custom_ls.c

c实现的cuntom ls

#include <stdio.h>
#include <ctype.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <unistd.h>
#include <memory.h>
#include <pwd.h>
#include <grp.h>

#ifdef PATH_MAX
static int pathmax = PATH_MAX;
#else
static int pathmax = 256;
#endif

//translate the bitPermision to the char presentation
char* GetPermisionMode(char *buf, mode_t mode)
{
char *psz = buf;
memset(buf, 0, sizeof buf);
if(S_ISREG(mode)) *psz++ = '-';
if(S_ISDIR(mode)) *psz++ = 'd';

if(S_IRUSR & mode) *psz++ = 'r';
else *psz++ = '-';
if(S_IWUSR & mode) *psz++ = 'w';
else *psz++ = '-';
if(S_IXUSR & mode) *psz++ = 'x';
else *psz++ = '-';

if(S_IRGRP & mode) *psz++ = 'r';
else *psz++ = '-';
if(S_IWGRP & mode) *psz++ = 'w';
else *psz++ = '-';
if(S_IXGRP & mode) *psz++ = 'x';
else *psz++ = '-';

if(S_IROTH & mode) *psz++ = 'r';
else *psz++ = '-';
if(S_IWOTH & mode) *psz++ = 'w';
else *psz++ = '-';
if(S_IXOTH & mode) *psz++ = 'x';
else *psz++ = '-';

*psz = '\0';
return buf;
}

//back to the upper directory
char* backone(char *dir)
{
char *temp = dir;
int  len = strlen(dir);
while(*(temp+len) != '/') {
	*(temp+len) = '\0';
	len--;
	}
*(temp+len) = '\0';
return dir;
}

/* print the file in a  directory */
void PrintContent(DIR *dp)
{
struct 	dirent	*dirCont;
while((dirCont = readdir(dp)) != NULL) {
if((! strcmp(dirCont -> d_name, ".")) || (! strcmp(dirCont -> d_name, "..")))
	continue;
fprintf(stderr, "%s\t", dirCont -> d_name);
}
fprintf(stdout, "\n\n");
}

/* recursive a directory */
void RecursiveDir(DIR *dp, char *psz)
{
DIR 		*pdp;
DIR 		*temp;
int		len;
struct dirent 	*dirpsz;
struct stat	statbuffer;
char 		fullpath[256];

len = strlen(psz);
*(psz + len) = '/';
*(psz +	len + 1) = '\0';

if((temp = opendir(psz)) == NULL) {
	fprintf(stderr, "can't open %s", psz);
	exit(1);
	}
/* print the file in the directory */
PrintContent(temp);

while((dirpsz = readdir(dp)) != NULL) {
if(! strcmp(dirpsz -> d_name, ".") || ! strcmp(dirpsz -> d_name, ".."))
	continue;

memset(fullpath, 0, sizeof fullpath);
strcpy(fullpath, psz);
strcat(fullpath, dirpsz -> d_name);
/* acquire the stat infomation about the file */ 
if(lstat(fullpath, &statbuffer)) {
	fprintf(stderr, "can not acquire the stat infomation\n");
	exit(1);
	}
/* judge the file whether is a directory */
if(S_ISDIR(statbuffer.st_mode)) {
	fprintf(stdout, "%s/\n", dirpsz -> d_name);
	if((pdp = opendir(fullpath)) == NULL) {
		fprintf(stderr, "can't open %s\n", dirpsz -> d_name);
		exit(1);
		}
	RecursiveDir(pdp, fullpath);
	closedir(pdp);
	}
}
}

//main function
int main(int argc, char **argv)
{
DIR  	*dp;
int	opt;
int 	optsum 	= 0;
int	flag 	= 1;
int	dflag 	= 0;
char 	*pstr;
char 	*pmode;
char 	psz[pathmax];
char 	*pfile;
char	mode[12];
char	dirName[pathmax];
struct 	stat statbuf;
struct 	dirent *dirp;
struct  passwd *puid;
struct  group  *pgid;

//get the option composition
if(argc == 1)
	optsum = 0;
else if(argc == 2 && argv[1][0] != '-')
	optsum = 100;
else if(argc == 2 && argv[1][0] == '-') {
	while((opt = getopt(argc, argv, "liadR")) != -1) {
		switch(opt){
			case 'l':
				optsum += 1;
				break;
			case 'i':
				optsum += 2;
				break;
			case 'a':
				optsum += 4;
				break;
			case 'R':
				optsum += 8;
				break;
			case 'd':
				optsum += 16;
				break;
			case '?':
				fprintf(stderr, "%s", "can not recognize the option\n");
                                exit(1);
			}
		}
	}
else if(argc == 3 && argv[1][0] == '-') {
	flag = 2;	//the flag which indicate whether have the parameter 
	while((opt = getopt(argc, argv, "liadR")) != -1) {
		switch(opt){
			case 'l':
				optsum += 1;
				break;
			case 'i':
				optsum += 2;
				break;
			case 'a':
				optsum += 4;
				break;
			case 'R':
				optsum += 8;
				break;
			case 'd':
				optsum += 16;
				break;
			case '?':
				fprintf(stderr, "%s", "can not recognize the option\n");
                                exit(1);
			}
		}
	}
else {
	fprintf(stderr, "%s", "the usage is wrong\n");
	exit(1);
}

memset(dirName, 0, sizeof dirName);
pstr = getcwd(dirName, pathmax);   //get the absolute path of the directory

if(flag == 1) {  //have no parameter
	dflag = 1;	//the flag indicate whether the parameter is a directory
	if((dp = opendir(pstr)) == NULL) {
		fprintf(stderr, "can't open %s", pstr);
		exit(1);
		}
	}
else if(flag == 2) {
	memset(psz, 0, sizeof psz);
	pfile = psz;
	strcpy(pfile, pstr);
	int leng = strlen(pfile);
	*(pfile + leng) = '/';	
	strcat(pfile, argv[2]);

