2022.11.10---进程

要求输入目录的路径后，能够打印出指定路径下所有文件的详细信息，类似ls -l

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#include <dirent.h>
#include <errno.h>
#include <time.h>
char file_type(mode_t m);
char *file_permission(mode_t m,char *str);
char *file_uid(uid_t uid,char *str);
char *file_gid(gid_t gid,char *str);
void file_time(time_t time);
int main(int argc, const char *argv[])
{
	DIR *dp=opendir(argv[1]);
	if(dp==NULL)

	{
		perror("opendir");
		return -1;
	}
	char ch=0;
	char str[20]="";
	struct stat buf;
	char path_name[50]="";
	while(1)
	{
		struct dirent *pa=readdir(dp);
		if(pa==NULL)
		{
			if(errno==0)
			{
				printf("read over\n");
				break;
			}
			else
			{
				perror("readdir");
				return -1;
			}
		}
		if(*pa->d_name!='.')
		{
			//printf("%s\n",pa->d_name);
			strcpy(path_name,argv[1]);
			strcat(path_name,pa->d_name);
			if(stat(path_name,&buf)<0)
			{
				perror("stat");
				return -1;
			}
			//提取文件类型
			ch=file_type(buf.st_mode);
			putchar(ch);
			//提取文件权限
			file_permission(buf.st_mode,str);
			printf("%s ",str);
			//提取链接数
			printf("%2ld ",buf.st_nlink);
			//提取所属用户ID  uid_t st_uid
			file_uid(buf.st_uid,str);
			printf("%s ",str);
			//提取所属组用户ID gid_t st_gid
			file_gid(buf.st_gid,str);
			printf("%s ",str);
			//提取文件大小  off_t st_size
			printf("%7ld ",buf.st_size);
			//提取文件时间 st_atime
			file_time((time_t)buf.st_mtime);
			printf("%s\n",pa->d_name);
		}
	}
	closedir(dp);
	
	return 0;
}
char file_type(mode_t m)
{
	char ch;
	switch(m&S_IFMT)
	{
	case S_IFBLK:ch='b';break;
	case S_IFCHR:ch='c';break;
	case S_IFDIR:ch='d';break;
	case S_IFREG:ch='-';break;
	case S_IFLNK:ch='l';break;
	case S_IFSOCK:ch='s';break;
	case S_IFIFO:ch='p';break;
	}
	return ch;
}
char *file_permission(mode_t m,char *str)
{
	for(int i=0;i<9;i++)
	{
		if(m&(0400>>i))
		{
			switch(i%3)
			{
			case 0:str[i]='r';break;
			case 1:str[i]='w';break;
			default:str[i]='x';
			}
		}
		else
		{
			str[i]='-';
		}
	}
	return str;
}
char *file_uid(uid_t uid,char *str)
{
	struct passwd *pa=getpwuid(uid);
	if(pa==NULL)
	{
		perror("getpwuid");
		return NULL;
	}
	strcpy(str,pa->pw_name);
	return str;
}
char *file_gid(gid_t gid,char *str)
{
	struct group *pa=getgrgid(gid);
	if(pa==NULL)
	{
		perror("getgrgid");
		return NULL;
	}
	strcpy(str,pa->gr_name);
	return str;
}
void file_time(time_t time)
{
	struct tm *pa=localtime(&time);
	printf("%02d %02d %02d:%02d ",pa->tm_mon+1,pa->tm_mday,\
			pa->tm_hour,pa->tm_min);
}

创建一个孤儿进程，创建一个僵尸进程；

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
int main(int argc, const char *argv[])
{
	pid_t pid=fork();
	if(pid>0)
	{
		printf("father\n");
		printf("getppid=%d getpid=%d\n",getppid(),getpid());
		_exit(7);//孤儿进程
		while(1)
			sleep(1);
	}
	else if(pid==0)
	{
		printf("child\n");
		printf("getppid=%d getpid=%d\n",getppid(),getpid());
		//_exit(7);//僵尸进程
		while(1)
			sleep(1);
	}
	else
	{
		perror("fork");
		return -1;
	}
	return 0;
}