【二十六】 Linux网络编程——模仿linux的ls命令实现

【二十六】      Linux网络编程——模仿linux的ls命令实现

/*my_ls.c*/#include <stdio.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <time.h>#include <pwd.h>#include <grp.h>#include <dirent.h>int display_file(char *argv,char *fname){   struct stat buf;struct tm *tp;if (lstat(argv, &buf) < 0){perror("fail to lstat");return -1;}switch (buf.st_mode & S_IFMT){case S_IFSOCK :printf("s"); break;case S_IFLNK :printf("l"); break;case S_IFREG :printf("-"); break;case S_IFBLK :printf("b"); break;case S_IFDIR :printf("d"); break;case S_IFCHR :printf("c"); break;case S_IFIFO :printf("p"); break;}int n;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");}}else{printf("-");}}printf("%2d", buf.st_nlink);printf(" %s", getpwuid(buf.st_uid)->pw_name);printf(" %s", getgrgid(buf.st_gid)->gr_name);printf(" %8ld", buf.st_size);tp = localtime(&buf.st_mtime);printf(" %4d-%d-%d %2d:%2d", tp->tm_year+1900, tp->tm_mon+1, tp->tm_mday, tp->tm_hour, tp->tm_min);printf(" %s\n", fname);return 0;}int main(int argc,char *argv[]){    struct stat buf;    DIR *mydir;    struct dirent *dirp;    char path[256];if (argc < 2){printf("Usage : %s <file>\n", argv[0]);return -1;}    if(lstat(argv[1],&buf)<0)    {        perror("fail to lstat");        return -1;    }    if((buf.st_mode & S_IFMT)==S_IFDIR){        mydir=opendir(argv[1]);        while((dirp=readdir(mydir))!=NULL)        {               if(dirp->d_name[0]=='.') continue;            sprintf(path,"%s/%s",argv[1],dirp->d_name);            display_file(path,dirp->d_name);        }    }    else    {        display_file(argv[1],argv[1]);    }    return 0;}