
*q=malloc(sizeof(struct Table1));
temp = *q;
}
else {
while((temp->next)!=NULL) {
temp=temp->next;
}
temp->next = malloc(sizeof(struct Table1));
temp=temp->next;
}

temp->varname=createpacket.varname;
temp->vartype=createpacket.vartype;
temp->ptr=createpacket.varval;
temp->next = NULL;

rpacket.rescode=0;
strcpy(rpacket.rvarval,createpacket.varval);
strcpy(rpacket.rdescrip,"");
printf("createvar temp-vartype created = %s \n", temp->varname);
printf("createvar pt->ptr = %s \n", temp->ptr);

write(fd, &rpacket, sizeof(rpacket));
}

/*-------------------------------------------------------------------
* findvar
*------------------------------------------------------------------*/
void findvar(int fd, struct Table1 *pt)
{
int n, size;
char *findpack;

findpacket.requesttype=2;
findpack=(char*)(&findpacket)+4;
size=sizeof(findpacket)-sizeof(int);

while ((n = read(fd, (void*)findpack, size)) >0){
size-=n;
findpack+=n;
}

while (pt!=NULL) {
printf("findpacke varname = %s \n", findpacket.varname);
printf("findvar pt->varname = %s \n", pt->varname);
printf("findvar pt->ptr = %s \n", pt->ptr);
printf("size = %d \n", i); i++;

if (strcmp(findpacket.varname,pt->varname) == 0) {
rpacket.rescode=0;
strcpy(rpacket.rvarval,pt->ptr);
break;
}
else {
rpacket.rescode=-1;
strcpy(rpacket.rdescrip,"varible not found");
}
pt=pt->next;
}
write(fd, &rpacket, sizeof(rpacket));
}


/* output from server */
createvar temp-vartype created = a
createvar pt->ptr = 140
createvar temp-vartype created = b
creatvar pt->ptr = 240
createvar temp-vartype created = c
createvar pt->ptr = 340
createvar temp-vartype created = d
createvar pt->ptr = 440
findpacke varname = a
findvar pt->varname = d
findvar pt->ptr = 440
size = 0
findpacke varname = a
findvar pt->varname = d
findvar pt->ptr = 440
size = 1
findpacke varname = a
findvar pt->varname = d
findvar pt->ptr = 440
size = 2
findpacke varname = a
findvar pt->varname = d
findvar pt->ptr = 440
size = 3
findpacke varname = b
findvar pt->varname = d
findvar pt->ptr = 440
size = 4
findpacke varname = b
findvar pt->varname = d
findvar pt->ptr = 440
size = 5
findpacke varname = b
findvar pt->varname = d
findvar pt->ptr = 440
size = 6
findpacke varname = b
findvar pt->varname = d
findvar pt->ptr = 440
size = 7
findpacke varname = c
findvar pt->varname = d
findvar pt->ptr = 440
size = 8
findpacke varname = c
findvar pt->varname = d
findvar pt->ptr = 440
size = 9
findpacke varname = c
findvar pt->varname = d
findvar pt->ptr = 440
size = 10
findpacke varname = c
findvar pt->varname = d
findvar pt->ptr = 440
size = 11
findpacke varname = d
findvar pt->varname = d
findvar pt->ptr = 440
size = 12


/* this should be the output from the server */
createvar temp-vartype created = a
createvar pt->ptr = 140
createvar temp-vartype created = b
creatvar pt->ptr = 240
createvar temp-vartype created = c
createvar pt->ptr = 340
createvar temp-vartype created = d
createvar pt->ptr = 440
findpacke varname = a
findvar pt->varname = a
findvar pt->ptr = 140
size = 0
findpacke varname = b
findvar pt->varname = a
findvar pt->ptr = 140
size = 1
findpacke varname = b
findvar pt->varname = b
findvar pt->ptr = 240
size = 2
findpacke varname = c
findvar pt->varname = a
findvar pt->ptr = 140
size = 3
findpacke varname = c
findvar pt->varname = b
findvar pt->ptr = 240
size = 4
findpacke varname = c
findvar pt->varname = c
findvar pt->ptr = 340
size = 5
findpacke varname = d
findvar pt->varname = a
findvar pt->ptr = 140
size = 6
findpacke varname = d
findvar pt->varname = b
findvar pt->ptr = 240
size = 7
findpacke varname = d
findvar pt->varname = c
findvar pt->ptr = 340
size = 8
findpacke varname = d
findvar pt->varname = d
findvar pt->ptr = 440
size = 9
 
