Question

我目前正在处理一个C程序问题，以便让我保持目录同步。它的主旨是：

如果文件位于目录A而不是目录B中，请将该文件复制到目录B。
如果文件同时位于目录A和目录B中，请将最新版本的文件复制到最旧版本的目录。
如果文件在目录B中但不在目录A中，请删除该文件。

我在获取需要打开和删除的文件的完整路径时遇到问题。所以我决定使用C函数chdir（path）。

我能够创建一个新文件并删除文件，但由于某种原因，即使在打开两个文件流之后，文件中的数据也不会被复制，我不知道为什么。代码肯定是凌乱的，但我无法弄清楚我哪里出错了。洞察力将不胜感激。我是C的新手，处理缓冲区和内存管理是我现在还不太擅长的事情。有什么想法吗？

#include "csapp.h"
#include <stdio.h>
#include <dirent.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>

// prototypes
bool inOtherDir(char*, char*);
void copyFile(char*, char*, char*, char*);
int isNewer(char*, char*, char*, char*);

int main(int argc, char **argv ) {

    // variables
    struct dirent *dirone;
    struct dirent *dirtwo;
    char* dirAPath = argv[1]; // this will be used for absolute paths
    char* dirBPath = argv[2];
    char cwd[256];
    char* cwdptr = cwd;

    // get the CWD for use later
    if(getcwd(cwd, sizeof(cwd)) == NULL) {
        perror("getcwd() error()");
        return 1;
    }

    // Testing
    // printf("CWD is: %s\n", cwd);

    if (argc < 3) {
        printf("Not enough arguments provided, please provide two directories.\n");
        return 1;
    }

    // open directory a
    DIR *ptrone = opendir(argv[1]);
    // open directory b
    DIR *ptrtwo = opendir(argv[2]);

    if (ptrone == NULL || ptrtwo == NULL) {
        printf("Could not open directory\n");
        return 1;
    }

    printf("Checking Sync Status: \n");
    // Open the directory and check to see if the file is a regular file
    // if it is regular, then do work on it based on if its in the other
    // directory or not.
    while ((dirone = readdir(ptrone)) != NULL) {
        if (dirone->d_type == DT_REG) {
            if(inOtherDir(dirone->d_name, argv[2])) {
                printf("File %s is in both directories.\n", dirone->d_name);
            } else {
                printf("File %s is in Directory A but not Directory B.\n", dirone->d_name);
                printf("Copying %s in Directory A to Directory B.\n",dirone->d_name);
                copyFile(dirone->d_name,dirAPath, dirBPath,cwdptr);
            }
        }
    }

    // check for files only in directory B, then delete them
    while ((dirtwo = readdir(ptrtwo)) != NULL) {
        if (dirtwo->d_type == DT_REG) {
            if(inOtherDir(dirtwo->d_name, argv[1])) {
                printf("File %s is in both directories.\n", dirtwo->d_name);
            } else {
                printf("File %s will be removed from the directory.\n",dirtwo->d_name);
                chdir(dirBPath);    
                remove(dirtwo->d_name);
                chdir(cwd);
            }
        }
    }
    closedir(ptrone);
    closedir(ptrtwo);
    return 0;
}

// Look through the directory to see if the same file is in there returns
// true if the file is in that directory and returns false if not.
bool inOtherDir(char* filename, char* direct)  {

    struct dirent *buf;
    DIR *directory = opendir(direct);

    if(directory == NULL) {
        printf("Could not open directory.");
        exit(1);
    }

    while((buf = readdir(directory)) != NULL) {
        if ((strcmp(filename, buf->d_name)) == 0) {
            return true;
        }
    }
    closedir(directory);
    return false;

}

// Copies the file from one directory to the other
void copyFile(char* filename, char* directory_from,char* directory_to, char* cwd) {

    FILE *file, *copyfile;
    char c;

    chdir(directory_from);
    file = fopen(filename,"r");
    if(file == NULL) {
        printf("Cannot open the file %s in copyFile.\n", filename);
    }
    chdir(cwd);
    chdir(directory_to);
    copyfile = fopen(filename, "w+");
    if(copyfile == NULL) {
        printf("Cannot open copy of the file %s in copyFile.\n", filename);
    }

    c = fgetc(file);
    while(c != EOF){
        fputc(c, copyfile);
        c = fgetc(file);
    }

    printf("Contents copied successfully.\n");

    fclose(file);
    fclose(copyfile);
    chdir(cwd);
    return;

}

无法将文件从目录A复制到目录B fopen（）

0 个答案: