shell.cpp

利用Linux系统函数实现的SHELL程式

#include <iostream>
#include <direct.h>
#include <string>

using namespace std;
    
#include "shell.h"
#include "commands.h"

char chr_PathName0[MAX_ENVIRONMENT_LENGTH]="";  //chr_PathName0 is original path name
char *chr_PathName=(char*)malloc(sizeof(char)*(MAX_ENVIRONMENT_LENGTH-100));  //Path name
char chr_Prompt0[MAX_ENVIRONMENT_LENGTH]="";  //chr_Promt0 is original Promt
char *chr_Prompt=(char*)malloc(sizeof(char)*MAX_ENVIRONMENT_LENGTH);  //Promt = Path name & shell name & promt character
char *chr_CommandLine=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);  //Command line including command and argument

int main(void){
	if(initial()){
		cout<<SHELL_NAME<<" started!"<<endl;
		
		do{
			reinitial(0,chr_PathName);
			cout<<chr_Prompt;
			cin.getline(chr_CommandLine,MAX_COMMANDLINE_LENGTH);  //Input command, length is limited by MAX_COMMANDLINE_LENGTH
			//Implement command
			cin.clear();
		}while(strcmp("quit",execute(chr_CommandLine)));
	}
	else cout<<"Initialization failed!"<<endl;
	return 0;
}

char *execute(char *tmpchr_CommandLine){
	//char *tokenPtr=strtok(tmpchr_CommandLine," ");
	char tmpchr0[MAX_COMMANDLINE_LENGTH]="";  //Used as a duplicate of char *tokenPtr
	char tmpchr1[MID_OUTPRINT]="";  //Used as a duplicate of output of fuctions:func_*
	char *tokenPtr;  //Used for getting the first part in the string:char *tmpchr_CommandLine
	strcpy(tmpchr0,tmpchr_CommandLine);
	tokenPtr=strtok(tmpchr0," ");

	if(tokenPtr==NULL)  //Command is null
		return "";
	
	else 
		if(strcmp(tokenPtr,"cd")==0) {cout<< func_cd(tmpchr_CommandLine);}
		else if(strcmp(tokenPtr,"clr")==0) {strcpy(tmpchr1,func_clr(getArgument(tmpchr_CommandLine)));}
		else if(strcmp(tokenPtr,"dir")==0) {strcpy(tmpchr1,func_dir(trim(tmpchr_CommandLine)));}
	    else if(strcmp(tokenPtr,"environ")==0) {strcpy(tmpchr1,func_environ(getArgument(tmpchr_CommandLine)));}
	    else if(strcmp(tokenPtr,"echo")==0) {strcpy(tmpchr1,func_echo(tmpchr_CommandLine));}
	    else if(strcmp(tokenPtr,"help")==0) {strcpy(tmpchr1,func_help(getArgument(tmpchr_CommandLine)));}
	    else if(strcmp(tokenPtr,"pause")==0) {strcpy(tmpchr1,func_pause(getArgument(tmpchr_CommandLine)));}
	    else if(strcmp(tokenPtr,"quit")==0) {strcpy(tmpchr1,func_quit(getArgument(tmpchr_CommandLine)));}
	    else strcpy(tmpchr1,func_else(tokenPtr));	
		
		cout<<tmpchr1;
	    if(strcmp(tmpchr1,func_quit(""))==0)
			return tokenPtr;		
		else
			return "";
}

char *strmid(char *sourceChr,int from,int length){  //'from' starts from 1
	//char *tmpchr0=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);
	//char *tmpchr0=(char*)malloc(sizeof(char)*strlen(sourceChr));
	char tmpchr0[MAX_COMMANDLINE_LENGTH]="";
	char *tmpchr1=(char*)malloc(sizeof(char)*strlen(sourceChr));
	int tmpint0=0;
	if((length+from-1)>(signed int)strlen(sourceChr)) return "";
	for(int tmpint1=from-1;tmpint1<=from+length-2;tmpint1++){
		tmpchr0[tmpint0]=sourceChr[tmpint1];
		tmpint0++;
	}
	strcpy(tmpchr1,tmpchr0);
	return tmpchr1;
}

