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Linux下ls命令的实现

发布时间:2015-01-03 15:33:44来源:linux网站作者:sina012345

实现Linux下的ls命令,网上的代码总是不是太完善。主要实现ls,ls -l两个功能。分栏排序不是很满意,linux原版分栏简直赞,对齐的十分完美。这个代码是在网上的基础上改bug和修改完成。代码更新在:https://github.com/ljfly/ls


主要函数void do_ls( int,char [] );
void dostat( char * ); /*get file info*/
void show_file_info( char *,struct stat * ); //ls -l 的输出
void display_Ls( int cnt ) // ls 的分栏输出
void mode_to_letters( int,char [] ); //文件属性: drwxr-xr-x
char *uid_to_name( uid_t ); /* 通过 uid 获得对应的用户名 */
char *gid_to_name( gid_t ); /* 通过 gid 获得对应的组名 */
void getcolor( char * ); //获取压缩颜色
int get_file_type( char * ); /*get file type*/
int get_modify_time( char * ); /*get file last modify time*/
void getWidth(); //获取屏幕宽度

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<sys/ioctl.h>
#include<dirent.h>
#include<pwd.h>
#include<grp.h>
#include<unistd.h>

/*head file*/

#define LenOfName 256
#define maxN 1005
#define maxM 505
#define maxL 105
#define LenOfPath 256<<4
#define LS 0  //ls
#define LS_A 1//ls -a
#define LS_L 2//ls -l
#define LS_TMP 3  //ls /tmp
#define LS_T 5//ls -t
/*define file*/

void do_ls( int,char [] );
void dostat( char * );  /*get file info*/
void show_file_info( char *,struct stat * );  //ls -l 的输出
void mode_to_letters( int,char [] );//文件属性:drwxr-xr-x
char *uid_to_name( uid_t );  /* 通过uid获得对应的用户名 */
char *gid_to_name( gid_t );  /* 通过gid获得对应的组名 */
void getcolor( char * );  
int get_file_type( char * );/*get file type*/
int get_modify_time( char * );/*get file last modify time*/
void getWidth();
int cmp1( const void * ,const void * );  //文件名排序
int cmp2( const void * ,const void * );  //文件修改时间排序

struct outputFile{
char FileName[ LenOfName ];
int modify_time ;
int file_type ;
}Output[ maxN ],OutputPoint[ maxM ],Temp[ maxN+maxM ];
int colormode,foreground,background;
int terminalWidth ;

void dostat( char *filename ){
struct stat info;
if( stat( filename,&info )==-1 ){
perror( filename );
printf("filename:%s\n", filename);
}
else{
char *pname = strrchr(filename, '/');
getcolor(filename );
show_file_info( pname+1,&info );
}
return ;
}
/*get file info*/

void mode_to_letters( int mode,char str[] ){
strcpy( str,"----------" );
  
if( S_ISDIR( mode ) ) str[0] = 'd';
if( S_ISCHR( mode ) ) str[0] = 'c';
if( S_ISBLK( mode ) ) str[0] = 'b';
  
if( mode&S_IRUSR ) str[1] = 'r';
if( mode&S_IWUSR ) str[2] = 'w';
if( mode&S_IXUSR ) str[3] = 'x';
  
if( mode&S_IRGRP ) str[4] = 'r';
if( mode&S_IWGRP ) str[5] = 'w';
if( mode&S_IXGRP ) str[6] = 'x';
  
if( mode&S_IROTH ) str[7] = 'r';
if( mode&S_IWOTH ) str[8] = 'w';
if( mode&S_IXOTH ) str[9] = 'x';
  
return ;
}

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;
}
}

/* 通过uid获得对应的用户名 */

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;
}
}
/* 通过gid获得对应的组名 */

int get_file_type( char *filename ){
struct stat info;
stat( filename,&info );
int file_type = 0;
file_type = info.st_mode & S_IFMT;
return file_type;
}
/*get file type*/


int get_modify_time( char *filename ){
struct stat info;
stat( filename,&info );
int modify_time = 0;
modify_time = info.st_mtime;
return modify_time;
}
/*get file last modify time*/

int isadir(char *str)
{
struct stat info;
return ( lstat(str,&info) != -1 && S_ISDIR(info.st_mode) );
}
/*判断某文件是否为目录文件*/

void getWidth(){
char *tp;
struct winsize wbuf;
terminalWidth = 80;
if( isatty(STDOUT_FILENO) ){
if(ioctl(STDOUT_FILENO, TIOCGWINSZ, &wbuf) == -1 || wbuf.ws_col == 0){
if( tp = getenv("COLUMNS") )
terminalWidth = atoi( tp );
}
else
terminalWidth = wbuf.ws_col;
}
return ;
}
/******************************************************************
得出终端的宽度,默认宽度为80,如果获取失败,将激活-1选项
*******************************************************************/
int cmp1( const void *p ,const void *q ){
char T1[ LenOfName ],T2[ LenOfName ];
strcpy( T1,(*(struct outputFile *)p).FileName );
strcpy( T2,(*(struct outputFile *)q).FileName );
int len1 = strlen( T1 );
int i ;
for( i=0;i<len1;i++ ){
if( T1[ i ]>='A' && T1[ i ]<='Z' ){
T1[ i ] = T1[ i ] - 'A' + 'a';
}
}
int len2 = strlen( T2 );
for( i=0;i<len2;i++ ){
if( T2[ i ]>='A' && T2[ i ]<='Z' ){
T2[ i ] = T2[ i ] - 'A' + 'a';
}
}
return strcmp( T1,T2 );
}
/********************************************************
文件名排序  cmp1
*********************************************************/

