文件FILE写入与读取

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一，介绍fgetc，fputc是一个一个字符串读取的

/*************************************************************************    > File Name:    > Author: songli    > QQ:2734030745    > Mail: 15850774503@163.com    > Created Time: ************************************************************************/#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <stdlib.h>#include <string.h>int main(int argc, char *argv[]){    printf("请您输入文件的路径：\n");    char filename1[50], filename2[50], ch;    scanf("%s", filename1);    FILE *in = fopen(filename1, "rb");   //以读的方式打开filename1    if (!in)        return -1;    printf("请您输入文件的路径：\n");    scanf("%s", filename2);    FILE *out = fopen(filename2, "wb");//以写的方式打开filename2    if (!out)        return -1;    while ((ch = fgetc(in)) != EOF)    {        fputc(ch, out);        printf("%c", ch);    }    fclose(in);    fclose(out);    printf("\n");    system("pause");    return EXIT_SUCCESS;}

二，一行一行读取文件fgets和fputs

文本格式读写的
函数原型

       int fgetc(FILE *stream);       char *fgets(char *s, int size, FILE *stream);

实际例子：

/*************************************************************************> File Name:> Author: songli> QQ:2734030745> Mail: 15850774503@163.com> Created Time:************************************************************************/#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <stdlib.h>#include <string.h>int main(int argc, char *argv[]){    printf("请您输入文件的路径：\n");    char filename1[50], filename2[50];    //在堆上开辟内存1kb    char *buf = (char*)malloc(sizeof(char) * 1024);     scanf("%s", filename1);    FILE *in = fopen(filename1, "rb");    if (!in)        return -1;    printf("请您输入文件的路径：\n");    scanf("%s", filename2);    FILE *out = fopen(filename2, "wb");    if (!out)        return -1;    while (!feof(in))    {        fgets(buf, sizeof(char) * 1024, in);        //写的文件中        fputs(buf, out);    }    //释放内存    free(buf);    fclose(in);    fclose(out);    printf("\n");    system("pause");    return EXIT_SUCCESS;}

三，格式化输入和输出fscanf和fprintf的函数

函数模型

       #include <stdio.h>       int scanf(const char *format, ...);       int fscanf(FILE *stream, const char *format, ...);       int sscanf(const char *str, const char *format, ...);

/*************************************************************************> File Name:> Author: songli> QQ:2734030745> Mail: 15850774503@163.com> Created Time:************************************************************************/#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <stdlib.h>#include <string.h>int main(int argc, char *argv[]){    printf("请您输入文件的路径：\n");    char filename1[50], filename2[50];    scanf("%s", filename1);    FILE *in = fopen(filename1, "rb");    if (!in)        return -1;    printf("请您输入文件的路径：\n");    scanf("%s", filename2);    FILE *out = fopen(filename2, "wb");    if (!out)        return -1;    int a, b;    char c;    while (!feof(in))    {        //这边我就简单写一下   可以用开辟堆上的内存的指针操作        fscanf(in, "%d%c%d=\n", &a, &c, &b);        printf("%d,%c，%d\n", a, c, b);        //写入一个文件中        fprintf(out, "%d%c%d=\n", a, c, b);    }    fclose(in);    fclose(out);    printf("\n");    system("pause");    return EXIT_SUCCESS;}

效果图
这里写图片描述

四，文件随机读写好的函数fseek和ftell的使用

函数

       int fseek(FILE *stream, long offset, int whence); //SEEK_SET, SEEK_CUR, SEEK_END       long ftell(FILE *stream);       void rewind(FILE *stream);       int fgetpos(FILE *stream, fpos_t *pos);       int fsetpos(FILE *stream, const fpos_t *pos);

五，文件的拷贝和切割fread和fwrite

函数的定义

#include <stdio.h>       size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);       size_t fwrite(const void *ptr, size_t size, size_t nmemb,                     FILE *stream);

例子：

/*************************************************************************> File Name:> Author: songli> QQ:2734030745> Mail: 15850774503@163.com> Created Time:************************************************************************/#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <stdlib.h>#include <string.h>int main(int argc, char *argv[]){    printf("请您输入文件的路径：\n");    char filename1[50], filename2[50];    //在堆上开辟内存1kb    char *buf = (char*)malloc(sizeof(char) * 1024);    scanf("%s", filename1);    FILE *in = fopen(filename1, "rb");    if (!in)        return -1;    printf("请您输入文件的路径：\n");    scanf("%s", filename2);    FILE *out = fopen(filename2, "wb");    if (!out)        return -1;    while (!feof(in))    {        int len = fread(buf, sizeof(char), 1024, in);        fwrite(buf, sizeof(char), len, out);    }    //释放内存    free(buf);    fclose(in);    fclose(out);    printf("\n");    system("pause");    return EXIT_SUCCESS;}

效果图
这里写图片描述

这里我要讲的fread函数的
的参数的返回值是读取的到数据的大小

int len = fread(buf, sizeof(char), 1024, in);

六，文件的信息的函数stat

 #include <sys/types.h>       #include <sys/stat.h>       #include <unistd.h>       int stat(const char *pathname, struct stat *buf);       int fstat(int fd, struct stat *buf);       int lstat(const char *pathname, struct stat *buf);       #include <fcntl.h>           /* Definition of AT_* constants */ struct stat {               dev_t     st_dev;         /* ID of device containing file */               ino_t     st_ino;         /* inode number */               mode_t    st_mode;        /* protection */               nlink_t   st_nlink;       /* number of hard links */               uid_t     st_uid;         /* user ID of owner */               gid_t     st_gid;         /* group ID of owner */               dev_t     st_rdev;        /* device ID (if special file) */               off_t     st_size;        /* total size, in bytes */               blksize_t st_blksize;     /* blocksize for filesystem I/O */               blkcnt_t  st_blocks;      /* number of 512B blocks allocated */               /* Since Linux 2.6, the kernel supports nanosecond                  precision for the following timestamp fields.                  For the details before Linux 2.6, see NOTES. */               struct timespec st_atim;  /* time of last access */               struct timespec st_mtim;  /* time of last modification */               struct timespec st_ctim;  /* time of last status change */           #define st_atime st_atim.tv_sec      /* Backward compatibility */           #define st_mtime st_mtim.tv_sec           #define st_ctime st_ctim.tv_sec           };