//FILE *fopen(char *filename,char *type);
//int fclose(FILE *stream);
//int fcloseall(void);
//int fget(FILE *stream);
//int fput(int ch , FILE *stream); stream = stdout --> 打到屏幕
//putc()与fputc()等价，getc()与fgetc()等价
//putchar(c)相当于fputc(c,stdout);
//getchar()相当于fgetc(stdin);
//feof()函数来测试是否到了文件尾
//ferror()函数来测试是否出错
//gets()-->遇到换行符和文件结束标示，则结束
//char * fputs(char * str, len , FILE *stream);
//fprintf(FILE * stream,"格式",数据)向流指针指向的文件输出-->文件相当于屏幕
//fscanf()从文件中读到指定的数组
//getch()从控制台读取一个字符，并且不回显在屏幕上
//int fflush(FILE *stream);
//int flushall();
//设置文件缓冲区函数
//void setbuf(FILE *stream,char *buf);
//void setbuf(FILE *stream,char *buf,int type,unsigned size);
//type:
// ---> _IOFBF 文件全部缓冲区,即缓冲区装满后，才能堆文件读写
// ---> _IOLBF 文件行缓冲,即缓冲区接收到一个换行符时,才能对文件读写
// ---> _IONBF 文件不缓冲
//移动文件指针的函数：
// long ftell(FILE *stream); -->得到文件指针离开文件开头的偏移量,返回-1时表示出错
// int rewind(FILE *stream); -->用于文件指针移到文件开头,成功返回0,不成功非0
// fseek(FILE *stream,long offset,int origin); -->用于把文件指针以origin为起点移动offset个字节
// origin:
// SEEK_SET 0 文件开头
// SEEK_CUR 1 文件指针当前位置
// SEEK_END 2 文件尾
//int fread(void *ptr,int nitems,FILE *stream);
//int fwrite(void *ptr,int size,int nitems,FILE *stream);
//非标准文件的读写 <io.h>
//int open(char *filename , int access);
//access:
// O_RDONLY -->只读
// O_WRONLY -->只写
// O_RDWR -->读写
// O_BINARY -->打开一个二进制文件
// O_TEXT -->打开一个文字文件
// O_APPEND -->文件指针指向末尾
// O_CREAT -->文件不存在时创建文件,属性按基本模式属性
// O_TRUNC -->若文件存在，将其长度缩为0,属性不变
//
//int close(int handle);
//读写函数
//int read(int handle,void *buf,int count);
// -->从handle相连的文件中,读取count个字节放到buf所指的缓冲区中
// -->返回值:-1表示出错,返回0表示文件结束
//int write(int handle,void *buf,int count);
// -->把count个字节从buf指向的缓冲区写入与handle相连的文件中
// -->返回实际写入的字节数
//int lseek(int handle,long offset,int fromwhere);
//long tell(int handle);
#include <iostream> #include <string.h> using namespace std; #define MAXSIZE 1024 #define FILENAME "F:/config/config1.txt" int WriteConfig(const char *filename,char *key_buf,char *valude_buf) { int ret = 0; int len = 0; int flag = 0; char filebuf[MAXSIZE * 8]; char linebuf[MAXSIZE]; char *ptmp = NULL; FILE *fp; if (filename == NULL || key_buf == NULL || valude_buf == NULL) { ret = -1; printf("filename == NULL || key_buf == NULL || valude_buf == NULL:"); return ret; } fp = fopen(filename,"w+t"); //没有该问价则创建一个 if (fp == NULL) { ret = -2; printf("fopen(filename) error:"); return ret; } //判断文件的是否满了 fseek(fp,0L,SEEK_END); len = ftell(fp); if (len >= MAXSIZE) { ret = -3; printf("file will full error:len >= MAXSIZ:"); return ret; } rewind(fp); //回到文件头部 //将每行数据取出来，放到linefile-->找key while (!feof(fp)) { memset(linebuf,0,sizeof(linebuf)); fgets(linebuf,MAXSIZE,fp); //判断改行有没有key ptmp = strstr(linebuf, key_buf); if (ptmp == NULL) //如果没有-->把改行内容暂存在filebuf { strcat(filebuf,linebuf); continue; } else //如果存在-->重写linebuf,然后再缓存到filebuf { sprintf(linebuf,"%s=%s\n",key_buf,valude_buf); strcat(filebuf,linebuf); flag = 1; continue; } } if (flag == 0) //不存在key-->将key和valude写到文件末尾 { char tmp[MAXSIZE]; sprintf(tmp,"%s=%s\n",key_buf,valude_buf); ret = fputs(tmp,fp); if (ret == EOF) { ret = -5; printf("ret = fputs(tmp,fp):"); return ret; } } else //如果存在-->将filebuf写到文件中 { fseek(fp,SEEK_END,SEEK_SET); fputs(filebuf, fp); } fclose(fp); return ret; } void trimspace(char *srcstr, char *outstr) { //printf("%s\n",srcstr); int left = 0; int right = strlen(srcstr) - 2; //有 ‘\n’ while (isspace(srcstr[left])) { left++; } while (isspace(srcstr[right])) { right--; } memset(outstr,0,sizeof(outstr)); strncpy(outstr,srcstr+left,right-left+1); outstr[right - left+1] = '\0'; return; } void ToWriteConfig() //写配置文件 { int ret = 0; char key_buf[MAXSIZE]; char valude_buf[MAXSIZE]; printf("请输入key: "); scanf("%s",&key_buf); printf("\n请输入valude: "); scanf("%s", &valude_buf); ret = WriteConfig(FILENAME,key_buf,valude_buf); if (ret != 0) { printf("WriteConfig() is error:%d",ret); } return; } int ReadConfig(const char *filename , char *key_buf , char *valude_buf,int *valude_len) { int ret = 0; char linebuf[MAXSIZE]; char *ptmp = NULL; FILE *fp; if (filename == NULL || key_buf == NULL || valude_buf == NULL || valude_len == NULL) { ret = -1; printf("ilename == NULL || key_buf == NULL || valude_buf == NULL || valude_len == NULL"); return ret; } fp = fopen(filename , "r"); if (fp == NULL) { ret = -2; printf("fopen() error"); return ret; } while (!feof(fp)) { memset(linebuf,0,sizeof(linebuf)); fgets(linebuf,MAXSIZE,fp); //printf("%s\n", linebuf); //寻找等号 ptmp = strchr(linebuf,'='); if (ptmp == NULL) { continue; } //寻找key ptmp = strstr(linebuf,key_buf); if (ptmp == NULL) { continue; } ptmp = ptmp + strlen(key_buf); //寻找 = 号 ptmp = strchr(ptmp,'='); ptmp += 1; //去掉空格 trimspace(ptmp,valude_buf); *valude_len = strlen(valude_buf); } fclose(fp); return ret; } void ToReadConfig() //读配置文件 { int ret = 0; int valude_len = 0; char key_buf[MAXSIZE]; char valude_buf[MAXSIZE]; printf("请你输入key:"); scanf("%s",&key_buf); ret = ReadConfig(FILENAME,key_buf,valude_buf,&valude_len); if (ret != 0) { printf(" ReadConfig() error:%d\n",ret); } printf("%s ",valude_buf); printf("%d\n", valude_len); return; } void menu() { printf("==================================\n"); printf("=== 1.写文件 ===\n"); printf("=== 2.读文件 ===\n"); printf("=== 0.退出 ===\n"); printf("==================================\n"); } int main() { int choice; while (1) { menu(); scanf("%d",&choice); switch (choice) { case 1: //写配置文件 ToWriteConfig(); break; case 2: //读配置文件 ToReadConfig(); break; case 0: exit(0); default: break; } } return 0; }
