commands.cpp

利用Linux系统函数实现的SHELL程式

#include <string>
#include <iostream>
#include <stdlib.h>
#include <dirent.h>
#include <unistd.h>

using namespace std;

#include "shell.h"
#include "commands.h"

extern char chr_Prompt0[MAX_ENVIRONMENT_LENGTH];  //chr_Promt0 is original Promt
extern char chr_PathName0[MAX_ENVIRONMENT_LENGTH];  //Original path name
extern char *chr_PathName;  //Path name
char *chr_SysemReturn=(char*)malloc(sizeof(char)*MID_OUTPRINT);  //Used to get information returned by system()

char *func_cd(char *chrtmp_Argument){  //This argument has not been processed by 'char* getArgument(char*)'
	//char *advan_chrtmp_Argument is an advanced argument for chrtmp_Argument
	char *advan_chrtmp_Argument=(char*)malloc(sizeof(char)*(strlen(chrtmp_Argument)+strlen(chr_PathName)));	
	//char *tmpchr0 stores the whole command line that will run in system()
	char *tmpchr0=(char*)malloc(sizeof(char)*(strlen(chrtmp_Argument)+strlen(chr_PathName)));
	//char *tmpchr1 sotres the relative directory
	char *tmpchr1; 
	//char *tmpchr2 stores the absolute directory
	char *tmpchr2=(char*)malloc(sizeof(char)*(strlen(chrtmp_Argument)+strlen(chr_PathName)));
	//char *tmpchr3 is used as a temporary variable for chr_PathName
	char *tmpchr3=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);
	strcpy(advan_chrtmp_Argument,trim(chrtmp_Argument));	
	tmpchr1=trim(strmid(advan_chrtmp_Argument,4,strlen(advan_chrtmp_Argument)-3));
	strcpy(tmpchr2,chr_PathName);
	strcat(tmpchr2,"/");	
	strcat(tmpchr2,tmpchr1);

	if(!strcmp(strmid(trim(tmpchr1),1,1),"")){
		//"cd"
		//system("cd");
		initial();  //chr_PathName=chr_PathName0;
	}
	else if(!strcmp(strmid(tmpchr1,1,1),".") && (!strcmp(strmid(tmpchr1,2,1),"") || !strcmp(strmid(tmpchr1,2,1)," "))){
		system("cd .");
	}
	else if(!strcmp(strmid(tmpchr1,1,2),"..") && (!strcmp(strmid(tmpchr1,3,1),"") || !strcmp(strmid(tmpchr1,3,1)," "))){
		internal_func_cd1();
		cout<<"cd .."<<endl;		
	}
	else if(!strcmp(strmid(tmpchr1,1,1),"/") && (!strcmp(strmid(tmpchr1,2,1),"") || !strcmp(strmid(tmpchr1,2,1)," "))){
		strcpy(tmpchr0,"cd \"");
		strcat(tmpchr0,tmpchr1);
		strcat(tmpchr0,"\"");
		cout<<tmpchr0<<endl;
		if(system(tmpchr0)==0){  //Runs well
			strcpy(chr_PathName,"/");
		}
	}
	else if(!strcmp(strmid(trim(tmpchr1),1,1),"/")){
		strcpy(tmpchr0,"cd \"");
		strcat(tmpchr0,tmpchr1);
		strcat(tmpchr0,"\"");
		if(system(tmpchr0)==0){  //Runs well
			strcpy(chr_PathName,trim(tmpchr1,'/'));
			}
	}		
	else 
	{  //Directory is a sub-directory at current working directory
		strcpy(tmpchr0,"cd \"");
		strcat(tmpchr0,tmpchr2);
		strcat(tmpchr0,"\"");
		if(system(tmpchr0)==0){  //Runs well
			strcat(chr_PathName,"/");			
			strcat(chr_PathName,trim(tmpchr1,'/'));
		}
	}
	
	cout<<"chr_PathName: "<<chr_PathName<<endl;
	strcpy(tmpchr3,"/");
	strcpy(chr_PathName,trim(chr_PathName,'/'));
	strcat(tmpchr3,chr_PathName);
	strcpy(chr_PathName,tmpchr3);
	chdir(chr_PathName);
	return "";
}
	
char *func_clr(char *chrtmp_Argument){
	char* returnInfo0=argumentIsNull("clr",chrtmp_Argument);
	char *returnInfo1="";
	if(strlen(returnInfo0)<2){
		system("cls || clear"); 
		return returnInfo1;
	}
	else
		return returnInfo0;
}
	
char *func_dir(char *chrtmp_Argument){
	char* tmpchr0=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);
	char* tmpchr1;
	char* returnInfo0;
	
	chdir(chr_PathName);  //Synchronize current working directory
	
	strcpy(tmpchr0,"dir ");
	tmpchr1=strmid(chrtmp_Argument,5,strlen(chrtmp_Argument)-4);
	returnInfo0=argumentIsNull("quit",tmpchr1);
	
