可实现 a,l,r,R,i,s,t参数的任意组合
get_param函数:获取命令行输入中ls的参数，比如-l -al ......
int get_param(int argc,char**argv){
int param=PARAM_NONE,ar=0;
while(++ar<argc&&argv[ar][0]!='-');
for(int i=1;ar<argc&&i<strlen(argv[ar]);i++){
switch(argv[ar][i])
{
case 'a':param|=PARAM_A;break;
case 'l':param|=PARAM_L;break;
case 'r':param|=PARAM_r;break;
case 'R':param|=PARAM_R;break;
case 'i':param|=PARAM_I;break;
case 's':param|=PARAM_S;break;
case 't':param|=PARAM_T;break;
}
if(i==strlen(argv[ar])-1){
for(int j=ar+1;j<argc;j++){
if(argv[j][0]=='-'){
ar=j;
i=0;
printf(" a \n");
break;
}
}
}
}
return param;
}--------------------------------------------------------------------------------------------------------------------------------
display_l:对于-l参数进行单独设计
void display_l(struct stat*sta,const char*name){
DIR*dir;
mode_t mode_file=sta->st_mode;
if(S_ISLNK(mode_file))printf("l");
else if(S_ISREG(mode_file))printf("-");
else if(S_ISDIR(mode_file))printf("d");
else if(S_ISCHR(mode_file))printf("c");
else if(S_ISBLK(mode_file))printf("b");
else if(S_ISFIFO(mode_file))printf("f");
else if(S_ISSOCK(mode_file))printf("s");
if(S_IRUSR & mode_file){
printf("r");
}else printf("-");
if(S_IWUSR & mode_file){
printf("w");
}else printf("-");
if(S_ISUID & mode_file){
if(S_IXOTH & mode_file)
printf("s");
else printf("S");
}else if(S_IXUSR & mode_file){
printf("x");
}else printf("-");
if(S_IRGRP & mode_file){
printf("r");
}else printf("-");
if(S_IWGRP & mode_file){
printf("w");
}else printf("-");
if(S_ISGID & mode_file){
if(S_IXOTH & mode_file)
printf("s");
else printf("S");
}else if(S_IXGRP & mode_file){
printf("x");
}else printf("-");
if(S_IROTH & mode_file){
printf("r");
}else printf("-");
if(S_IWOTH & mode_file){
printf("w");
}else printf("-");
if(S_ISVTX & mode_file){
printf("T");
}else if(S_IXOTH & mode_file){
printf("x");
}else printf("-");
printf("%2ld ",sta->st_nlink);
printf("%4s ",getpwuid(sta->st_uid)->pw_name);
printf("%4s",getgrgid(sta->st_gid)->gr_name);
printf("%6ld",sta->st_size);
char time[32];
strcpy(time,ctime(&sta->st_mtime));//is mtime not atime
time[strlen(time)-1]='\0';
printf(" %.12s",time+4);
if(S_ISLNK(mode_file))printf("\033[36m %s\033[0m\n",name);
else if(S_ISDIR(mode_file))printf("\033[34m %s\033[0m\n",name);
else printf(" %s\n",name);-l参数实现中所需文件的信息都可以在stat结构体中找到
给字体加颜色可以使用 \033[xxm “输出内容” \033[0m 的形式
xx就是所对应颜色的编号，比如：
30 黑色
31 红色
32 绿色
33 黄色
34 蓝色
35 品红
36 青色
37 白色--------------------------------------------------------------------------------------------------------------------------------
ls_do函数:进行对指定目录下文件输出的主循环
void ls_do(const char*path,int mode){
DIR*dir_fd;
struct dirent*dir;
struct stat sta;
int total,ls_count=0;
char**ls_r=(char**)malloc(sizeof(char*)*MAX*MAX*MAX);
char**file_name=(char**)malloc(sizeof(char*)*MAX*MAX*MAX);
int count=0;