R

rageratwork

Hello,

I am having a problem with linked lists. My program is based on a
client server model. The client sends some packets of data to the
server. The server reads those packets and is supposed to store the
data in a linked list. It looks like everything works except for the
fact that the linked list only stores the last value sent and the
number of nodes in the linked list is way to high. For example the
client sends 4 create requests to the server, there should be 4 nodes
in the server but there turns out to be 12. All 12 contain the values
of the last request. I am sure the problem is with the linked list
code. If I put in an array it works, but I need a varible size so I
have to use a linked list. Here is my server code.

When create is called the correct varname and varval are printed.
However when findvar is called things go wrong. I am including the
output from a run of the server. From the output there appear to be
two problems, 1) the table does not get created correctly 2) the
findvar function is going crazy most likely due to the table not being
created correctly. What am I doing wrong with the linked lists?

The client code is 4 creates followed by reading those 4 values from
the table.

Thanks,
Mike

/* server code */
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <messages.h>

#define QLEN 5 /* maximum connection queue length */

#define or ||
#define and &&

struct Table1 {
int vartype;
char *varname;
char *ptr;
struct Table1 *next;
};
struct Table1 *Table1ptr=NULL, *temp;

extern int errno;

int serverA(int);
void create(int, struct Table1 **);
void findvar(int, struct Table1 *);
void updatevar(int);
void deletevar(int);
void reaper(int);

int errexit(const char *format, ...);

int passiveTCP(const char *service, int qlen);

int i=0;

/*-------------------------------------------------------------------
* main
*-----------------------------------------------------------------*/
int main(int argc, char *argv[])
{
char *service = "3445"; /* service name or port number */
struct sockaddr_in fsin; /* the address of a client */
int alen; /* length of client's address */
int msock; /* master server socket */
int ssock; /* slave server socket */

switch (argc) {
case 1:
break;
case 2:
service = argv[1];
break;
default:
errexit("usage: serverA [port]\n");
}

msock = passiveTCP(service, QLEN);

(void) signal(SIGCHLD, reaper);
alen = sizeof(fsin);
ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
exit(dsmd(ssock));
}

/*-------------------------------------------------------------------
* serverA
*-----------------------------------------------------------------*/
int serverA(int fd)
{
int size, n, msgtype=0;
char *bufptr;

for ( ; ; ) {
bufptr=(char*)(&msgtype);
size=sizeof(int);

while ((n=read(fd, bufptr, size)) >0) {
size-=n;
bufptr+=n;
}
if (msgtype == 0)
break;

switch(msgtype) {
case 1:
create(fd, &Table1ptr);
break;
case 2:
findvar(fd, Table1ptr);
break;
case 3:
updatevar(fd);
break;
case 4:
deletevar(fd);
break;
default:
errexit("The server is shutting down due to a problem\n");
}
msgtype=0;
}
return 0;
}

/*-------------------------------------------------------------------
* create procedure for creating variables
*------------------------------------------------------------------*/
void create(int fd, struct Table1 **q)
{
int n, size;
char *createpack;
struct Table1 *temp;

createpacket.requesttype=1;
createpack=(char*)(&createpacket)+4;
size=sizeof(createpacket)-sizeof(int);

while ((n = read(fd, (void*)createpack, size)) >0 ){
size-=n;
createpack+=n;
}

temp = *q;
if(*q==NULL) {
*q=malloc(sizeof(struct Table1));
temp = *q;
}
else {
while((temp->next)!=NULL) {
temp=temp->next;
}
temp->next = malloc(sizeof(struct Table1));
temp=temp->next;
}

