用不同语言来遍历目录和文件

最近翻移动硬盘，发现自己还短暂的写过两个月的perl语言，盘中赫然躺着一些perl脚本，其中一个便是实现的遍历目录及其包含的文件的脚本。
该功能无非就是利用递归来写代码，这里想用perl、python、shell和C语言分别对其进行编写，聊发少年狂而已。

1、程序列表

[root@localhost script]# ls -tlr
total 28
-rwxr--r--. 1 root root  276 May 17 19:16 shell_find.sh
-rwxr--r--. 1 root root  444 May 17 19:17 python_find.py
-rwxr--r--. 1 root root  782 May 17 19:18 perl_find.sh
-rw-r--r--. 1 root root 1184 May 17 19:36 C_Find.c
-rwxr-xr-x. 1 root root 9048 May 17 19:37 C_Find
[root@localhost script]# 

1.1 perl

#! /usr/bin/perl

use strict;

my @filelist;
my $dir = "../python";

push(@filelist,&findfile($dir));
print join("\n",@filelist);
print "\n";

sub findfile{
        my @filelist;
        my $dir = $_[0];
        opendir(DIR,$dir);
        my @temp = grep(!/^\.\.?$/,readdir(DIR));
        close(DIR);
        my $count = @temp;
        my $i; 
        my $tmpdir;
        for($i = 0; $i < $count; $i++){
                $tmpdir = (); 
                $tmpdir = "$dir/$temp[$i]";
                if(-d "$tmpdir"){
                        push(@filelist,$tmpdir);                                                                                                                                             
                        push(@filelist,&findfile("$tmpdir"));
                }   
                else {
                        push(@filelist,$tmpdir);
                }   
        }   
        return @filelist;   
}

1.2 python

#! /usr/bin/python3
# coding=utf-8

import os
basedir = '../python'
filelists = []

def find(basedir):
    global filelists
    for parent,dirnames,filenames in os.walk(basedir):
        for dirname in dirnames:
            filelists.append(os.path.join(parent,dirname))                                                                                                                                   
        for filename in filenames:
            filelists.append(os.path.join(parent,filename))

if __name__ == '__main__':
    find(basedir)
    print('\n'.join(filelists))

1.3 shell

#! /usr/bin/bash

set -o nounset
set -o errexit

function find(){
    for file in `ls $1`
    do  
        if [ -d $1"/"$file ]
        then
            echo $1"/"$file                                                                                                                                                                  
            find $1"/"$file
        else
            echo $1"/"$file
        fi  
    done
}

find "../python"

1.4 C

源代码：

/* list dir and files through C */                                                                                                                                                           

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>

#define MAX_PATH_LENGTH 512 

int find(char *path)
{
    DIR *ptr_dir;
    struct dirent *dir_entry;
    
    int i = 0;
    char *child_path;

    child_path = (char*)malloc(sizeof(char)*MAX_PATH_LENGTH);
    if(child_path == NULL){
        printf("malloc child_path occurs errors.\n");
        exit(1);
    }   
    
    memset(child_path,0x0,sizeof(char)*MAX_PATH_LENGTH);

    ptr_dir = opendir(path);
    while(( dir_entry = readdir(ptr_dir) ) != NULL){
        if(dir_entry->d_type & DT_DIR){
            if(strcmp(dir_entry->d_name,".") == 0 ||  
                    strcmp(dir_entry->d_name,"..") == 0){ 
                continue;
            }   
            sprintf(child_path,"%s/%s",path,dir_entry->d_name);
            printf("%s\n",child_path);
    
            find(child_path);
        } else {
            printf("%s/%s\n",path,dir_entry->d_name);
        }   
    }   
    
    free(child_path);
    child_path = NULL;

    return 0;
}
int main()
{
    find("../python");

    return 0;
}  

编译：

gcc -o C_Find C_Find.c

2、执行结果

上述代码执行结果一致，输出文件列表的默认排序或有差别。
以shell脚本的执行结果为例，输出如下：

[root@localhost script]# ./shell_find.sh 
../python/countCodeLine2.py
../python/countCodeLine.py
../python/countCodeLine.py_ori
../python/Django
../python/How_to_be_pythonic
../python/How_to_be_pythonic/add.c
../python/How_to_be_pythonic/adder.so
../python/How_to_be_pythonic/app_decrator.py
../python/How_to_be_pythonic/cpython_api.py
../python/How_to_be_pythonic/cpython_ctype.py
../python/How_to_be_pythonic/cpython_SWIG.py
../python/How_to_be_pythonic/debug.txt
../python/How_to_be_pythonic/decrator.py
../python/How_to_be_pythonic/def__.py
../python/How_to_be_pythonic/enumerate.py
../python/How_to_be_pythonic/exception.py
../python/How_to_be_pythonic/forelse.py
../python/How_to_be_pythonic/funccode1.py
../python/How_to_be_pythonic/Generators.py
../python/How_to_be_pythonic/kw-args.py
../python/How_to_be_pythonic/out.log
../python/How_to_be_pythonic/pprint.py
../python/How_to_be_pythonic/set.py
../python/How_to_be_pythonic/test3.py
../python/How_to_be_pythonic/test.py
[root@localhost script]# 

3、后记

1. C语言的实现方法中，有关dirent、stat等结构体含义的描述，可参见：
   http://www.360doc.com/content/15/0701/10/5470123_481878714.shtml
2. 代码中输出的是目录及文件，可调整。
3. 对列出的文件可做进一步的条件筛选，如后缀判断等。
4. 可比较时间，可优化。
5. 本文原作者:不出名的刀客，转载请一同转发本文链接。
6. 第一次网上写技术文，文有不对之处，欢迎指正。
7. 另，小白正在学习python，欢迎大神留言指教。