C语言实现电子英汉词典：基于文件存储的增删改查系统

#include <stdio.h>	//引入库函数
#include <stdlib.h>
#include <string.h>
#define szWORD 50	//单词长度最大50
#define szSTRN 200	//释义长度最大200
#define szProject sizeof(struct Dictionary)
char fileDict[szSTRN];
typedef struct 	Dictionary{
char word[szWORD];
char mean[szSTRN];
} Project ; //定义字典结构体，定义两个字符型变量单词和释义
fpos_t consult(char *word, char *mean)
{
FILE * f = 0; Project 	i; 
int r = 0; fpos_t p = 0;
if(!word) return 0;
f = fopen(fileDict, "rb");
if (!f) return 0;
while(!feof(f)) {
	fgetpos(f, &p);
	r = fread(&i, szProject , 1, f);
	if(r < 1) break;
	if(i.word[0] == 0) continue;
	if(strcmp(i.word , word)) continue;
	if(mean) strcpy(mean, i.mean );
	fclose(f);
	return p+1; }
fclose(f);
return 0;}
void Search(void);
void Append(void);
void Delete(void);
void Update(void);
 
int main(int argk, char * argh[])
{
int m= 0;
if(argk>1) 
	strcpy(fileDict, argh[1]);
else
	strcpy(fileDict, "c:\\dict.txt");
for(;;) {
printf("\n\
--------------------\n\
欢迎使用电子英汉词典！\n\
--------------------\n\
1 - 查询词条\n\
2 - 新增词条\n\
3 - 删除词条\n\
4 - 修改词条\n\
5 - 退出词典\n\
--------------------\n");
	m = getchar() - '0';
	switch(m) {
case 1: Search();break;
case 2: Append();break;
case 3: Delete();break;
case 4: Update();break;
default : return 0;}
}
return 0;
}
 
void Search(void)
{
	Project i; fpos_t p = 0;
memset(&i, 0, szProject );
printf("please input the word 	you want："); scanf("%s", i.word );
p = consult(i.word, i.mean );
if(p==0) {
	printf("sorry do not find what you want！\n");
	return;
}
printf("单词：%s\n释义：%s", i.word , i.mean );
}
void Append(void)
{
Project 	i; FILE * f = 0; fpos_t p = 0;
memset(&i, 0, szProject );
printf("please input the word you want："); scanf("%s", i.word );
p = consult(i.word,0);
if(p) 	 {
	printf("sorry do not find what you want!\n");
	return;
}
printf("please giving the meaning，按确认结束："); 
fflush(stdin);
gets(i.mean );
f = fopen(fileDict, "ab");
fwrite(&i, szProject , 1, f);
fclose(f);
printf("词条已新增\n");
}
void Delete(void)
{
	Project 	i; FILE * f = 0; fpos_t p = 0;
memset(&i, 0, szProject );
printf("please input the word you want："); scanf("%s", i.word );
p = consult(i.word, 0 );
if(p==0) {
	printf("sorry do not find what you want！\n");
	return;
}
p--;
memset(&i, 0, szProject);
f = fopen(fileDict, "rb+");
fsetpos(f, &p);
fwrite(&i, szProject , 1, f);
fclose(f);
printf("词条已删除\n");
}
void Update(void)
{
	Project 	i; FILE * f = 0; fpos_t p = 0; 
memset(&i, 0, szProject );
printf("please input the word you want："); scanf("%s", i.word );
p = consult(i.word, 0 );
if(p==0) {
	printf("sorry do not find what you want！\n");
	return;
}
p--;
printf("please giving the meaning，按确认结束（输入drop放弃修改）："); 
fflush(stdin);
gets(i.mean );
if(strstr(i.mean ,"drop")) {
	printf("已放弃修改！\n");
	return ;
}
f = fopen(fileDict, "rb+");
fsetpos(f, &p);
fwrite(&i, szProject , 1, f);
fclose(f);
printf("词条已保存\n");
}