Linux 開啟檔案並寫入一段字串,同時讀出對應檔案的資訊--fopen()/fwrite()/fread()
阿新 • • 發佈:2019-02-10
test.dat 的內容如下:/* Test.c :create a file : Write a string to the file */ #include <stdio.h> #include <string.h> #include <stdlib.h> #define MAX 128 int main(){ FILE *fp = NULL; //notice char *filePath = "data/test.dat"; char stringDes[] = "Hello world"; stringDes[strlen(stringDes)] = '\0'; char buf[MAX]; /* open a file : FILE *fopen(const char *path, const char *mode); */ #if 1 fp = fopen(filePath,"at+"); if(NULL == fp){ perror("fp"); return -1; } printf("file open success! \n"); #endif /* write data block to a file: size_t fwrite(const void* buffer, size_t size, size_t count, FILE* stream); */ int i; for(i = 0; i <= 2; i++){ fwrite(stringDes,strlen(stringDes), 1, fp); fwrite("\n",1, 1, fp); fflush(fp); } printf("file set start \n"); fseek(fp,0,SEEK_SET); //set start file fread(buf,strlen(stringDes),1,fp); buf[strlen(stringDes)] = '\0'; printf("buf = %s \n",buf); fclose(fp); }