stream表示流

1：fputs

int fputs(int character,FILE* stream);

#include<stdio.h>int main()
{FILE* pf=fopen("data.txt", "w");//打开判断是否成功if (pf == NULL){perror("fopen");return 1;}fputc('a', pf);fputc('a', pf);fputc('a', pf);fputc('a', pf);fputc('a', pf);//关闭fclose(pf);pf == NULL;return 0;
}

fputc的第二个是字符，不是字符串。

2：fgetc

int getc(FILE* stream);

使用int类型来接收返回值，是因为如果返回错误就算返回-1（EOF）

int main()
{FILE* pf = fopen("data.txt", "r");//打开判断是否成功if (pf == NULL){perror("fopen");return 1;}int ch = fgetc(pf);printf("%c\n",ch);//关闭fclose(pf);pf == NULL;return 0;
}

ch表示一次接受一个字符

3：fputs

    int fputs(const char* str, FILE * stream);

int main()
{FILE* pf = fopen("data.txt", "w");if (pf == NULL){perror("fopen");return 1;}fputs("i ilke c", pf);fclose(pf);pf = NULL;return 0;
}

4：fgets

char* fgets(char* str, int num, FILE * stream);

int main()
{char str[100];fgets(str,100,stdin);printf("%s", str);return 0;
}

5：fprintf

    int fprintf(FILE * stream, const char* format, ...);

int main()
{struct st{int age;char name[100];char sex[10];};struct st s = { 10,"xiaogang","boy" };FILE* pf = fopen("data.txt", "w");if (pf == NULL){perror("fopen");return 1;}fprintf(pf, "%d %s %s", s.age, s.name, s.sex);return 0;
}

6：fscanf

    int fscanf(FILE * stream, const char* format, ...);

int main()
{FILE* pf = fopen("data.txt","r");if (pf == NULL){perror("fopen");return 1;}int age;char name[100];char sex[100];fscanf(pf, "%d %s %s", &age, name, sex);printf("%d %s %s", age, name, sex);return 0;
}

7：fread和fwrite（二进制输入和输出）

ferad：    size_t fread(void* ptr, size_t size, size_t count, FILE * stream);

fwrite：    size_t fwrite(const void* ptr, size_t size, size_t count, FILE * stream);

int main()
{//fwriteFILE* pf = fopen("data.txt", "wb");if (pf == NULL){perror("fopen");return 1;}int arr[] = { 1,2,3,4,5,6,7,8,9 };fwrite(arr,sizeof(int),10,pf);fclose(pf);pf = NULL;//freadFILE* pf2 = fopen("data.txt", "rb");if (pf2 == NULL){perror("fopen");return 1;}int arr2[10] = { 0 };fread(arr2, sizeof(int), 10, pf2);for (int i = 0; i < 9; i++){printf("%d ",arr2[i]);}fclose(pf2);pf2 = NULL;return 0;
}

8:fseek

int fseek ( FILE * stream, long int offset, int origin );

int main()
{FILE* pFile;pFile = fopen("example.txt", "wb");fputs("This is an apple.", pFile);fseek(pFile, 9, SEEK_SET);fputs(" sam", pFile); fclose(pFile);return 0;
}

9:ftell

long int ftell ( FILE * stream );

#include <stdio.h>
int main ()
{FILE * pFile;long size;pFile = fopen ("myfile.txt","rb");if (pFile==NULL) perror ("Error opening file");else{fseek (pFile, 0, SEEK_END); // non-portablesize=ftell (pFile);fclose (pFile);printf ("Size of myfile.txt: %ld bytes.\n",size);}return 0;
}

10:rewind

让文件指针位置回到起始位置

int main()
{FILE* pFile;long size;pFile = fopen("example.txt", "rb");if (pFile == NULL)perror("Error opening file");else{fseek(pFile, 0, SEEK_END); // non-portablesize = ftell(pFile);printf("Size of example.txt: %ld bytes.\n", size);rewind(pFile);fseek(pFile, 0, SEEK_END); // non-portablesize = ftell(pFile);fclose(pFile);printf("Size of example.txt: %ld bytes.\n", size);}return 0;
}

11：feof（只能检测是否遇到文件末尾）