types.h

Linux下写一个命令解释程序,实现了基本的功能.

/* This file define the common structers which used in job control */

#if! defined (__TYPES_H_)
#define __TYPES_H_

#include <glob.h>
#include <sys/types.h>

enum redirection_type {
  REDIRECT_READ, REDIRECT_OVERWRITE, 
  REDIRECT_APPEND, REDIRECT_READWRITE
};

/* Structure describing a redirection. */
struct redirection_specifier
{
  enum redirection_type type;
  int fd;              /* File descriptor */
  char *filename;      /* File name */
};

/* Each child of the shell is remembered in a STRUCT PROCESS. */
typedef struct process {
  pid_t pid;		/* Process ID. */
  int is_stopped;	/* Non-zero if this process is running. */
  char **argv;     	/* The particular program that is running. */
  int num_redirections;
  struct redirection_specifier *redirections;
  glob_t glob_result;
  int free_glob;
} PROCESS;


typedef struct job {
  int id;             /* Job ID. */
  int num_progs;      /* Number of the programs in this job. */
  int running_progs;  /* Number of the programs still running in this job. */
  pid_t pgrp;         /* The process ID of the process group (necessary). */
  PROCESS *progs;     /* The pipeline of processes that make up this job. */
  struct job *next;
  int stopped_progs;
  char *text;
  char *cmd_buf;
} JOB;

/* Chain of the jobs */
typedef struct job_set {
  JOB *head;      /* The head of the chain. */
  JOB *fg;        /* The job which currently running in foreground. */
} CHAIN;

extern CHAIN job_list;

#endif /* __TYPES_H_ */