linux c類比ls命令詳解

本篇文章是對linux中基於c類比ls命令的實現方法進行了詳細的分析介紹，需要的朋友參考下 複製代碼 代碼如下:

/*
類比ls命令，實現參數-tariRl.有些代碼重複出現，可改進
可以在該程式的基礎上增加參數，該程式思路清晰，容易擴充
*/
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<sys/types.h>
#include<unistd.h>
#include<sys/stat.h>
#include<dirent.h>
#include<sys/ioctl.h>
#include<pwd.h>
#include<grp.h>
#define LL (1<<0) /*帶l參數標誌*/
#define IL (1<<1) /*帶i參數標誌*/
#define RU (1<<2) /*帶R參數標誌*/
#define TL (1<<16) /*帶t參數標誌*/
#define AL (1<<17) /*帶a參數標誌*/
#define RL (1<<18) /*帶r參數標誌*/
#define LENGTH 500 /*字串最大長度*/
#define MAX_FILE_COUNT 500/*檔案清單最大長度*/
/*函式宣告*/
void error(char* error_message,int line);
void display(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode);
int file_list(char* path,struct stat* stalist,char (*namelist)[LENGTH],int mode);
void display_simply(char (*namelist)[LENGTH],int n);
void display_LL(struct stat * stalist,char (*namelist)[LENGTH],int n);
void display_IL(struct stat * stalist,char (*namelist)[LENGTH],int n);
void display_LL_IL(struct stat * stalist,char (*namelist)[LENGTH],int n);
void display_RU(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode);
void display_RU_LL(struct stat * stalist,char (*namelist)[LENGTH],int n,int mode);
void display_RU_IL(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode);
void display_RU_IL_LL(struct stat * stalist,char (*namelist)[LENGTH],int n,int mode);
/*主函數*/
int main(int argc,char **argv)
{
int i,j;
/*mode的前16個位用來標誌那些能影響顯示的參數，16位之後的位用來標誌不影響輸出格式的參數。這個程式只用到了0-3位，16-18位，如果要在該程式的基礎上增加參數，可以用其他沒有使用的位。
mode的第0位為1表示帶l參數，mode的第1位為1表示帶i參數，mode的第2位為1表示帶R參數，mode的第16位為1表示帶t參數，mode的第17位為1表示帶a參數，mode的第18位為1表示帶r參數*/
int mode=0;
char error_message[LENGTH]={0};/*錯誤資訊*/
char path[LENGTH]={0};/*路徑*/
struct stat stalist[MAX_FILE_COUNT];/*檔案詳細資料數組*/
char namelist[MAX_FILE_COUNT][LENGTH];/*檔案名稱數組*/
int flag=0;/*判斷是否指定了目錄*/
int count;/*檔案個數*/
/*解析參數*/
for(i=1;i<argc;i++){
if(argv[i][0]=='-'){/*如果是選項參數*/
for(j=1;j<strlen(argv[i]);j++){
if(argv[i][j]=='l')
mode=mode|LL;
else if(argv[i][j]=='i')
mode=mode|IL;
else if(argv[i][j]=='R')
mode=mode|RU;
else if(argv[i][j]=='r')
mode=mode|RL;
else if(argv[i][j]=='a')
mode=mode|AL;
else if(argv[i][j]=='t')
mode=mode|TL;
else{
snprintf(error_message,LENGTH,"no option of %c",argv[i][j]);
error(error_message,__LINE__);
}
}
}else{/*參數為目錄或檔案*/
if(flag==1)
error("can not specify more then two dir or file",__LINE__);
else
flag=1;
if(argv[i][0]!='/'){/*相對路徑*/
strcat(path,get_current_dir_name());
strcat(path,"/");
strncat(path,argv[i],strlen(argv[i]));
}else/*絕對路徑*/
strcpy(path,argv[i]);
}
}
if(flag==0)/*未指定任何目錄或檔案,則使用預設目前的目錄*/
strcat(path,get_current_dir_name());
/*根據mode擷取指定目錄下的檔案*/
count=file_list(path,stalist,namelist,mode);

