ls.c

在linux9中实现查询显示的功能

#include <stdio.h>
#include <sys/stat.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <time.h>

void wenjian_leixing();
void wenjian_quanxian();
void wenjian_xinxi();
void shuchu_xinxi();

struct passwd  *usrinfo;
struct group   *gpinfo;
struct stat    statbuf;
char           wjlx;
char           wjqx[9];
int            lnum;
int            size;
time_t         lt;
char           str[30];

int main(int argc,char *argv[])
{
   DIR            *dp;
   char           buf[255];
   struct dirent  *dirp;
   int            i,j = 0;
   int            dir_name_len = 0;
   
   if(argc == 1)
   {
      getcwd(buf,255);
      if((dp=opendir(buf)) == NULL)
         printf("can't open %s",buf);
      while((dirp = readdir(dp)) != NULL)
      {
         if((strcmp(dirp->d_name,".")==0)||(strcmp(dirp->d_name,"..")==0))
            continue;
         if(lstat(dirp->d_name,&statbuf) < 0)
         {
             perror("lstat error!\n");
             continue;
         }
         if(j != 0&&j%5 == 0)
             printf("\n");
         j++;
         printf("%-16s",dirp->d_name);
      }
      printf("\n");
      closedir(dp);
      exit(0); 
   }
   else if(argc == 2&&(strcmp(argv[1],"-l") == 0))
   {
      getcwd(buf,255);
      if((dp=opendir(buf)) == NULL)
         printf("can't open %s",buf);
      while((dirp = readdir(dp)) != NULL)
      {
         if((strcmp(dirp->d_name,".")==0)||(strcmp(dirp->d_name,"..")==0))
            continue;
         if(lstat(dirp->d_name,&statbuf) < 0)
         {
            perror("lstat error!\n");
            continue;
         }
         wenjian_leixing();
         wenjian_quanxian();
         wenjian_xinxi();
         shuchu_xinxi();
         printf("  %s\n",dirp->d_name);
      }
      closedir(dp);
      exit(0); 
   }
   else if((strcmp(argv[1],"-l") == 0))
   { 
      for(i = 2;i < argc;i++)
      {
           if(lstat(argv[i],&statbuf)<0)
           {
              perror("lstat error!\n");
              continue;
           }
           if(!(S_ISDIR(statbuf.st_mode)))
           {
              wenjian_leixing();
              wenjian_quanxian();
              wenjian_xinxi();
              shuchu_xinxi();
              printf("  %s\n",argv[i]);
              printf("\n");
           }
           else 
           { 
              printf("%s\n",argv[i]); 
              if((dp=opendir(argv[i])) == NULL)
                 printf("can't open %s",argv[i]);
              while((dirp = readdir(dp)) != NULL)
              {
              if((strcmp(dirp->d_name,".")==0)||(strcmp(dirp->d_name,"..")==0))
                 continue;
              strcpy(buf,argv[i]);
              strcat(buf,"/");
              strcat(buf,dirp->d_name);
              if(lstat(buf,&statbuf) < 0)
              {
                 perror("lstat error\n");
                 continue;
              }
              wenjian_leixing();
              wenjian_quanxian();
              wenjian_xinxi();
              shuchu_xinxi();
              printf("  %s\n",dirp->d_name);
              }
              printf("\n");
              closedir(dp);
           }
      }
   }
   else
   { 
      for(i = 1;i < argc;i++)
      {
           if(lstat(argv[i],&statbuf)<0)
           {
              perror("lstat error!\n");
              continue;
           }
           if(!(S_ISDIR(statbuf.st_mode)))
           {
              printf("%s\n",argv[i]);
              printf("\n");
           }
           else 
           { 
              printf("%s\n",argv[i]); 
              if((dp=opendir(argv[i])) == NULL)
                 printf("can't open %s",argv[i]);
              while((dirp = readdir(dp)) != NULL)
              {
              if((strcmp(dirp->d_name,".")==0)||(strcmp(dirp->d_name,"..")==0))
                 continue;
              strcpy(buf,argv[i]);
              strcat(buf,"/");
              strcat(buf,dirp->d_name);
              if(lstat(buf,&statbuf) < 0)
              {
                 perror("lstat error\n");
                 continue;
              }
              printf("%s\n",dirp->d_name);
              }
              printf("\n");
              closedir(dp);
           }
      }
   }
}

void wenjian_leixing()
{
      /*biao shi wen jian lei xing*/
      if(S_ISREG(statbuf.st_mode))
         wjnx = '-';
      else if(S_ISDIR(statbuf.st_mode))
         wjnx = 'd';
      else if(S_ISCHR(statbuf.st_mode))
         wjnx = 'c';
      else if(S_ISBLK(statbuf.st_mode))
         wjnx = 'b';
      else if(S_ISLNK(statbuf.st_mode))
         wjnx = 'l';
}

void wenjian_quanxian()
{
      /*biao shi wen jian de quan xian*/
      if(statbuf.st_mode&S_IRUSR)
         wjqx[0]='r';
      else 
         wjqx[0]='-';
      if(statbuf.st_mode&S_IWUSR)
         wjqx[1]='w';
      else
         wjqx[1]='-';
      if(statbuf.st_mode&S_IXUSR)
         wjqx[2]='x';
      else
         wjqx[2]='-';
      if(statbuf.st_mode&S_IRGRP)
         wjqx[3]='r';
      else 
         wjqx[3]='-';
      if(statbuf.st_mode&S_IWGRP)
         wjqx[4]='w';
      else
         wjqx[4]='-';
      if(statbuf.st_mode&S_IXGRP)
         wjqx[5]='x';
      else
         wjqx[5]='-';
      if(statbuf.st_mode&S_IROTH)
         wjqx[6]='r';
      else 
         wjqx[6]='-';
      if(statbuf.st_mode&S_IWOTH)
         wjqx[7]='w';
      else 
         wjqx[7]='-';
      if(statbuf.st_mode&S_IXOTH)
         wjqx[8]='x';
      else 
         wjqx[8]='-';
}

void wenjian_xinxi()
{
      struct tm      *time;
      lnum = statbuf.st_nlink;
      size = statbuf.st_size;
      usrinfo = getpwuid(statbuf.st_uid);
      gpinfo = getgrgid(statbuf.st_gid);
      lt = statbuf.st_mtime;
      time = localtime(&lt);
      strftime(str,50,"%b  %d %R",time);
}

void shuchu_xinxi()
{
      int j;
      printf("%c",wjnx);
      for(j = 0;j < 9;j++)
         printf("%c",wjqx[j]);
      printf("    %d",lnum);
      if(usrinfo)
         printf(" %s",usrinfo->pw_name);
      if(gpinfo)
         printf("     %s",gpinfo->gr_name);
      printf("%13d ",size);
      printf(str);
}