linux程序

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <fcntl.h>

#include <string.h>

#define ECHO_ORDER 8001

#define LIST_ORDER 8002

#define CD_ORDER 8003

#define PWD_ORDER 8004

#define EXIT_ORDER 8005

#define ERROR_ORDER -1

#define GOOD_ORDER 1

char command[1024];

char curpath[256];

char *margs[10] = {0};

char order[16];

void my_system(char *command)

{

memset(margs,0,sizeof(margs));

int kind;

strcpy(copy,command);

char *argp = NULL;

argp = strtok(" ",command);

strcpy(order,argp); //\u8bbe\u7f6e\u547d\u4ee4\u53c2\u6570

int argsnum = 0;

while(argp != NULL)

{

margs[argsnum] = (char)malloc(strlen(argp));

if(margs[argsnum] == NULL)

{

cout<<"malloc the room for margs failed"<<endl;

return;

}

argp = strtok(NULL," ");

argsnum++;

}

if(strcmp(order,"echo") == 0)

kind = ECHO_ORDER;

else if(strcmp(order,"ls") == 0)

kind = LIST_ORDER;

else if(strcmp(order,"cd") == 0)

kind = CH_ORDER;

else if(strcmp(order,"pwd") == 0)

kind = PWD_ORDER;

else if(strcmp(order,"exit") == 0)

kind = EXIT_ORDER;

else

kind = ERROR_ORDER;

execute(copy,kind,argsnum);

}

int execute (char *command,int kind,int argsnum)

{

switch(kind)

{

case ECHO_ORDER:

int index = 1;

while(index < argsnum)

{

printf("%s ",margs[index]);

}

printf("/n");

break;

case LIST_ORDER:

execvp("ls",margs);

break;

case CH_ORDER:

if(chdir(margs[2]) < 0)

{

printf("the input dirctory is wrong");

return ERROR_ORDER;

}

break;

case PWD_ORDER:

getcwd(curpath\uff0c256);

printf("%s\n",curpath);

break;

case EXIT_ORDER:

exit(0);

case ERROR_ORDER:

return ERROR_ORDER;

}

}

int main()

{

while(true)

{

cin>>command;

my_system(command);

}

return 0;

}