if((dir_fd=opendir(path))==NULL){
fprintf(stderr, "line: %d ",__LINE__);
perror("opendir");
free(ls_r);
free(file_name);
return;
//display_err("opendir",__LINE__);
}
printf("\033[33m%s:\033[0m\n",path);
while((dir=readdir(dir_fd))!=NULL){
if((dir->d_name)[0]=='.'&&(mode&PARAM_A)==0)continue;
file_name[count]=malloc(sizeof(char)*MAX*MAX);
strcpy(file_name[count],dir->d_name);
count++;
}
if(mode & PARAM_T)qsort(file_name,count,sizeof(file_name[0]),cmpt);
if(!(mode & PARAM_T)) qsort(file_name,count,sizeof(file_name[0]),cmp);
int i;
for((mode & PARAM_r)?(i=count-1):(i=0);(mode & PARAM_r)?(i>=0):(i<count);(mode & PARAM_r)?(i--):(i++)){
char*path_full=(char*)malloc(sizeof(char)*MAX*MAX);
if(!strcmp(path,"/"))sprintf(path_full,"/%s",file_name[i]);
else sprintf(path_full,"%s/%s",path,file_name[i]);
if(lstat(path_full,&sta)==-1){
//display_err(path,__LINE__);
fprintf(stderr, "line: %d ",__LINE__);
perror("opendir");
free(path_full);
free(file_name[i]);
free(ls_r);
free(file_name);
return;
}
if(mode & PARAM_I)printf("%ld ",sta.st_ino);
if(mode & PARAM_S)printf("%2ld ",sta.st_size?((sta.st_size/1024-1)/4+1)*4:0);
if(mode & PARAM_L)display_l(&sta,file_name[i]);
mode_t mode_file=sta.st_mode;
if(!(mode & PARAM_L)){
if(S_ISLNK(mode_file))printf("\033[36m%s \033[0m",file_name[i]);
else if(S_ISDIR(mode_file))printf("\033[34m%s \033[0m",file_name[i]);
else printf("%s ",file_name[i]);
}
if((mode & PARAM_R)&&!(S_ISLNK(sta.st_mode))&&S_ISDIR(sta.st_mode)&&(strcmp(file_name[i],".")*strcmp(file_name[i],".."))){
ls_r[ls_count]=(char*)malloc(sizeof(char)*MAX*MAX);
strcpy(ls_r[ls_count++],path_full);
}
free(file_name[i]);
free(path_full);
}printf("\n");
for(int i=0;i<ls_count;i++){
printf("\n\033[33m%s:\033[0m\n",ls_r[i]);
ls_do(ls_r[i],mode);
free(ls_r[i]);
}
ls_count=0;
if(!(mode & PARAM_L))printf("\b\b");
free(ls_r);
free(file_name);
closedir(dir_fd);
dir_fd=NULL;
}
while循环的作用是将当前所读目录下的所有文件名存放到数组中，并且记录下文件总数
之后的几行if else语句是为了对文件的输出顺序进行排序
之后的for循环是输出的重点(for循环头部实现了-r参数)：用心理解，相信你可以看懂，for循环最后会将目录文件的名称单独存入一个数组，之后进行递归遍历以实现-R参数(回想一下广度优先遍历)
你可能注意到了下面这段代码中有很多free语句
if(lstat(path_full,&sta)==-1){
fprintf(stderr, "line: %d ",__LINE__);
perror("opendir");
free(path_full);
free(file_name[i]);
continue;
}这是因为在遍历 / /var 等目录时，有时会因为权限问题访问失败，这时你不能直接终止程序，你要跳过这个文件，但每次循环内都会分配内存，所以要进行释放
---------------------------------------------------------------------------------------------------------------------------------
main函数只做一件事，就是将要读取的目录路径传给ls_do函数
int main(int argc,char**argv)
{
int i=1,mode=get_param(argc,argv);
char*path=(char*)malloc(sizeof(char)*MAX);
strcpy(path,"");
if(argc==1){//"ls"
ls_do(".",mode);
}else{
int sign=1;
for(i=1;i<argc;i++){
if(argv[i][0]=='-')continue;
else{
sign=0;
ls_do(argv[i],mode);
}
}
if(sign)ls_do(".",mode);
}
free(path);
return 0;