temp->varname=createpacket.varname;
temp->vartype=createpacket.vartype;
temp->ptr=createpacket.varval;
temp->next = NULL;

rpacket.rescode=0;
strcpy(rpacket.rvarval,createpacket.varval);
strcpy(rpacket.rdescrip,"");
printf("createvar temp-vartype created = %s \n", temp->varname);
printf("createvar pt->ptr = %s \n", temp->ptr);

write(fd, &rpacket, sizeof(rpacket));
}

/*-------------------------------------------------------------------
* findvar
*------------------------------------------------------------------*/
void findvar(int fd, struct Table1 *pt)
{
int n, size;
char *findpack;

findpacket.requesttype=2;
findpack=(char*)(&findpacket)+4;
size=sizeof(findpacket)-sizeof(int);

while ((n = read(fd, (void*)findpack, size)) >0){
size-=n;
findpack+=n;
}

while (pt!=NULL) {
printf("findpacke varname = %s \n", findpacket.varname);
printf("findvar pt->varname = %s \n", pt->varname);
printf("findvar pt->ptr = %s \n", pt->ptr);
printf("size = %d \n", i); i++;

if (strcmp(findpacket.varname,pt->varname) == 0) {
rpacket.rescode=0;
strcpy(rpacket.rvarval,pt->ptr);
break;
}
else {
rpacket.rescode=-1;
strcpy(rpacket.rdescrip,"varible not found");
}
pt=pt->next;
}
write(fd, &rpacket, sizeof(rpacket));
}
Click to expand...

[snip output]

In create() even though you allocate memory for each Table1, you never
allocate space for the varname and ptr fields. You just set them to
values in createpacket, wherever that comes from. Unless you allocate
new storage for those fields in createpacket somewhere else not listed
here, it looks to me like all the Table1 entries would point to the
same storage which would contain the last values set in them.

Also it looks like some of your pointer arithmatic may be off and you
aren't checking to make sure malloc doesn't fail.

Dave.
 
R

rageratwork

Hello,

I am having a problem with linked lists. My program is based on a
client server model. The client sends some packets of data to the
server. The server reads those packets and is supposed to store the
data in a linked list. It looks like everything works except for the
fact that the linked list only stores the last value sent and the
number of nodes in the linked list is way to high. For example the
client sends 4 create requests to the server, there should be 4 nodes
in the server but there turns out to be 12. All 12 contain the values
of the last request. I am sure the problem is with the linked list
code. If I put in an array it works, but I need a varible size so I
have to use a linked list. Here is my server code.

When create is called the correct varname and varval are printed.
However when findvar is called things go wrong. I am including the
output from a run of the server. From the output there appear to be
two problems, 1) the table does not get created correctly 2) the
findvar function is going crazy most likely due to the table not being
created correctly. What am I doing wrong with the linked lists?

The client code is 4 creates followed by reading those 4 values from
the table.

Thanks,
Mike

/* server code */
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <messages.h>

#define QLEN 5 /* maximum connection queue length */

#define or ||
#define and &&

struct Table1 {
int vartype;
char *varname;
char *ptr;
struct Table1 *next;
};
struct Table1 *Table1ptr=NULL, *temp;

extern int errno;

int serverA(int);
void create(int, struct Table1 **);
void findvar(int, struct Table1 *);
void updatevar(int);
void deletevar(int);
void reaper(int);

int errexit(const char *format, ...);

int passiveTCP(const char *service, int qlen);

int i=0;

/*-------------------------------------------------------------------
* main
*-----------------------------------------------------------------*/
int main(int argc, char *argv[])
{
char *service = "3445"; /* service name or port number */
struct sockaddr_in fsin; /* the address of a client */
int alen; /* length of client's address */
int msock; /* master server socket */
int ssock; /* slave server socket */

switch (argc) {
case 1:
break;
case 2:
service = argv[1];
break;
default:
errexit("usage: serverA [port]\n");
}

msock = passiveTCP(service, QLEN);

(void) signal(SIGCHLD, reaper);
alen = sizeof(fsin);
ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
exit(dsmd(ssock));
}