	if(strlen(returnInfo0)<2){
		strcat(tmpchr0,"\"");
		strcat(tmpchr0,chr_PathName);
		strcat(tmpchr0,"\"");
		system(tmpchr0);
	} 
	else
	{
		strcat(tmpchr0,tmpchr1);
		system(tmpchr0);
	}
	
	return "";
}

char *func_environ(char *chrtmp_Argument){
	char* returnInfo0=argumentIsNull("environ",chrtmp_Argument);
	char* returnInfo1=(char*)malloc(sizeof(char)*MAX_ENVIRONMENT_LENGTH);

	if(strlen(returnInfo0)<2){	
		strcpy(returnInfo1,SHELL_NAME);	
		strcat(returnInfo1,"_Path = ");	
		strcat(returnInfo1,chr_Prompt0);	
		strcat(returnInfo1,"\n");
		return returnInfo1;
	}
	else
		return returnInfo0;
}

char *func_echo(char *chrtmp_Argument){
	char* tmpchr0=(char*)malloc(sizeof(char)*strlen(chrtmp_Argument));
	char* tmpchr1;
	tmpchr1=ltrim(chrtmp_Argument);

	//char tmpchr0[MAX_COMMANDLINE_LENGTH];
	if(strlen(chrtmp_Argument)>=6){
		strcpy(tmpchr0,strmid(tmpchr1,6,strlen(tmpchr1)-5));
		strcat(tmpchr0,"\n");
		return tmpchr0;
	}
	else
		return "\n";
}

char *func_help(char *chrtmp_Argument){
	char* returnInfo0=argumentIsNull("help",chrtmp_Argument);
	char* returnInfo1="help information...\n";

	return (strlen(returnInfo0)<2 ? returnInfo1 : returnInfo0);
}

char *func_pause(char *chrtmp_Argument){
	char* returnInfo0=argumentIsNull("pause",chrtmp_Argument);
	char* returnInfo1="";
	if(strlen(returnInfo0)<2){
		char *tmpchr0=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);
		cin.getline(tmpchr0,MAX_COMMANDLINE_LENGTH);	
		cin.clear();
	}
	else
		return returnInfo0;
	return returnInfo1;
}

char *func_else(char* chrtmp_CommandLine){
	char *tmpchr0=(char*)malloc(sizeof(char)*MAX_COMMANDLINE_LENGTH);

	strcpy(tmpchr0,"No such command: '");
	strcat(tmpchr0,chrtmp_CommandLine);
	strcat(tmpchr0,"' in ");
	strcat(tmpchr0,SHELL_NAME);
	strcat(tmpchr0," !\nLoaded commands in system shell instead.\n");
	system(chrtmp_CommandLine);
	return tmpchr0;
}
	
char *func_quit(char *chrtmp_Argument)
{   	
	char *returnInfo0=argumentIsNull("quit",chrtmp_Argument);
	char *returnInfo1=(char*)malloc(sizeof(char)*256);
	if(strlen(returnInfo0)<2){
		strcpy(returnInfo1,SHELL_NAME);
		strcat(returnInfo1," exited!\n");	
		chdir(chr_PathName0);  //Return to the original directory
		return returnInfo1;
	}
	else
		return returnInfo0;
}

char *argumentIsNull(char *chrtmp_Command, char *chrtmp_Argument){  //if str(chrtmp_Argument)>1,it returns an error report
	char *tmpchr0=(char*)malloc(sizeof(char)*256);
	if(strcmp(chrtmp_Argument,"")==0)
		return " ";
	else
	{
		strcpy(tmpchr0,"Command '");
		strcat(tmpchr0,chrtmp_Command);
		strcat(tmpchr0,"' doesn't support arguments!\n");
		return tmpchr0;
	}
}

void internal_func_cd1(void){
	//Used as a temporary variable for chr_PathName
	char *tmpchr_PathName=(char*)malloc(sizeof(char)*strlen(chr_PathName));
	//Stores characters separated by strtok(tmpchr_PathName,"/")
	char *tmpchrArray[strlen(chr_PathName)];
	char *tokenPtr;
	int inti1;  //Used in while() below
	
	//Initialize char *tmpchrArray[]
	for(int inti0=0;inti0<=(signed int)strlen(chr_PathName);inti0++){
		tmpchrArray[inti0]=(char*)malloc(sizeof(char)*strlen(chr_PathName));
	}
	
	//Separate tmpchr_PathName by "/"
	inti1=0;
	strcpy(tmpchr_PathName,chr_PathName);
	tokenPtr=strtok(tmpchr_PathName,"/");
	while(tokenPtr!=NULL){
		strcpy(tmpchrArray[inti1],tokenPtr);
		inti1++;
		tokenPtr=strtok(NULL,"/");
	}

	strcpy(chr_PathName,"");
	
	for(int inti2=0;inti2<inti1-1;inti2++){
		strcat(chr_PathName,"/");
		strcat(chr_PathName,tmpchrArray[inti2]);
	}
}