Question

我面临一个奇怪的问题，昨晚我正在做我的作业ls linux，代码在那里工作正常，现在当我在imac上测试时，它不起作用。它只读取当前目录，它不包含子目录。

#include <stdio.h>
#include <dirent.h>
#include <string.h>

#define GREEN "\x1b[32m"
#define BLUE "\x1b[34m"
#define WHITE "\x1b[37m"

void Usage() {
    fprintf(stderr, "\nUsage: exec [OPTION]... [DIR]...\n");
    fprintf(stderr, "List DIR's (directory) contents\n");
    fprintf(stderr, "\nOptions\n-R\tlist subdirectories recursively\n");
    return;
}

void RecDir(char * path, int flag) {
    DIR * dp = opendir(path);
    if(!dp) {
        perror(path);
        return;
    }
    struct dirent * ep;
    char newdir[512];
    printf(BLUE "\n%s :\n" WHITE, path);
    while((ep = readdir(dp)))
        if(strncmp(ep->d_name, ".", 1))
            printf(GREEN "\t%s" WHITE, ep->d_name);
    closedir(dp);
    dp = opendir(path);
    while((ep = readdir(dp))) if(strncmp(ep->d_name, ".", 1)) {
        if(flag && ep->d_type == 4) {
            sprintf(newdir, "%s/%s", path, ep->d_name);
            RecDir(newdir, 1);
        }
    }
    closedir(dp);
}

int main(int argc, char ** argv) {
    switch(argc) {
    case 2:
        if(strcmp(argv[1], "-R") == 0) 
            Usage();
        else 
            RecDir(argv[1], 0);
        break;
        case 3:
        if(strcmp(argv[1], "-R") == 0) 
            RecDir(argv[2], 1);
        else 
            Usage();
        break;
        default: 
            Usage();
    }
    return 0;
}

Answer 1

标志变量始终为0所以我在调用RecDir()函数时更改了它，以便它进入if块：

if(flag && ep->d_type == 4) {
            sprintf(newdir, "%s/%s", path, ep->d_name);
            printf("here:  %s\n",ep->d_name);
            RecDir(newdir, 1);
        }

并且能够递归调用RecDir()函数。

#include <stdio.h>
#include <dirent.h>
#include <string.h>

#define GREEN "\x1b[32m"
#define BLUE "\x1b[34m"
#define WHITE "\x1b[37m"

void Usage() {
    fprintf(stderr, "\nUsage: exec [OPTION]... [DIR]...\n");
    fprintf(stderr, "List DIR's (directory) contents\n");
    fprintf(stderr, "\nOptions\n-R\tlist subdirectories recursively\n");
    return;
}

void RecDir(char * path, int flag) {
    DIR * dp = opendir(path);
    if(!dp) {
        perror(path);
        return;
    }
    struct dirent * ep;
    char newdir[512];
    printf(BLUE "\n%s :\n" WHITE, path);
    while((ep = readdir(dp)))
        if(strncmp(ep->d_name, ".", 1))
            printf(GREEN "\t%s" WHITE, ep->d_name);
    closedir(dp);
    dp = opendir(path);
    while((ep = readdir(dp))) if(strncmp(ep->d_name, ".", 1)) {
        //printf("In While %d\n",flag);
        if(flag && ep->d_type == 4) {
            sprintf(newdir, "%s/%s", path, ep->d_name);
            printf("here:  %s\n",ep->d_name);
            RecDir(newdir, 1);
        }
    }
    closedir(dp);
}

int main(int argc, char ** argv) {
    switch(argc) {
    case 2:
        if(strcmp(argv[1], "-R") == 0) 
            Usage();
        else 
            //supplied flag=1 instead of 0, explained above.
            RecDir(argv[1], 1);
        break;
        case 3: 
        if(strcmp(argv[1], "-R") == 0) {
            RecDir(argv[2], 1);
        }
        else 
            Usage();
        break;
        default: 
            Usage();
    }
    return 0;
}

Answer 2

鉴于它是另一个操作系统，您首先需要确认d_type保存您认为它的值。在第一个循环中，作为调试，打印出d_type以及名称。

请注意，在第二个循环中，您第二次扫描目录以进入子目录时会遇到很多麻烦 - 然后在最后一秒决定不{i} flag是0 。为什么不对flag预先测试0而根本不再执行整个打开目录呢？

我实现ls的c代码，不能在mac上运行

2 个答案: