/* ECP: FILEname=fig13_24.c */
/* 1*/   #include <stdio.h>
/* 2*/   #include <string.h>
/* 3*/   #include <sys/types.h>
/* 4*/   #include <sys/stat.h>
/* 5*/   #include <fcntl.h>
/* 6*/   #include <sys/wait.h>
/* 7*/   #include <unistd.h>
/* 8*/   #include <errno.h>
/* 9*/   #include <signal.h>

/*10*/   /* Simple Shell */

/*11*/   /* A Simple Command Is An Array Of Up To MaxArgc+1 Strings */
/*12*/   /* The Last String Is NULL */
/*13*/   /* This Can Be Used Directly For execvp */
/*14*/   /* Very Limited Error Checking To Keep Code Short */

/*15*/   #define MaxArgc 10
/*16*/   #define MaxPipes 10
/*17*/   #define FileNameLen MaxLineLen
/*18*/   #define MaxLineLen 256

/*19*/   typedef char *SimpleCommand[ MaxArgc + 1  ];

/*20*/   typedef struct
/*21*/   {
/*22*/       char InFile[ FileNameLen ];
/*23*/       char OutFile[ FileNameLen ];
/*24*/       int NumPipes;
/*25*/       SimpleCommand Commands[ MaxPipes ];
/*26*/       int Background;
/*27*/   } FullCommand;

/*28*/   enum { Eoln, Error, From, To, Pipe, Word, Amper };

/*29*/   /* Read A Line, return NULL On EOF */
/*30*/   #define GetLine( S ) ( fgets( S, MaxLineLen, stdin ) )

/*31*/   /* Return Pointer Indicating Where To Begin Next Search */
/*32*/   /* Str Will Be Filled if *Token Is Word, From, Or To */
/*33*/   char *GetToken( char *TheLine, char *Str, int *Token );