int cmp2( const void *p,const void *q ){
return (*(struct outputFile *)p).modify_time < (*(struct outputFile *)q).modify_time ;
}
/********************************************************
文件修改时间排序  cmp2
*********************************************************/

void show_file_info( char *filename,struct stat * info_p ){
char modestr[ 12 ];
  
mode_to_letters( info_p->st_mode,modestr );
  
printf("%s",modestr);
printf("%3d ",(int)info_p->st_nlink);
printf("%-2s ",uid_to_name(info_p->st_uid));
printf("%-1s ",gid_to_name(info_p->st_gid));
printf("%7ld ",(long)info_p->st_size);
printf("%.12s ",4+ctime(&info_p->st_mtime));
printf("\033[%d;%d;%dm%s\033[0m\n",colormode,foreground,background,filename);
return ;
}
/*******************************************************
ls -l 的输出
********************************************************/
void getcolor( char *filename ){
struct stat info;
stat( filename,&info );
foreground = 30;
background = 1;
colormode = 0;
switch ( (info.st_mode & S_IFMT) ){
case S_IFREG:  /*regular 普通文件 , 色*/
foreground = 30;
colormode = 1;
break;
case S_IFLNK:  /*symbolic link 链接文件 , 青蓝色*/
foreground = 36;
colormode = 1;
break;
case S_IFSOCK:  /*紫红色*/
foreground = 35;
colormode = 1;
break;
case S_IFDIR:  /*directory 目录文件 , 蓝色*/
foreground = 34;
break;
case S_IFBLK:  /*block special 块设备文件 , 黄色*/
foreground = 33;
colormode = 1;
break;
case S_IFCHR:  /*character special 字符设备文件 , 黄色*/
foreground = 33;
colormode = 1;
break;
case S_IFIFO:  /*fifo  绿色*/
foreground = 32;
colormode = 1;
break;
}
}
/*******************************************************
给文件添加颜色
********************************************************/
void display_Ls( int cnt ){
int wordLenMax = 0;//the LenMax word
int wordRowNum = 0;//the amount of one row
int wordColNum = 0;//the amount of one col
int i , j;
for( i=0;i<cnt;i++ ){
if( i==0 ) wordLenMax = strlen( Output[ i ].FileName );
else wordLenMax = wordLenMax>strlen( Output[ i ].FileName )?wordLenMax:strlen( Output[ i ].FileName );
}
wordLenMax +=2;
wordRowNum = terminalWidth / wordLenMax;
if( cnt%wordRowNum==0 ) wordColNum = cnt / wordRowNum;
else wordColNum = cnt / wordRowNum + 1;
for( i=0;i<wordColNum;i++ ){
j = i;
while( j<cnt ){
getcolor( Output[ j ].FileName );
printf("\033[%d;%d;%dm%-15s\033[0m ",colormode,foreground,background,Output[ j ].FileName);
j += wordColNum;
}
printf("\n");
}
return ;
}  
/**********************************************************
ls的分栏输出
***********************************************************/

void display_Ls_a( int cntPoint,int cnt ){
int CNT = 0;
int wordLenMax = 0;//the LenMax word
int wordRowNum = 0;//the amount of one row
int wordColNum = 0;//the amount of one col
int i , j;
for( i=0;i<cntPoint;i++ ){
strcpy( Temp[ CNT ].FileName,OutputPoint[ i ].FileName );
Temp[ CNT ].file_type = OutputPoint[ i ].file_type;
Temp[ CNT ].modify_time = OutputPoint[ i ].modify_time;
CNT ++;
wordLenMax = wordLenMax>strlen( OutputPoint[ i ].FileName )?wordLenMax:strlen( OutputPoint[ i ].FileName );
}
for( i=0;i<cnt;i++ ){
strcpy( Temp[ CNT ].FileName,Output[ i ].FileName );
Temp[ CNT ].file_type = Output[ i ].file_type;
Temp[ CNT ].modify_time = Output[ i ].modify_time;
CNT ++;
wordLenMax = wordLenMax>strlen( Output[ i ].FileName )?wordLenMax:strlen( Output[ i ].FileName );
}
wordLenMax += 2;
wordRowNum = terminalWidth / wordLenMax;
if( CNT%wordRowNum==0 ) wordColNum = CNT / wordRowNum;
else wordColNum = CNT / wordRowNum + 1;
for( i=0;i<wordColNum;i++ ){
j = i;
while( j<CNT ){
getcolor( Temp[ j ].FileName );
printf("\033[%d;%d;%dm%-15s\033[0m ",colormode,foreground,background,Temp[ j ].FileName);
j += wordColNum;
}
printf("\n");
}
return ;
}
/**********************************************************
ls -a 的分栏输出
***********************************************************/
void display_Ls_tmp( int cnt ){
display_Ls( cnt );
return ;
}
/**********************************************************
ls /tmp 的分栏输出
***********************************************************/
void do_ls( int myJudge,char myOrder[] ){

char dirname[ maxL ];
if( myJudge!=LS_TMP  && myJudge!=LS_L){
strcpy( dirname,"." );
}
else {
strcpy( dirname,myOrder );
}
DIR * dir_ptr;
struct dirent *direntp;
int cntOutput = 0;
int cntOutputPoint = 0;
char full_path[256];
if( ( dir_ptr = opendir( dirname ) )==NULL ){
fprintf( stderr,"my god, i cannot open %s\n",dirname );
}
else{
if(myJudge!=LS_L ) {
while( (direntp = readdir( dir_ptr ) )!=NULL ){
if( direntp->d_name[ 0 ]=='.' ) {
strcpy( OutputPoint[ cntOutputPoint ].FileName,direntp->d_name );
OutputPoint[ cntOutputPoint ].file_type = get_file_type( OutputPoint[ cntOutputPoint ].FileName );
OutputPoint[ cntOutputPoint ].modify_time = get_modify_time( OutputPoint[ cntOutputPoint ].FileName );
cntOutputPoint ++;
}
else {
strcpy( Output[ cntOutput ].FileName,direntp->d_name );
Output[ cntOutput ].file_type = get_file_type( Output[ cntOutput ].FileName );
Output[ cntOutput ].modify_time = get_modify_time( Output[ cntOutput ].FileName );
cntOutput ++;
}
}
}
if( myJudge==LS_T ){
qsort( OutputPoint,cntOutputPoint,sizeof( OutputPoint[0] ),cmp2 );
qsort( Output,cntOutput,sizeof( Output[0] ),cmp2 );
}
else {
qsort( OutputPoint,cntOutputPoint,sizeof( OutputPoint[0] ),cmp1 );
qsort( Output,cntOutput,sizeof( Output[0] ),cmp1 );
}
/**********************************************************
预处理输出
***********************************************************/
if( myJudge==LS||myJudge==LS_T ){
display_Ls( cntOutput );
closedir( dir_ptr );
}
/**********************************************************
ls  && ls -t
***********************************************************/
else if( myJudge==LS_A ){
display_Ls_a( cntOutputPoint,cntOutput );
closedir( dir_ptr );
}
/**********************************************************
ls -a
***********************************************************/
else if( myJudge==LS_L ){
while( (direntp = readdir( dir_ptr ) )!=NULL ){
if( direntp->d_name[ 0 ]=='.' ) {
strcpy( OutputPoint[ cntOutputPoint ].FileName,direntp->d_name );
OutputPoint[ cntOutputPoint ].file_type = get_file_type( OutputPoint[ cntOutputPoint ].FileName );
OutputPoint[ cntOutputPoint ].modify_time = get_modify_time( OutputPoint[ cntOutputPoint ].FileName );
cntOutputPoint ++;
}
else {
strcpy(full_path, dirname);
int dir_len = strlen(dirname);
strcpy(full_path + dir_len, direntp->d_name);
strcpy( Output[ cntOutput ].FileName,full_path );
Output[ cntOutput ].file_type = get_file_type( Output[ cntOutput ].FileName );
Output[ cntOutput ].modify_time = get_modify_time( Output[ cntOutput ].FileName );

cntOutput ++;
}
}
int i;
for( i=0;i<cntOutput;i++ )
dostat( Output[ i ].FileName );
closedir( dir_ptr );
}
/**********************************************************
ls -l
***********************************************************/
else {
display_Ls_tmp( cntOutput );
closedir( dir_ptr );
}
/**********************************************************
ls /tmp
***********************************************************/
}
return ;
}/*sovle*/

int main( int argc, char *argv[] ){
getWidth( );
int i ;
if( argc==1 ){
do_ls( LS,"ls" );
}
else{
int ord;
while( (ord = getopt(argc,argv,":lat"))!=-1 ){
switch( ord ){
case 'a':
do_ls( LS_A,"ls-a" );
break;
case 'l':{
if(argc == 2)  do_ls( LS_L,"/" );
else  {
for( i= 2;i<argc;i++ ){
if( argv[ i ][ 0 ]=='-' ) continue;
printf("%s:\n",argv[ i ]);
do_ls( LS_L,argv[ i ] );
}
}
return;
}
break;
case 't':
do_ls( LS_T,"ls-t" );
break;
default :
break;
}
}
for( i=1;i<argc;i++ ){
if( argv[ i ][ 0 ]=='-' ) continue;
printf("%s:\n",argv[ i ]);
do_ls( LS_TMP,argv[ i ] );
}
}
return 0;
}
/*main*/