//judge the parameter is a absolute path or a relative path
	if(lstat(pfile, &statbuf) < 0 && lstat(argv[2], &statbuf) < 0) {
		fprintf(stderr, "%s", "Don't have the file or directory\n");
		exit(1);
		}
	if(lstat(pfile, &statbuf) == 0) {
		if(S_ISDIR(statbuf.st_mode)) {
			dflag = 1;
			if((dp = opendir(pfile)) == NULL) {
				fprintf(stderr, "can't open %s", pfile);
				exit(1);
				}
			strcpy(pstr, pfile);
			}
		}
	else if(lstat(argv[2], &statbuf) == 0) {
		if(S_ISDIR(statbuf.st_mode)) {
			dflag = 1;
			if((dp = opendir(argv[2])) == NULL) {
				fprintf(stderr, "can't open %s", argv[2]);
				exit(1);
				}
			strcpy(pstr, argv[2]);
			}
		}
	}	


switch(optsum) {
	case 0:
		while((dirp = readdir(dp)) != NULL)
			if((strcmp(dirp->d_name, ".") != 0) && (strcmp(dirp->d_name, "..")) != 0)
				fprintf(stdout, "%s\n", dirp->d_name);
		break;
	case 1:
		if(dflag == 1) {
//the parameter is a directory,and indicate the file by reading the directory
			while((dirp = readdir(dp)) != NULL) {
				memset(psz, 0, sizeof psz);
				pfile = psz;
				strcpy(pfile, pstr);
				if((strcmp(dirp->d_name, "..")) == 0) {
					pfile = backone(psz);
					}
				else if(strcmp(dirp->d_name, ".") != 0) {
					int length = strlen(pfile);
					*(pfile + length) = '/';	
					strcat(pfile, dirp->d_name);
					}
				if(lstat(pfile, &statbuf) < 0) {
					fprintf(stderr, "can not acquire the stat infomation\n");
					exit(1);
					}
//get the char format permision mode and user name, group name, then print them
				pmode = GetPermisionMode(mode, statbuf.st_mode);
				puid = getpwuid(statbuf.st_uid);
				pgid = getgrgid(statbuf.st_gid);
				fprintf(stdout, "%s\t%d\t%s\t%s\t%d\t%.24s\t%s\n", 						pmode, statbuf.st_nlink, puid -> pw_name, 
						pgid -> gr_name, statbuf.st_size, 
						ctime(&statbuf.st_atime), 							dirp -> d_name);
				}
			}
//the parameter is a file
		else if(dflag == 0) {
			pmode = GetPermisionMode(mode, statbuf.st_mode);
			puid = getpwuid(statbuf.st_uid);
			pgid = getgrgid(statbuf.st_gid);
			fprintf(stdout, "%s\t%d\t%s\t%s\t%d\t%.24s\t%s\n", 					pmode, statbuf.st_nlink, puid -> pw_name, 
					pgid -> gr_name, statbuf.st_size, 
					ctime(&statbuf.st_atime), 						argv[2]);
			}
		break;
	case 2:
		if(dflag == 1) {
//the parameter is a directory,and indicate the file by reading the directory
		while((dirp = readdir(dp)) != NULL) {
			memset(psz, 0, sizeof psz);
			pfile = psz;
			strcpy(pfile, pstr);
			if(strcmp(dirp->d_name, "..") == 0 || strcmp(dirp -> d_name, ".") ==0) {
				continue;
				}
			else if(strcmp(dirp->d_name, ".") != 0) {
				int length = strlen(pfile);
				*(pfile + length) = '/';	
				strcat(pfile, dirp -> d_name);
				}
			if(lstat(pfile, &statbuf) < 0) {
				fprintf(stderr, "can not acquire the stat infomation\n");
				exit(1);
				}
			fprintf(stdout, "%d  %s\t", statbuf.st_ino, dirp -> d_name);
			}
		fprintf(stdout, "\n");
		}
		if(dflag == 0) {
			if(lstat(argv[2], &statbuf) < 0) {
			fprintf(stderr, "can not acquire the stat infomation\n");
			exit(1);
			}
		fprintf(stdout, "%d  %s\n", statbuf.st_ino, argv[2]);
		}	
		break;
	case 4:
		if(dflag == 1) {
//the parameter is a directory,and indicate the file by reading the directory
		while((dirp = readdir(dp)) != NULL) {
			fprintf(stdout, "%s\t", dirp -> d_name);
			}
		fprintf(stdout, "\n");
		}
		if(dflag == 0) {
			fprintf(stdout, "%d  %s\n", statbuf.st_ino, argv[2]);
		}			
		break;
	case 8:
		if(flag == 1) {
			fprintf(stdout, ".:\n");
			RecursiveDir(dp, pstr);
			break;
		}
		if(flag == 2 && dflag == 1) { //the command have parameter and the parameter is a 									directory
			fprintf(stdout, "%s\n", pstr);
			RecursiveDir(dp, pstr);
			break;
		}
		if(flag == 2 && dflag == 0) { //the command have parameter and the parameter is't 									a directory
			fprintf(stdout, "%s\n", argv[2]);
			break;
		}
	case 16:
		if(flag == 1)
			fprintf(stdout, ".\n");
		else
			fprintf(stdout, "%s\n", argv[2]);
		break;
	case 100:
		fprintf(stdout, "%s\n", argv[1]);
		break;
	}
return 0;
}