srt_tran.c

unix下进行电报传输的源码。采用信号灯技术避免文件冲突等等

#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include "nfcnet.h"
long file_size(void);
int  semset(void);
int  semopena(int semset_semid,int semset_semno);
int  semopenr(int semset_semid,int semset_semno);
int  semclose(int semset_semid,int semset_semno);
main()
{ int statusx; int semid; int i,ijk,in;
  FILE *fp1,*fp2;
  semid=semset();
  printf("Semid is %d\n",semid);
  ijk=0;
  for(;;)
  { if(file_size()==0L)
    { statusx=semopenr(semid,P_SR_TRAN);
      if(statusx==0)
      { if((fp1=fopen("/nfcnet/temp/sr_tran0.tmp","rb+"))==NULL)
        { fp1=fopen("/nfcnet/temp/sr_tran0.tmp","a+");
          fclose(fp1);
          fp1=fopen("/nfcnet/temp/sr_tran0.tmp","rb+");}
        fp2=fopen("/nfcnet/ddbf/sr_tran1.tmp","ab+");
        for(;;){in=fgetc(fp1); if(in==EOF)break; fputc(in,fp2);}
        fp1=freopen("/nfcnet/temp/sr_tran0.tmp","w+",fp1);
        fclose(fp1); fclose(fp2);
        statusx=semclose(semid,P_SR_TRAN);
      }
      if(statusx==-1) printf("SRT_TRAN semopenr is error !\n");
    }
    else
    { printf("/nfcnet/ddbf/sr_tran1.tmp is not empty !\n");}
    printf("SRT_TRAN Waiting for (%d) mins(%d) . \n",P_SLEEPTIME,ijk);
    ijk++; if(ijk==1000)ijk=0;
    sleep(P_SLEEPTIME*60);
  }
}
long file_size(void)
{ long f_size; FILE *fp;
  f_size=0L;
  if((fp=fopen("/nfcnet/ddbf/sr_tran1.tmp","r"))!=NULL)
  { fseek(fp,0L,SEEK_END);
    f_size=ftell(fp);
    fclose(fp);
  }
  return f_size;
}
int  semset(void)
{ int semset_semid;
  key_t semset_key=   P_SEMSKEY;
  int semset_nsems=   P_SEMNUMB;
  int semset_semflg=  IPC_CREAT|P_SEMACCESS;
  semset_semid=semget(semset_key,semset_nsems,semset_semflg);
  return semset_semid;
}
int  semopena(int semset_semid,int semset_semno)
{ extern int errno; int status; 
  int semset_semflg=P_SEMACCESS;
  struct sembuf *semset_sops;
  struct sembuf semset_sopsbuf;
  size_t semset_nsops=1;
  semset_sops=&semset_sopsbuf;
  semset_sopsbuf.sem_num=semset_semno;
  semset_sopsbuf.sem_op=-1;
  semset_sopsbuf.sem_flg=semset_semflg;
  status=semop(semset_semid,semset_sops,semset_nsops); 
  if(status==-1) {return -1;} else {return 0;}
}
int  semopenr(int semset_semid,int semset_semno)
{ extern int errno; int status;
  int semset_semflg=P_SEMACCESS|IPC_NOWAIT;
  struct sembuf *semset_sops;
  struct sembuf semset_sopsbuf;
  size_t semset_nsops=1;
  semset_sops=&semset_sopsbuf;
  semset_sopsbuf.sem_num=semset_semno;
  semset_sopsbuf.sem_op=-1;
  semset_sopsbuf.sem_flg=semset_semflg;
  status=semop(semset_semid,semset_sops,semset_nsops); 
  if(status==-1) {return -1;} else {return 0;}
}
int semclose(int semset_semid, int semset_semno)
{ extern int errno; int status;
  int semset_semflg=P_SEMACCESS|IPC_NOWAIT;
  struct sembuf *semset_sops;
  struct sembuf semset_sopsbuf;
  size_t semset_nsops=1;
  semset_sops=&semset_sopsbuf;
  semset_sopsbuf.sem_num=semset_semno;
  semset_sopsbuf.sem_op=1;
  semset_sopsbuf.sem_flg=semset_semflg;
  status=semop(semset_semid,semset_sops,semset_nsops); 
  if(status==-1) {return -1;} else {return 0;}
}