}--------------------------------------------------------------------------------------------------------------------------------
以下是完整程序示例：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pwd.h>
#include <sys/types.h>
#include <grp.h>
#include <time.h>
#define PARAM_NONE 0 //无参数
#define PARAM_A 1 //有参数a
#define PARAM_L 2 //有参数l
#define PARAM_r 4 //有参数r
#define PARAM_R 8 //有参数R
#define PARAM_I 16 //有参数i
#define PARAM_S 32 //有参数s
#define PARAM_T 64 //有参数t
#define MAX 128
int cmp(const void*,const void*);
int cmpt(const void*a,const void*b);
int get_param(int argc, char *argv[]);
void ls_do(const char*,int);
void display_l(struct stat*,const char*);// -l
int main(int argc,char**argv)
{
int i=1,mode=get_param(argc,argv);
char*path=(char*)malloc(sizeof(char)*MAX);
strcpy(path,"");
if(argc==1){//"ls"
ls_do(".",mode);
}else{
int sign=1;
for(i=1;i<argc;i++){
if(argv[i][0]=='-')continue;
else{
sign=0;
ls_do(argv[i],mode);
}
}
if(sign)ls_do(".",mode);
}
free(path);
return 0;
}
int cmp(const void*a,const void*b){
char**a1=(char**)a;
char**b1=(char**)b;
return strcmp(*a1,*b1);
}
int cmpt(const void*a,const void*b){
char**a1=(char**)a;
char**b1=(char**)b;
struct stat sta;
time_t t1,t2;
stat(*a1,&sta);
t1=sta.st_mtime;
stat(*b1,&sta);
t2=sta.st_mtime;
return t2-t1;
}
int get_param(int argc,char**argv){
int param=PARAM_NONE,ar=0;
while(++ar<argc&&argv[ar][0]!='-');
for(int i=1;ar<argc&&i<strlen(argv[ar]);i++){
switch(argv[ar][i])
{
case 'a':param|=PARAM_A;break;
case 'l':param|=PARAM_L;break;
case 'r':param|=PARAM_r;break;
case 'R':param|=PARAM_R;break;
case 'i':param|=PARAM_I;break;
case 's':param|=PARAM_S;break;
case 't':param|=PARAM_T;break;
}
if(i==strlen(argv[ar])-1){
for(int j=ar+1;j<argc;j++){
if(argv[j][0]=='-'){
ar=j;
i=0;
printf(" a \n");
break;
}
}
}
}
return param;
}
void display_err(const char *err_string,int line)
{
fprintf(stderr, "line: %d ", line);
perror(err_string);
exit(1);
}
void display_l(struct stat*sta,const char*name){
DIR*dir;
mode_t mode_file=sta->st_mode;
if(S_ISLNK(mode_file))printf("l");
else if(S_ISREG(mode_file))printf("-");
else if(S_ISDIR(mode_file))printf("d");
else if(S_ISCHR(mode_file))printf("c");
else if(S_ISBLK(mode_file))printf("b");
else if(S_ISFIFO(mode_file))printf("f");
else if(S_ISSOCK(mode_file))printf("s");
if(S_IRUSR & mode_file){
printf("r");
}else printf("-");
if(S_IWUSR & mode_file){
printf("w");
}else printf("-");
if(S_ISUID & mode_file){
if(S_IXOTH & mode_file)
printf("s");
else printf("S");
}else if(S_IXUSR & mode_file){
printf("x");
}else printf("-");
if(S_IRGRP & mode_file){
printf("r");
}else printf("-");
if(S_IWGRP & mode_file){
printf("w");
}else printf("-");
if(S_ISGID & mode_file){
if(S_IXOTH & mode_file)
printf("s");
else printf("S");
}else if(S_IXGRP & mode_file){
printf("x");
