Problem in struct pointer

[sujin]

I'm not able to get the correct output, but the program seems to be fine. When I enter "sujin" as name and "100" as id, it outputs me only the first four characters of the name(5th char is some junk) and id. What would be the problem?.

#include <stdio.h>
#include <malloc.h>
#include <string.h>

typedef struct Employee
{
char *name;
int id;
}Emp;

void main()
{
Emp *e;
e = (Emp*)malloc(sizeof(Emp));
printf(&quot;Enter ur name\n&quot;
scanf(&quot;%s&quot;,&e->name);
int len = strlen((char*)&e->name);
printf(&quot;%d\n&quot;,len);
printf(&quot;Enter ur id\n&quot;
scanf(&quot;%d&quot;,&e->id);
printf(&quot;Your name is <%s> and id is <%d>\n&quot;,&e->name,e->id);
}


output:

Enter ur name
sujin
String length is 5
Enter ur id
100

Your name is <suji(some junk character)> and id is <100>

Character 'n' is not being displayed properly.

SJ.

 

[Leibnitz]

you have not allocate any memory for &quot;name&quot; and also it's a good idea to free the memory that you have allocate dynamically.In the present case you should free the memory allocated to &quot;e&quot; in the end of the program.

here is your program:


#include <stdio.h>
#include <malloc.h>
#include <string.h>

typedef struct Employee
{
char *name;
int id;
}Emp;

void main()
{
Emp *e;
e = (Emp*)malloc(sizeof(Emp));
e->name = (char*)malloc( sizeof(char)*25 );
printf(&quot;Enter ur name\n&quot;
scanf(&quot;%s&quot;,e->name);
int len = strlen(e->name);
printf(&quot;%d\n&quot;,len);
printf(&quot;Enter ur id\n&quot;
scanf(&quot;%d&quot;,&e->id);
printf(&quot;Your name is <%s> and id is <%d>\n&quot;,e->name,e->id);
free(e);
}

now it should work !

 

[sujin]

thanks a lot Leibnitz. It works fine.

SJ.

 

[tdatgod]

Hi,
you could always change your structure to be....

typedef struct Employee
{
char name[25];
int id;
}Emp;


which is esentially the same thing, but it saved the additional malloc for the name space. in reality the point of making it it a pointer means you can allocate only what is needed to store the users input. therefore the second malloc should be down after you ask the user for input.


char temp[25];

printf(&quot;Enter ur name\n&quot;
scanf(&quot;%s&quot;,&temp);
int len = strlen(temp);
e->name = (char*)malloc( len+1 ); /* don't forget the \0 */
strcpy(e->name,temp);


----

 

[siva]

Don't we need to free the memory allocated for name?

Does
free(e)

free the memory allocated to name too?

 

[siva]

Don't we need to free the memory allocated for name?

Does
free(e)

free the memory allocated to name too?

 

[siva]

Don't we need to free the memory allocated for name?

Does
free(e)

free the memory allocated to name too?

 

[siva]

Don't we need to free the memory allocated for name?

Does
free(e)

free the memory allocated to name too?

 

[ami123]

We have to free the memory allocated to name seprately with a
free(e->e_name)

But we have to ensure we call this free before we call the free(e)
amit
crazy_indian@lycos.com

to bug is human to debug devine