/*根據mode顯示檔案*/
display(stalist,namelist,count,mode);
return 0;
}
/*擷取檔案清單*/
int file_list(char* path,struct stat* stalist,char (*namelist)[LENGTH],int mode)
{
int i=0,index,j,k;
DIR *dir;
struct dirent *ptr;
char str[LENGTH];
char nametemp[LENGTH];
struct stat statemp;
if(stat(path,&stalist[0])<0){
// puts(path);
error("the specify file is not exist",__LINE__);
}
if(S_ISDIR(stalist[0].st_mode)){/*如果該路徑指向的是一個目錄*/
if((dir=opendir(path))==NULL){/*開啟目錄*/
sprintf(str,"can not open %s",path);
error(str,__LINE__);
}
chdir(path);/*改變當前工作目錄到path*/
i=0;
while((ptr=readdir(dir))!=NULL){/*依次讀取目錄下的所有檔案*/
if(ptr->d_name[0]=='.' && !(mode & AL))/*忽略隱藏檔案*/
continue;
/*按字母順序插入到stalist數組及namelist數組*/
for(j=i;j>0;j--){
if(strcmp(ptr->d_name,namelist[j-1])>0)
break;
}
for(k=i;k>j;k--){
strcpy(namelist[k],namelist[k-1]);
stalist[k]=stalist[k-1];
}
strcpy(namelist[j],ptr->d_name);
stat(ptr->d_name,&stalist[j]);
i++;
if(i==MAX_FILE_COUNT)
error("file count beyond MAX_FILE_COUNT",__LINE__);
}
closedir(dir);
}else{
j=strlen(path)-1;
while(j>=0 && path[j]!='/'){
j--;
}
if(j<0)
error("path error",__LINE__);
j++;
k=0;
while(path[j]){
namelist[0][k]=path[j];
j++;
k++;
}
namelist[0][k]=0;
return 1;
}
if(mode & TL){/*按檔案修改時間排序*/
for(j=0;j<i;j++){
index=j;
for(k=j+1;k<i;k++)
if(stalist[index].st_mtime<stalist[k].st_mtime){
index=k;
}
statemp=stalist[j];
stalist[j]=stalist[index];
stalist[index]=statemp;
strcpy(nametemp,namelist[j]);
strcpy(namelist[j],namelist[index]);
strcpy(namelist[index],nametemp);
}
}
if(mode & RL){/*反序排列*/
for(j=0;j<i/2;j++){
strcpy(nametemp,namelist[j]);
strcpy(namelist[j],namelist[i-j-1]);
strcpy(namelist[i-j-1],nametemp);
statemp=stalist[j];
stalist[j]=stalist[i-j-1];
stalist[i-j-1]=statemp;
}
}
return i;
}
/*根據mode選擇不同的函數進行顯示*/
void display(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode)
{
/*使mode的高16位為0*/
int m = mode & ((1<<16)-1);
switch(m){
case 0:
display_simply(namelist,n);
break;
case 1:
display_LL(stalist,namelist,n);
break;
case 2:
display_IL(stalist,namelist,n);
break;
case 3:
display_LL_IL(stalist,namelist,n);
break;
case 4:
display_RU(stalist,namelist,n,mode);
break;
case 5:
display_RU_LL(stalist,namelist,n,mode);
break;
case 6:
display_RU_IL(stalist,namelist,n,mode);
break;
case 7:
display_RU_IL_LL(stalist,namelist,n,mode);
break;
}
}
/*不帶顯示選項，簡單顯示檔案名稱*/
void display_simply(char (*namelist)[LENGTH],int n)
{
int i,maxlength=0,cols;
struct winsize ts;
for(i=0;i<n;i++)
if(strlen(namelist[i])>maxlength)
maxlength=strlen(namelist[i]);
/*擷取終端的大小*/
ioctl(STDIN_FILENO,TIOCGWINSZ,&ts);
cols=ts.ws_col;
cols/=(maxlength+1);
//lines=ts.ws_row;
for(i=0;i<n;i++){
if(i!=0 && i%cols==0)
puts("");
printf("%*s",-(maxlength+1),namelist[i]);
}
putchar('n');
}
/*-l 參數，顯示詳細檔案資訊*/
void display_LL(struct stat * stalist,char (*namelist)[LENGTH],int n)
{
int i,mode;
char* str;
for(i=0;i<n;i++){
mode=stalist[i].st_mode;
if(S_ISDIR(mode))
printf("d");
else
printf("-");
if(mode & (1<<8))
printf("r");
else
printf("-");
if(mode & (1<<7))
printf("w");
else
printf("-");
if(mode & (1<<6))
printf("x");
else
printf("-");
if(mode & (1<<5))
printf("r");
else
printf("-");
if(mode & (1<<4))
printf("w");
else
printf("-");
if(mode & (1<<3))
printf("x");
else
printf("-");
if(mode & (1<<2))
printf("r");
else
printf("-");
if(mode & (1<<1))
printf("w");
else
printf("-");
if(mode & (1<<0))
printf("x");
else
printf("-");
printf(" %-3d",stalist[i].st_nlink);
printf(" %-6s",getpwuid(stalist[i].st_uid)->pw_name);
printf(" %-6s",getgrgid(stalist[i].st_gid)->gr_name);
printf(" %-10d",stalist[i].st_size);
str=ctime(&stalist[i].st_mtime);
str[strlen(str)-2]=0;
printf(" %s",str);
printf(" %sn",namelist[i]);
}
}
/*-i 參數，顯示檔案名稱及節點號*/
void display_IL(struct stat* stalist,char (*namelist)[LENGTH],int n)
{
int i,maxlength=0,cols;
struct winsize ts;
for(i=0;i<n;i++)
if(strlen(namelist[i])>maxlength)
maxlength=strlen(namelist[i]);
/*擷取終端的大小*/
ioctl(STDIN_FILENO,TIOCGWINSZ,&ts);
cols=ts.ws_col;
cols/=(maxlength+9);
//lines=ts.ws_row;