}else printf("-");
if(S_IROTH & mode_file){
printf("r");
}else printf("-");
if(S_IWOTH & mode_file){
printf("w");
}else printf("-");
if(S_ISVTX & mode_file){
printf("T");
}else if(S_IXOTH & mode_file){
printf("x");
}else printf("-");
printf("%2ld ",sta->st_nlink);
printf("%4s ",getpwuid(sta->st_uid)->pw_name);
printf("%4s",getgrgid(sta->st_gid)->gr_name);
printf("%6ld",sta->st_size);
char time[32];
strcpy(time,ctime(&sta->st_mtime));//is mtime not atime
time[strlen(time)-1]='\0';
printf(" %.12s",time+4);
if(S_ISLNK(mode_file))printf("\033[36m %s\033[0m\n",name);
else if(S_ISDIR(mode_file))printf("\033[34m %s\033[0m\n",name);
else printf(" %s\n",name);
}
void ls_do(const char*path,int mode){
DIR*dir_fd;
struct dirent*dir;
struct stat sta;
int total,ls_count=0;
char**ls_r=(char**)malloc(sizeof(char*)*MAX*MAX*MAX);
char**file_name=(char**)malloc(sizeof(char*)*MAX*MAX*MAX);
int count=0;
if((dir_fd=opendir(path))==NULL){
fprintf(stderr, "line: %d ",__LINE__);
perror("opendir");
free(ls_r);
free(file_name);
return;
//display_err("opendir",__LINE__);
}
printf("\033[33m%s:\033[0m\n",path);
while((dir=readdir(dir_fd))!=NULL){
if((dir->d_name)[0]=='.'&&(mode&PARAM_A)==0)continue;
file_name[count]=malloc(sizeof(char)*MAX*MAX);
strcpy(file_name[count],dir->d_name);
count++;
}
if(mode & PARAM_T)qsort(file_name,count,sizeof(file_name[0]),cmpt);
if(!(mode & PARAM_T)) qsort(file_name,count,sizeof(file_name[0]),cmp);
int i;
for((mode & PARAM_r)?(i=count-1):(i=0);(mode & PARAM_r)?(i>=0):(i<count);(mode & PARAM_r)?(i--):(i++)){
char*path_full=(char*)malloc(sizeof(char)*MAX*MAX);
if(!strcmp(path,"/"))sprintf(path_full,"/%s",file_name[i]);
else sprintf(path_full,"%s/%s",path,file_name[i]);
if(lstat(path_full,&sta)==-1){
//display_err(path,__LINE__);
fprintf(stderr, "line: %d ",__LINE__);
perror("opendir");
free(path_full);
free(file_name[i]);
free(ls_r);
free(file_name);
return;
}
if(mode & PARAM_I)printf("%ld ",sta.st_ino);
if(mode & PARAM_S)printf("%2ld ",sta.st_size?((sta.st_size/1024-1)/4+1)*4:0);
if(mode & PARAM_L)display_l(&sta,file_name[i]);
mode_t mode_file=sta.st_mode;
if(!(mode & PARAM_L)){
if(S_ISLNK(mode_file))printf("\033[36m%s \033[0m",file_name[i]);
else if(S_ISDIR(mode_file))printf("\033[34m%s \033[0m",file_name[i]);
else printf("%s ",file_name[i]);
}
if((mode & PARAM_R)&&!(S_ISLNK(sta.st_mode))&&S_ISDIR(sta.st_mode)&&(strcmp(file_name[i],".")*strcmp(file_name[i],".."))){
ls_r[ls_count]=(char*)malloc(sizeof(char)*MAX*MAX);
strcpy(ls_r[ls_count++],path_full);
}
free(file_name[i]);
free(path_full);
}printf("\n");
for(int i=0;i<ls_count;i++){
printf("\n\033[33m%s:\033[0m\n",ls_r[i]);
ls_do(ls_r[i],mode);
free(ls_r[i]);
}
ls_count=0;
if(!(mode & PARAM_L))printf("\b\b");
free(ls_r);
free(file_name);
closedir(dir_fd);
dir_fd=NULL;
}