/*-------------------------------------------------------------------
* serverA
*-----------------------------------------------------------------*/
int serverA(int fd)
{
int size, n, msgtype=0;
char *bufptr;

for ( ; ; ) {
bufptr=(char*)(&msgtype);
size=sizeof(int);

while ((n=read(fd, bufptr, size)) >0) {
size-=n;
bufptr+=n;
}
if (msgtype == 0)
break;

switch(msgtype) {
case 1:
create(fd, &Table1ptr);
break;
case 2:
findvar(fd, Table1ptr);
break;
case 3:
updatevar(fd);
break;
case 4:
deletevar(fd);
break;
default:
errexit("The server is shutting down due to a problem\n");
}
msgtype=0;
}
return 0;
}

/*-------------------------------------------------------------------
* create procedure for creating variables
*------------------------------------------------------------------*/
void create(int fd, struct Table1 **q)
{
int n, size;
char *createpack;
struct Table1 *temp;

createpacket.requesttype=1;
createpack=(char*)(&createpacket)+4;
size=sizeof(createpacket)-sizeof(int);

while ((n = read(fd, (void*)createpack, size)) >0 ){
size-=n;
createpack+=n;
}

temp = *q;
if(*q==NULL) {
*q=malloc(sizeof(struct Table1));
temp = *q;
}
else {
while((temp->next)!=NULL) {
temp=temp->next;
}
temp->next = malloc(sizeof(struct Table1));
temp=temp->next;
}

temp->varname=createpacket.varname;
temp->vartype=createpacket.vartype;
temp->ptr=createpacket.varval;
temp->next = NULL;

rpacket.rescode=0;
strcpy(rpacket.rvarval,createpacket.varval);
strcpy(rpacket.rdescrip,"");
printf("createvar temp-vartype created = %s \n", temp->varname);
printf("createvar pt->ptr = %s \n", temp->ptr);

write(fd, &rpacket, sizeof(rpacket));
}

/*-------------------------------------------------------------------
* findvar
*------------------------------------------------------------------*/
void findvar(int fd, struct Table1 *pt)
{
int n, size;
char *findpack;

findpacket.requesttype=2;
findpack=(char*)(&findpacket)+4;
size=sizeof(findpacket)-sizeof(int);

while ((n = read(fd, (void*)findpack, size)) >0){
size-=n;
findpack+=n;
}

while (pt!=NULL) {
printf("findpacke varname = %s \n", findpacket.varname);
printf("findvar pt->varname = %s \n", pt->varname);
printf("findvar pt->ptr = %s \n", pt->ptr);
printf("size = %d \n", i); i++;

if (strcmp(findpacket.varname,pt->varname) == 0) {
rpacket.rescode=0;
strcpy(rpacket.rvarval,pt->ptr);
break;
}
else {
rpacket.rescode=-1;
strcpy(rpacket.rdescrip,"varible not found");
}
pt=pt->next;
}
write(fd, &rpacket, sizeof(rpacket));
}
Click to expand...

[snip output]

In create() even though you allocate memory for each Table1, you never
allocate space for the varname and ptr fields. You just set them to
values in createpacket, wherever that comes from. Unless you allocate
new storage for those fields in createpacket somewhere else not listed
here, it looks to me like all the Table1 entries would point to the
same storage which would contain the last values set in them.

Also it looks like some of your pointer arithmatic may be off and you
aren't checking to make sure malloc doesn't fail.

Dave.
 
B

bofh1234

Yeah I have to check if malloc returned NULL. I took it out to see if
that was causing the problem. So I allocated memory for the struct
Table1. I thought that when I did the malloc(sizeof (struct Table1))
it allocated the memory for the struct and setup the memory inside the
struct so I could start assigning things to it. I guess I was wrong.
So what you are telling I have to do something like this (not real
code)

char *ptrtostructvarname;
char *ptrtostructptr;
int *ptrtostructvartype;

*q = malloc(sizeof struct Table1)
check if q is null
*ptrtostructvarname=malloc(sizeof(createpacket.varname));
*ptrtostructptr=malloc(sizeof(createpacket.varval));
*ptrtostructvartype=malloc(sizeof(createpacket.vartype));

Then how do I associate these new pointers to the Table?