char *getArgument(char *tmpchr_CommandLine){
	//char *tmpchr0=(char*)malloc(sizeof(char)*strlen(tmpchr_CommandLine));
	char *tokenPtr;
	char *tmpchr1=(char*)malloc(sizeof(char)*strlen(tmpchr_CommandLine));	
	char tmpchr0[MAX_COMMANDLINE_LENGTH];
	strcpy(tmpchr0,tmpchr_CommandLine);

	tokenPtr=strtok(tmpchr0," ");
	
	strcpy(tmpchr1,"");
	
	tokenPtr=strtok(NULL," ");
	while(tokenPtr!=NULL && strlen(tmpchr1)<=MAX_COMMANDLINE_LENGTH){
		strcat(tmpchr1,tokenPtr);
		tokenPtr=strtok(NULL," ");
		
		strcat(tmpchr1," ");
	}
	return tmpchr1;
}
	
bool initial(void){  //Used for the first time this shell start
 	getcwd(chr_PathName0,MAX_ENVIRONMENT_LENGTH);  //Stores the original path name
 	//getcwd(chr_PathName,MAX_ENVIRONMENT_LENGTH);
 	strcpy(chr_PathName,chr_PathName0);
	strcpy(chr_Prompt0,chr_PathName);  //Stores the original prompt
	strcpy(chr_Prompt,"<");
	strcat(chr_Prompt,chr_PathName);
	strcat(chr_Prompt,">/"); 
	strcat(chr_Prompt,SHELL_NAME);
	strcat(chr_Prompt,"$");
	return true;	
}
	
bool reinitial(int tmpint_Argument,char *tmpchr_Argument){  //Used for the relocate working directory
	//	getcwd(chr_PathName,MAX_ENVIRONMENT_LENGTH);	
	if(tmpint_Argument==0){
		chr_PathName=tmpchr_Argument;
	}
		
	strcpy(chr_Prompt,"<");		
	strcat(chr_Prompt,chr_PathName);
	strcat(chr_Prompt,">/"); 
	strcat(chr_Prompt,SHELL_NAME);
	strcat(chr_Prompt,"$");
	return true;
}

char *ltrim(char *tmpchr){
	char *ptrtmpchr; 
	ptrtmpchr=tmpchr;
	while(*ptrtmpchr==' '){
		*ptrtmpchr=*(ptrtmpchr+1);
		ptrtmpchr++;
	}
	return ptrtmpchr;
}

char *ltrim(char *tmpchr,char tmpchr_Tokenizer){
	char *ptrtmpchr; 
	ptrtmpchr=tmpchr;
	while(*ptrtmpchr==tmpchr_Tokenizer){
		*ptrtmpchr=*(ptrtmpchr+1);
		ptrtmpchr++;
	}
	return ptrtmpchr;
}

char *rtrim(char *tmpchr){
 	char *ptrtmpchr; 
	int inttmp0;
	ptrtmpchr=tmpchr;
	
	inttmp0=strlen(ptrtmpchr);
	while(*(ptrtmpchr+inttmp0-1)==' '){
		*(ptrtmpchr+inttmp0-1)='\0';
		inttmp0--;
	}
	return ptrtmpchr;
}
 
char *rtrim(char *tmpchr,char tmpchr_Tokenizer){
	char *ptrtmpchr; 
	int inttmp0;
	ptrtmpchr=tmpchr;
	inttmp0=strlen(ptrtmpchr);
	while(*(ptrtmpchr+inttmp0-1)==tmpchr_Tokenizer){
    
		*(ptrtmpchr+inttmp0-1)='\0';
		inttmp0--;
	}
	return ptrtmpchr;
}

char *trim(char *tmpchr){
	return rtrim(ltrim(tmpchr));
}

char *trim(char *tmpchr,char tmpchr_Tokenizer){
	return rtrim(ltrim(tmpchr,tmpchr_Tokenizer),tmpchr_Tokenizer);
}