A easy way to contruct a linklist and some base options. written by C

Linklist.c

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

#define NLEN 5
#define NVAL 5

typedef struct Nameval Nameval;
typedef void(*func)(Nameval *, void *);
struct Nameval 
{
	char *name;
	int  value;
	Nameval *next;
};

Nameval *newitem(char *name, int value)
{
	Nameval *newp;

	newp = (Nameval *)malloc(sizeof(Nameval));
	if(newp == NULL)
		exit(1);
	newp->name = name;
	newp->value = value;
	newp->next = NULL;
	return newp;

}

Nameval *addend(Nameval *listp, Nameval *items)
{
	Nameval *p;

	if(listp == NULL)
		return items;
	for(p = listp; p->next != NULL; p = p->next)
		;
	p->next = items;
	return listp;
}

//print list items
void printnv(Nameval *listp, void *arg)
{
	char *fmt;

	fmt =(char *)arg;
	printf(fmt,listp->name,listp->value);
}

void apply(Nameval *listp,func fp,void *arg)
{
	for(;listp!= NULL; listp = listp->next)
		fp(listp,arg);
	printf("\n");
}

//loop to revese a list
Nameval *revese(Nameval *listp)
{
	Nameval *current, *p;

	if(listp == NULL)
		return NULL;
	current = listp->next; //point to first item
	while(current->next != NULL)
	{
		p = current ->next;  //point to second item
		current->next = p->next; //make first item point to thrid
		p->next = listp->next; //make second item point to oldfirst
		listp->next = p; //reset the new first item
	} 

	return listp;
}

Nameval *delitem(Nameval *listp, char *name)
{
	Nameval *prev, *p;

	prev = NULL;
	for(p = listp->next; p != NULL;p = p->next)
	{ 
		if(strcmp(name, p->name) == 0)
		{ 
			if(prev == NULL)
				listp->next = p->next;
			else
				prev->next = p->next;
			free(p);
			return listp;
		}
		prev = p; //save the previous item.
	}

	printf("delitem:%s can't find\n",name);
	return NULL;
}

Nameval *insertitem(Nameval *listp, char *name,Nameval *newp)
{
	Nameval *p;

	for(p = listp->next; p != NULL; p= p->next)
	{
		if(strcmp(name, p->name) == 0)
		{
			newp->next = p->next;
			p->next = newp;
			return listp;
		}
	}

	printf("insertitem:%s can't find\n",name);
	return NULL;
}

int main(int argc, const char *argv[])
{
	Nameval *item,*nlist;
	//init the head pointer
	nlist = (Nameval *)malloc(sizeof(Nameval));
	//if(nlist == NULL)
	//	exit(0);
	//nlist->next = NULL;	

	char *name[NLEN] = {"jesse","sky","ward","may","simmons"};
	int  num[NVAL]={2,3,1,5,4};
	int  i;

	//loop to create a list
	for(i = 0; i < 5; i++)
	{
		nlist = addend(nlist,newitem(name[i],num[i]));
	}

	apply(nlist,printnv,"%s:%d  ");
	nlist = revese(nlist);
	apply(nlist,printnv,"%s:%d  ");
	nlist = delitem(nlist,"may");
	apply(nlist,printnv,"%s:%d  ");
	nlist = insertitem(nlist,"sky",newitem("fize",6));
	apply(nlist,printnv,"%s:%d  ");
	return 0;
}