linux下c语言完成定制自己的ls命令（至少使用三种参数）

linux下c语言完成定制自己的ls命令（至少使用三种参数）

2018-07-06 20:23:45 q_2478857829 阅读数 352更多

分类专栏： linux入门

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本文链接：https://blog.csdn.net/qq_38146797/article/details/80945840

定制自己的ls命令，要求提供至少三种参数，对应三种不同的输出方式。

源码如下：

    #include <sys/types.h>  
    #include <sys/stat.h>  
    #include <unistd.h> 
    #include <stdio.h>  
    #include <string.h>  
    #include <errno.h>  
    #include <pwd.h>  
    #include <grp.h>  
    #include <time.h>  
    #include <dirent.h>  
    int  fun1(char *dir,char *filename,int lflag)  
    {  
        int n;
        struct stat buf;  
        char out[100];  
     //   struct passwd *pw;
      //  struct group *gr;
        struct tm *t;
        if (lflag==0)
        {
            printf("%s\t",filename);
            return 0;
        }
        if(lstat(dir,&buf)<0)
        {
            fprintf(stderr,"stat error:%s\n",strerror(errno));
            return -1;
        }
      
        switch(buf.st_mode & S_IFMT)  
        {  
        case S_IFLNK:     
            printf("l");  
            break;  
        case S_IFSOCK:    
            printf("s");  
            break;  
        }  
       
        for(n=8;n>=0;n--)  
        {  
            if(buf.st_mode&(1<<n))  
            {  
                switch(n%3)  
                {  
                case 2:  
                    printf("r");  
                    break;  
                case 1:  
                    printf("w");  
                    break;  
                case 0:  
                    printf("x");  
                        break;  
                default:  
                    break;  
      
                }  
            }  
            else  
            {  
                printf("-");  
            }  
        }  
          
          
        printf(" %d",buf.st_nlink); 
        struct passwd *pw;   
        pw = getpwuid(buf.st_uid);  
        printf(" %s",pw->pw_name);  
        struct group *gr;
        gr = getgrgid(buf.st_gid);  
        printf(" %s",gr->gr_name);  
      
        printf(" %ld",buf.st_size);  
          
        
        t = localtime(&buf.st_atime);  
        printf(" %d-%d-%d %d:%d",t->tm_year+1900,  t->tm_mon+1,  t->tm_mday,  t->tm_hour,   t->tm_min);  
       printf(" %s ",filename);   
      
          
             
        if(S_ISLNK(buf.st_mode))  
        {  
            printf(" -> ");  
            if(readlink(filename,out,100)==-1)  
            {  
      
            }  
            printf("%s",out);  
      
        }  
        printf("\n");  
        return 0;  
    }
    int ls_prepare(char *w,int aflag,int lflag){
        struct stat buf;
        char name[100];
        DIR *dir;
        struct dirent *pdr;
        if(lstat(w,&buf)<0)  
        {  
            fprintf(stderr,"stat error:%s\n",strerror(errno));  
            return -1;  
        }  
          
        if(S_ISDIR(buf.st_mode))  
        {  
            DIR *dir;  
            dir = opendir(w);  
            struct dirent *pdr;  
            while ((pdr = readdir(dir))!=NULL)  
            {  
                if(aflag==0)
                 {
                    if(pdr->d_name[0]=='.')  
                        continue; 
                    memset(name,0,100);  
                    strcpy(name,w);  
                    strcat(name,"/");  
                    strcat(name,pdr->d_name);  
                    fun1(name,pdr->d_name,lflag);
                    }else
                    {

                    memset(name,0,100);  
                    strcpy(name,w);  
                    strcat(name,"/");  
                    strcat(name,pdr->d_name);  
                    fun1(name,pdr->d_name,lflag); 
                    } 
                }
                closedir(dir);
            }
            else
            {
                fun1(w,w,lflag);
            }
            return 0;
        }

      
    int main(int argc ,char **argv)  
    {  
       int aflag=0;
       int lflag=0;
       char c;
       int i;
       while((c=getopt(argc,argv,"al"))!=-1)
       {
        switch(c)
        {
            case 'a':aflag=1;break;
            case 'l':lflag=1;break;
            default:break;
        }
       }
       if (argc==optind)
       {
        ls_prepare("./",aflag,lflag);
       }
       else
       {
        for(i=optind;i<argc;i++)
            ls_prepare(argv[i],aflag,lflag);
       }
       printf("\n");
       return 0;
    }  

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