Stack

stc.c

#include<stdio.h>
#include<stdlib.h>

struct stack      
{
	int info;
	struct stack *next;
};
typedef struct stack *s;

void push(s *sptr ,int p)
{
	
	s s2;
	s2=(s)malloc(sizeof(struct stack));
	if(s2==NULL)
	{
		printf("no memory");
		exit(1);
	}

	else
	{
		s2->info=p;
		s2->next=*sptr;
		*sptr=s2;
	}
}

int pop(s *sptr)
{
	s s2=*sptr; //Why???
	int px;
	if(*sptr == NULL)
	{
		printf("stack is empty");
		return;
	}
	else
	{
		px = (*sptr) -> info;
        *sptr = (*sptr) -> next;
        //free(sptr);
        return px;
	}
}

void disp(s *sptr)
{
    s temp=*sptr;	
	printf("the elements in stack are:\n");
    while(temp->next!=NULL)
	{
	    printf("%d\n",(temp)->info);
	    (temp)=(temp)->next;
	}
	printf("%d\n",temp -> info);
	
}


void main()
{
	int c,i;
    s s1=NULL;
   
   do{
	   printf("enter operation:-");
	   scanf("%d",&c);
	   switch(c)
	   {
	   case 1:  printf("enter data:-");
	             scanf("%d",&i);
	             push(&s1,i);
				 break;
			   
	   case 2:pop(&s1);break;
       case 3:disp(&s1);  break;
	   }
   }while(s1!=NULL);
}

[douglas@dell-studio Foo_codes]$ gcc stach_s.c -o stac
[douglas@dell-studio Foo_codes]$ ./stac
enter operation:-1
enter data:-23
enter operation:-1
enter data:-23
enter operation:-1
enter data:-345
enter operation:-3
the elements in stack are:
345
23
enter operation:-2
*** glibc detected *** ./stac: munmap_chunk(): invalid pointer: 0x00007fff603ed9f0 ***
======= Backtrace: =========
/lib/libc.so.6(+0x78a56)[0x7ffc392cfa56]
./stac[0x400734]
./stac[0x400816]
/lib/libc.so.6(__libc_start_main+0xf5)[0x7ffc39278455]
./stac[0x400589]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:06 1977217 /home/douglas/workspace/Foo_codes/stac
00600000-00601000 rw-p 00000000 08:06 1977217 /home/douglas/workspace/Foo_codes/stac
021a7000-021c8000 rw-p 00000000 00:00 0 [heap]
7ffc39042000-7ffc39057000 r-xp 00000000 08:06 142818 /usr/lib/libgcc_s.so.1
7ffc39057000-7ffc39256000 ---p 00015000 08:06 142818 /usr/lib/libgcc_s.so.1
7ffc39256000-7ffc39257000 rw-p 00014000 08:06 142818 /usr/lib/libgcc_s.so.1
7ffc39257000-7ffc393ee000 r-xp 00000000 08:06 1573015 /lib/libc-2.15.so
7ffc393ee000-7ffc395ee000 ---p 00197000 08:06 1573015 /lib/libc-2.15.so
7ffc395ee000-7ffc395f2000 r--p 00197000 08:06 1573015 /lib/libc-2.15.so
7ffc395f2000-7ffc395f4000 rw-p 0019b000 08:06 1573015 /lib/libc-2.15.so
7ffc395f4000-7ffc395f8000 rw-p 00000000 00:00 0
7ffc395f8000-7ffc39619000 r-xp 00000000 08:06 1573124 /lib/ld-2.15.so
7ffc397e7000-7ffc397ea000 rw-p 00000000 00:00 0
7ffc39815000-7ffc39819000 rw-p 00000000 00:00 0
7ffc39819000-7ffc3981a000 r--p 00021000 08:06 1573124 /lib/ld-2.15.so
7ffc3981a000-7ffc3981b000 rw-p 00022000 08:06 1573124 /lib/ld-2.15.so
7ffc3981b000-7ffc3981c000 rw-p 00000000 00:00 0
7fff603cf000-7fff603f0000 rw-p 00000000 00:00 0 [stack]
7fff603ff000-7fff60400000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
Aborted

Fixed and working