Thanks,
Mike
 
T

TJW

Yeah I have to check if malloc returned NULL. I took it out to see if
that was causing the problem.
Click to expand...
This is good practice, but is not your problem in this case.
So I allocated memory for the struct
Table1. I thought that when I did the malloc(sizeof (struct Table1))
it allocated the memory for the struct and setup the memory inside the
struct so I could start assigning things to it. I guess I was wrong.
Click to expand...
malloc allocates enough memory to store your structure. The
elements of your structure are:
struct Table1 {
int vartype;
char *varname;
char *ptr;
struct Table1 *next;
};
Click to expand...
so you've allocated enough memory to store an int and 3
pointers. The next step is to point the pointers to something
meaningful. You've already done it once with the statement:
temp->next = malloc(sizeof(struct Table1));
Click to expand...
Now temp->next points to a place in memory allocated to store a
structure. varname and ptr still have no meaning. You need the
assignment
temp->varname = malloc(sizeof(char));
or better yet:
tmp->varname = malloc(sizeof(*(tmp->varname)));
and the equivalent for ptr. You should also check these values to
assure that malloc succeeded in allocating the memory.

Good Luck,
-TJW
 
C

CBFalconer

I am having a problem with linked lists. My program is based on a
client server model. The client sends some packets of data to the
server. The server reads those packets and is supposed to store the
data in a linked list. It looks like everything works except for the
fact that the linked list only stores the last value sent and the
number of nodes in the linked list is way to high. For example the
client sends 4 create requests to the server, there should be 4 nodes
in the server but there turns out to be 12. All 12 contain the values
of the last request. I am sure the problem is with the linked list
code. If I put in an array it works, but I need a varible size so I
have to use a linked list. Here is my server code.

When create is called the correct varname and varval are printed.
However when findvar is called things go wrong. I am including the
output from a run of the server. From the output there appear to be
two problems, 1) the table does not get created correctly 2) the
findvar function is going crazy most likely due to the table not being
created correctly. What am I doing wrong with the linked lists?

The client code is 4 creates followed by reading those 4 values from
the table.

/* server code */
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <messages.h>
Click to expand...

None of those include files, apart from stdlib.h, stdio.h, string.h
have anything to do with the standard C language. Reduce your
problem to something expressible (and compilable) in standard C, in
about 100 lines or less, and then ask again. Otherwise take it all
to some newsgroup that deals with your particular system. This is
not it.

--
"If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson
More details at: <http://cfaj.freeshell.org/google/>
Also see <http://www.safalra.com/special/googlegroupsreply/>
 
R

rageratwork

Yeah I have to check if malloc returned NULL. I took it out to see if
that was causing the problem. So I allocated memory for the struct
Table1. I thought that when I did the malloc(sizeof (struct Table1))
it allocated the memory for the struct and setup the memory inside the
struct so I could start assigning things to it. I guess I was wrong.
So what you are telling I have to do something like this (not real
code)

char *ptrtostructvarname;
char *ptrtostructptr;
int *ptrtostructvartype;

*q = malloc(sizeof struct Table1)
check if q is null
*ptrtostructvarname=malloc(sizeof(createpacket.varname));
*ptrtostructptr=malloc(sizeof(createpacket.varval));
*ptrtostructvartype=malloc(sizeof(createpacket.vartype));

Then how do I associate these new pointers to the Table?

Thanks,
Mike
Click to expand...

Sortof...

// conditional to find end of list and allocate temp
...
// temp is allocated and ready to be populated

temp->varname = malloc( number of bytes to hold the name );
temp->ptr = malloc( number of bytes to hold whatever ptr points at
);

strncpy (temp->varname, createpacket.varname, number of bytes
allocated );

// this should be ok as it is
temp->vartype=createpacket.vartype;

memcpy (temp->ptr, createpacket.varval, number of bytes allocated );

// this is also ok as is
temp->next = NULL;

// rest of create()
...

