lsl.c

Linux网络编程PPT和源码,供学习参考

#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <string.h>

void do_ls( char *,int );
void dostat( char *,char * );
void show_file_info( char *,struct stat *,char * );
void mode_to_letters( int,char * );
char * uid_to_name( uid_t );
char * gid_to_name( gid_t );

int main( int argc ,char *argv[] )
{
	if( argc==1 )
	{
		do_ls( ".",0 );	
	}
	else
	{
		if(!strcmp(argv[1],"-a"))
		{
			if(argc==3)
				do_ls( argv[2],0 );
			else if(argc==2)
				do_ls( ".",0 );
		}
		else if(!strcmp(argv[1],"-l"))
		{
			if(argc==3)
				do_ls( argv[2],1 );
			else if(argc==2)	
				do_ls( ".",1 );
		}
	}
	return 0;
}

void do_ls( char dirname[],int type )
{
	DIR * dir_ptr;
	struct dirent * direntp;
	char tmp[1024]={0};

	if ( (dir_ptr = opendir(dirname))==NULL )
		fprintf(stderr,"lsl : cannot open %s\n",dirname);
	else
	{
		while( (direntp = readdir(dir_ptr)) != NULL )
		{
			if(direntp->d_name[0]=='.')
				continue;
			if(type)
			{
				strcpy(tmp,dirname);
				strcat(tmp,"/");
				strcat(tmp,direntp->d_name);
				dostat( tmp,dirname );
				strcpy(tmp,"");
			}
			else
				printf("%s\n",direntp->d_name);
		}
			
		closedir(dir_ptr);
	}
}

void dostat( char * filename,char *dirname )
{
	struct stat info;
	if (stat(filename,&info)==-1)	
	{
		perror(filename);
	}
	else
		show_file_info(filename,&info,dirname);
}

void show_file_info(char *filename,struct stat * info_p,char *dirname)
{
	char modestr[11];

	mode_to_letters( info_p->st_mode,modestr );	
		
	printf("%s",modestr);
	printf("%4d ",(int)info_p->st_nlink);
	printf("%-8s",uid_to_name(info_p->st_uid));
	printf("%-8s",gid_to_name(info_p->st_gid));
	printf("%8ld ",(long)info_p->st_size);
	printf("%.12s ",4+ctime(&info_p->st_mtime));
	printf(" %s\n",filename+strlen(dirname)+1);
}

void mode_to_letters( int mode,char *str )
{
	strcpy(str,"----------");
	/* macro */
	if(S_ISDIR(mode)) str[0]='d';	/* directory */
	if(S_ISCHR(mode))	str[0]='c'; /* char devices */
	if(S_ISBLK(mode)) str[0]='b'; /* block device */

	if( mode&S_IRUSR ) str[1]='r';	/* 3 bit for user */
	if( mode&S_IWUSR ) str[2]='w';
  if ( (mode & S_ISUID) && (mode & S_IXUSR) )
		str[3] = 's';
  else if ( (mode & S_ISUID) && !(mode & S_IXUSR) )
		str[3] = 'S';
  else if ( mode & S_IXUSR ) 
		str[3] = 'x';

	if( mode&S_IRGRP ) str[4]='r';	/* 3 bit for group */
	if( mode&S_IWGRP ) str[5]='w';
  if ( (mode & S_ISGID) && (mode & S_IXGRP) )
		str[6] = 's';
  else if ( (mode & S_ISGID) && !(mode & S_IXGRP) )
		str[6] = 'S';
  else if ( mode & S_IXGRP ) 
		str[6] = 'x';

	if( mode&S_IROTH ) str[7]='r';	/* 3 bit for other */
	if( mode&S_IWOTH ) str[8]='w';
  if ( (mode & S_ISVTX) && (mode & S_IXOTH) )
		str[9] = 't';
  else if ( (mode & S_ISVTX) && !(mode & S_IXOTH) )
		str[9] = 'T';
  else if ( mode & S_IXOTH ) 
		str[9] = 'x';

}

#include <pwd.h>
char * uid_to_name(uid_t uid)
{
	struct passwd *pw_ptr;
	static char numstr[10];

	if((pw_ptr=getpwuid(uid))==NULL)
	{
		sprintf(numstr,"%d",uid);
		return numstr;
	}
	else 
		return pw_ptr->pw_name;
}
#include <grp.h>

char * gid_to_name(gid_t gid) 
{
	struct group *grp_ptr;
	static char numstr[10];
	
	if((grp_ptr=getgrgid(gid))==NULL)
	{
		sprintf(numstr,"%d",gid);
		return numstr;
	}
	else
		return grp_ptr->gr_name;
}