情報システム科学3サポートページ(担当 田中哲朗)

4/26課題のプログラムリスト

#include <stdio.h>
extern int errno;
#include <fcntl.h>

main(int ac, char **ag){
  char buf[16*1024];
  int size;
  int ifd, ofd;
  if(ac!=3) exit(1);
  if((ifd=open(ag[1],O_RDONLY))<0){
    fprintf(stderr,"Failed opening file %s\n",ag[1]);
    fprintf(stderr,"errno=%d\n",errno);
    exit(1);
  }
  if((ofd=open(ag[2],O_WRONLY|O_CREAT,0666))<0){
    fprintf(stderr,"Failed creating file %s\n",ag[2]);
    fprintf(stderr,"errno=%d\n",errno);
    exit(1);
  }
  while((size=read(ifd,buf,sizeof(buf)))>0){
    write(ofd,buf,size);
  }
  close(ifd);
  close(ofd);
}

5/24課題のプログラムリスト

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

void setupFile(char *fileName){
  char buf[256];
  int i,fd;
  for(i=0;i<256;i++) buf[i]=i;
  if((fd=open(fileName,O_WRONLY|O_CREAT,0600))<0){
    fprintf(stderr,"Failed in opening file");
    exit(1);
  }
  if(write(fd,buf,256)<0){
    fprintf(stderr,"Failed in writing file");
    exit(1);
  }
  close(fd);
}

int main(int ac,char **ag){
  char *fileName="dummy";
  if(ac>1) fileName=ag[1];
  setupFile(fileName);
  return 0;
}

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

void readFile(char *fileName){
  char c;
  int i,fd;
  if((fd=open(fileName,O_RDONLY))<0){
    fprintf(stderr,"Failed in opening file");
    exit(1);
  }
  for(i=0;i<256;i++){
    int rsize;
    if((rsize=read(fd,&c,1))<0){
      fprintf(stderr,"Failed in reading file");
      exit(1);
    }
    else if(rsize==0){
      fprintf(stderr,"read size=0");
      break;
    }
    printf("%d: %d\n",i,c);
    sleep(1);
  }
  close(fd);
}

int main(int ac,char **ag){
  char *fileName="dummy";
  if(ac>1) fileName=ag[1];
  readFile(fileName);
  return 0;
}

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

void clearFile(char *fileName){
  char buf[256];
  int i,fd;
  for(i=0;i<256;i++) buf[i]=0;
  if((fd=open(fileName,O_WRONLY|O_CREAT,0600))<0){
    fprintf(stderr,"Failed in opening file");
    exit(1);
  }
  if(write(fd,buf,256)<0){
    fprintf(stderr,"Failed in writing file");
    exit(1);
  }
  close(fd);
}

int main(int ac,char **ag){
  char *fileName="dummy";
  if(ac>1) fileName=ag[1];
  clearFile(fileName);
  return 0;
}

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

void truncFile(char *fileName){
  char buf[256];
  int i,fd;
  for(i=0;i<256;i++) buf[i]=i;
  if((fd=open(fileName,O_WRONLY|O_TRUNC,0600))<0){
    fprintf(stderr,"Failed in opening file");
    exit(1);
  }
  close(fd);
}

int main(int ac,char **ag){
  char *fileName="dummy";
  if(ac>1) fileName=ag[1];
  truncFile(fileName);
  return 0;
}

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

void getcFile(char *fileName){
  int i;
  FILE *fp;
  if((fp=fopen(fileName,"r"))==NULL){
    fprintf(stderr,"Failed in opening file");
    exit(1);
  }
  for(i=0;i<256;i++){
    int c;
    if((c=getc(fp))==EOF){
      fprintf(stderr,"EOF\n");
      break;
    }
    printf("%d: %d\n",i,c);
    sleep(1);
  }
  fclose(fp);
}

int main(int ac,char **ag){
  char *fileName="dummy";
  if(ac>1) fileName=ag[1];
  getcFile(fileName);
  return 0;
}