zoukankan      html  css  js  c++  java
  • Linux find 命令的初步实现(C++)

    Implement a myfind command following the find command in UNIX operating system. The myfind command starts from the specified directory and recursively looks up the specified file. The command format is as follows:
    myfind PATH -option parameters
    PATH:The directory for looking up.
    -option parameters:
    -name “file”: Specify the name of the file to be found, which can have wildcard characters? *, etc
    -mtime n: Search by time, search for files modified n days before today
    -ctime n:Search by time for files created n days before today.
    Finally, output the search results to standard output.

    #include <stdio.h>
    #include <string.h>
    #include <getopt.h>
    #include <dirent.h>
    #include <time.h>
    #include <stdlib.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    
    int opterr = 0;
    char path[1024] = "";
    char targetname[100] = "";
    int modifiedtime = -1;
    int changetime = -1;
    
    char match(char *first, char *second) 
    {
        if (*first == '' && *second == '') 
            return 1; 
        if (*first == '*' && *(first+1) != '' && *second == '') 
            return 0; 
        if (*first == '?' || *first == *second) 
            return match(first+1, second+1); 
        if (*first == '*') 
            return match(first+1, second) || match(first, second+1); 
        return 0; 
    }
    
    char isFileOk(char *name, time_t mt, time_t ct){
        time_t now = time(0);
        int spd = 24*3600;
        int mtd = (now - mt)/spd;
        int ctd = (now - ct)/spd;
    
        //printf("filename: %s target: %s
    ", name, targetname);
        if(match(targetname, name) == 1){
            if(modifiedtime != -1 && mtd > modifiedtime) return 0;
            if(changetime != -1 && ctd > changetime) return 0;
            return 1;
        }
        return 0;
    }
    
    void findInDir(char *path) {
        DIR *d;
        struct dirent *dir;
        d = opendir(path);
        if (d) {
            while ((dir = readdir(d)) != NULL) {
                char newpath[1024];
                snprintf(newpath, sizeof(newpath), "%s/%s", path, dir->d_name);
                if (dir->d_type == DT_DIR) {
                    if (strcmp(dir->d_name, ".") == 0 || strcmp(dir->d_name, "..") == 0) continue;
                    findInDir(newpath);
                } else {
                    struct stat buf;
                    if(stat(newpath, &buf)==0){
                        if(isFileOk(dir->d_name, buf.st_mtime, buf.st_ctime)){
                            printf("%s/%s
    ", path, dir->d_name);
                        }
                    }
                }
            }
            closedir(d);
        }
    }
    
    int main(int argc, char *argv[]){
        char *optstr = "p:n:m:c:";
        struct option opts[] = {
            {"path", 1, NULL, 'p'},
            {"name", 1, NULL, 'n'},
            {"mtime", 1, NULL, 'm'},
            {"ctime", 1, NULL, 'c'},
            {0, 0, 0, 0},
        };
        int opt;
        while((opt = getopt_long(argc, argv, optstr, opts, NULL)) != -1){
            switch(opt) {
                case 'p':
                    strcpy(path, optarg);
                    break;
                case 'n':
                    strcpy(targetname, optarg);
                    break;
                case 'm':
                    modifiedtime = atoi(optarg);
                    break;
                case 'c':
                    changetime = atoi(optarg);
                    break;
                case '?':
                    if(strchr(optstr, optopt) == NULL){
                        fprintf(stderr, "unknown option '-%c'
    ", optopt);
                    }else{
                        fprintf(stderr, "option requires an argument '-%c'
    ", optopt);
                    }
                    return 1;
            }
        }
        findInDir(path);
        return 0;
    }
    
  • 相关阅读:
    [汇编与C语言关系]1.函数调用
    深入理解计算机系统
    设计模式
    深度探索C++对象模型
    More Effective C++
    MySQL必知必会
    数据结构与算法分析
    Java编程思想(后)
    Java编程思想(前十章)
    Java 入门
  • 原文地址:https://www.cnblogs.com/justsong/p/12219780.html
Copyright © 2011-2022 走看看