for(i=0;i<n;i++){
if(i!=0 && i%cols==0)
puts("");
printf("%-8d ",stalist[i].st_ino);
printf("%*s",-(maxlength+1),namelist[i]);
}
putchar('n');
}
/*-li 參數，顯示詳細檔案資訊和節點號*/
void display_LL_IL(struct stat * stalist,char (*namelist)[LENGTH],int n)
{
int i,mode;
char* str;
for(i=0;i<n;i++){
printf("%-8d ",stalist[i].st_ino);
mode=stalist[i].st_mode;
if(S_ISDIR(mode))
printf("d");
else
printf("-");
if(mode & (1<<8))
printf("r");
else
printf("-");
if(mode & (1<<7))
printf("w");
else
printf("-");
if(mode & (1<<6))
printf("x");
else
printf("-");
if(mode & (1<<5))
printf("r");
else
printf("-");
if(mode & (1<<4))
printf("w");
else
printf("-");
if(mode & (1<<3))
printf("x");
else
printf("-");
if(mode & (1<<2))
printf("r");
else
printf("-");
if(mode & (1<<1))
printf("w");
else
printf("-");
if(mode & (1<<0))
printf("x");
else
printf("-");
printf(" %-3d",stalist[i].st_nlink);
printf(" %-6s",getpwuid(stalist[i].st_uid)->pw_name);
printf(" %-6s",getgrgid(stalist[i].st_gid)->gr_name);
printf(" %-10d",stalist[i].st_size);
str=ctime(&stalist[i].st_mtime);
str[strlen(str)-2]=0;
printf(" %s",str);
printf(" %sn",namelist[i]);