You have to remember now when free-ing each Table1 element in the list,
first free the memory allocated for varname and ptr.
 
J

Joe Smith

[non Standard stuff snipped]
None of those include files, apart from stdlib.h, stdio.h, string.h
have anything to do with the standard C language. Reduce your
problem to something expressible (and compilable) in standard C, in
about 100 lines or less, and then ask again. Otherwise take it all
to some newsgroup that deals with your particular system. This is
not it.
Click to expand...

Every time I've seen a post that endeavors to do something with the
client/server model, it goes OT but quickly. Is this inevitable? Joe
 
C

CBFalconer

Joe said:
[non Standard stuff snipped]
None of those include files, apart from stdlib.h, stdio.h, string.h
have anything to do with the standard C language. Reduce your
problem to something expressible (and compilable) in standard C, in
about 100 lines or less, and then ask again. Otherwise take it all
to some newsgroup that deals with your particular system. This is
not it.
Click to expand...

Every time I've seen a post that endeavors to do something with the
client/server model, it goes OT but quickly. Is this inevitable?
Click to expand...

There are neither clients nor servers mentioned in the C standard.
So yes, barring writing everything in standard C. I do not
consider this practical for such an application.

Of course you could define client and server in such a way as to
make it feasible.

--
"If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson
More details at: <http://cfaj.freeshell.org/google/>
Also see <http://www.safalra.com/special/googlegroupsreply/>
 
T

TJW

None of those include files, apart from stdlib.h, stdio.h, string.h
have anything to do with the standard C language. Reduce your
problem to something expressible (and compilable) in standard C, in
about 100 lines or less, and then ask again. Otherwise take it all
to some newsgroup that deals with your particular system. This is
not it.
Click to expand...

But in this particular case his question is essentially "I am
having problems putting data in a linked list. Here is my code
(that may or may not have something to do with clients and
servers):"

I agree that ideally the system specific stuff should have been
pruned and the code compilable, but his question at heart was a
relatively basic C question so I didn't mind answering it too
much. Is this the wrong attitude for this group?
 
V

Vladimir Oka

TJW opined:
But in this particular case his question is essentially "I am
having problems putting data in a linked list. Here is my code
(that may or may not have something to do with clients and
servers):"
Click to expand...

I think the problem in these cases really boils down to:

a) there was too much code, i.e. OP should pare down to minimal
compilable example that still exhibits the problem
b) existence of non-standard features makes it difficult to say with
confidence that the problem is *not* in those same features (about
which c.l.c crowd may not know much or anything at all), but in
the rest of the, possibly standard, code
I agree that ideally the system specific stuff should have been
pruned and the code compilable, but his question at heart was a
relatively basic C question so I didn't mind answering it too
much. Is this the wrong attitude for this group?
Click to expand...

No, but removing obstacles as above, should still be encouraged, if not
enforced.

--
"Open Standards, Open Documents, and Open Source"

-- Scott Bradner (Open Sources, 1999 O'Reilly and Associates)

<http://clc-wiki.net/wiki/Introduction_to_comp.lang.c>
 
J

Joe Smith

TJW said:
CBFalconer <[email protected]> writes:
Click to expand...
[non Standard stuff can hit the road]
But in this particular case his question is essentially "I am
having problems putting data in a linked list. Here is my code
(that may or may not have something to do with clients and
servers):"

I agree that ideally the system specific stuff should have been
pruned and the code compilable, but his question at heart was a
relatively basic C question so I didn't mind answering it too
much. Is this the wrong attitude for this group?
Click to expand...

[freshly snipped elsewhere]
This is always a temptation:

<NOTHING-TO-DO-WITH-STANDARD-C-HERE>

int opt = 1;

setsockopt(server_sd, SOL_SOCKET, SO_REUSEADDR, (char *)&opt,
sizeof(opt));

</NOTHING-TO-DO-WITH-STANDARD-C-HERE>

I don't know why this couldn't have been posted at alt.alt.test with an
appropriate link for the curious. My guess is that if you _struggle_ with
topicality, then you do not have the wrong attitude for this group. Joe
 

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