}
}
/*-R 參數，簡單顯示所有檔案，包括目錄下面的子目錄*/
void display_RU(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode)
{
int i,count;
char path[LENGTH]={0},temp[LENGTH]={0};
struct stat sta[MAX_FILE_COUNT];
char name[MAX_FILE_COUNT][LENGTH];
puts(get_current_dir_name());
display_simply(namelist,n);
putchar('n');
strcpy(path,get_current_dir_name());

for(i=0;i<n;i++){
if(strcmp(namelist[i],".")==0 || strcmp(namelist[i],"..")==0)
continue;
if(S_ISDIR(stalist[i].st_mode)){
strcpy(temp,path);
strcat(path,"/");
strcat(path,namelist[i]);
count=file_list(path,sta,name,mode);
display_RU(sta,name,count,mode);
strcpy(path,temp);
}
}
}
/*-Rl 參數，顯示所有檔案，包括目錄下面的子目錄的詳細資料*/
void display_RU_LL(struct stat * stalist,char (*namelist)[LENGTH],int n,int mode)
{
int i,count;
char path[LENGTH]={0},temp[LENGTH]={0};
struct stat sta[MAX_FILE_COUNT];
char name[MAX_FILE_COUNT][LENGTH];
puts(get_current_dir_name());
display_LL(stalist,namelist,n);
putchar('n');
strcpy(path,get_current_dir_name());

for(i=0;i<n;i++){
if(strcmp(namelist[i],".")==0 || strcmp(namelist[i],"..")==0)
continue;
if(S_ISDIR(stalist[i].st_mode)){
strcpy(temp,path);
strcat(path,"/");
strcat(path,namelist[i]);
count=file_list(path,sta,name,mode);
display_RU_LL(sta,name,count,mode);
strcpy(path,temp);
}
}
}
/*-Ri 參數，簡單顯示所有檔案，包括目錄下的子目錄，及節點號*/
void display_RU_IL(struct stat* stalist,char (*namelist)[LENGTH],int n,int mode)
{
int i,count;
char path[LENGTH]={0},temp[LENGTH]={0};
struct stat sta[MAX_FILE_COUNT];
char name[MAX_FILE_COUNT][LENGTH];
puts(get_current_dir_name());
display_IL(stalist,namelist,n);
putchar('n');
strcpy(path,get_current_dir_name());

for(i=0;i<n;i++){
if(strcmp(namelist[i],".")==0 || strcmp(namelist[i],"..")==0)
continue;
if(S_ISDIR(stalist[i].st_mode)){
strcpy(temp,path);
strcat(path,"/");
strcat(path,namelist[i]);
count=file_list(path,sta,name,mode);
display_RU_IL(sta,name,count,mode);
strcpy(path,temp);
}
}
}
/*-Ril 參數，顯示所有檔案，包括目錄下面的子目錄的詳細資料，及節點號*/
void display_RU_IL_LL(struct stat * stalist,char (*namelist)[LENGTH],int n,int mode)
{
int i,count;
char path[LENGTH]={0},temp[LENGTH]={0};
struct stat sta[MAX_FILE_COUNT];
char name[MAX_FILE_COUNT][LENGTH];
puts(get_current_dir_name());
display_LL_IL(stalist,namelist,n);
putchar('n');
strcpy(path,get_current_dir_name());

for(i=0;i<n;i++){
if(strcmp(namelist[i],".")==0 || strcmp(namelist[i],"..")==0)
continue;
if(S_ISDIR(stalist[i].st_mode)){
strcpy(temp,path);
strcat(path,"/");
strcat(path,namelist[i]);
count=file_list(path,sta,name,mode);
display_RU_IL_LL(sta,name,count,mode);
strcpy(path,temp);
}
}
}
//錯誤處理函數
void error(char* error_message,int line)
{
char str[5];
sprintf(str,"%d:",line);
strcat(str,error_message);
perror(str);
exit(EXIT_FAILURE);
}