笔记
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#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define MAX 100
int read_line(int fd, char *buf, int count)
{
int i;
char ch;
for(i = 0; i < count#include <stdio.h>
; i++)
{
if((read(fd,&ch,1)) < 0)
{
perror("read error!\n");
exit(1);
}
if(ch == '\n')
{
buf[i] = '\0';
return i;
}
buf[i] = ch;
}
buf[i - 1] = '\0';
return count;
}
int main()
{
int i;
int fd;
int w_count;
int r_count;
char filename[MAX];
char r_buf[MAX];
char w_buf[MAX];
printf("Please input filename:\n");
scanf("%s",filename);
if((fd = open(filename, O_CREAT | O_RDWR, 0755)) < 0)
{
perror("open error!\n");
exit(1);
}
for(i = 0; i < 3; i++)
{
memset(w_buf,0,sizeof(w_buf));
scanf("%s",w_buf);
if((w_count = write(fd,w_buf,strlen(w_buf))) < 0)
{
perror("write error!\n");
exit(1);
}
else
{
write(fd,"\n",1);
}
}
lseek(fd,0,SEEK_SET);
#if 0
if((r_count = read(fd,r_buf,sizeof(r_buf))) < 0)
{
perror("read error!\n");
exit(1);
}
else
{
r_buf[w_count * 3 + 3] = '\0';
printf("read data: %s\n",r_buf);
}
#endif
for(i = 0; i < 3; i++)
{
memset(r_buf,0,sizeof(r_buf));
read_line(fd,r_buf,100);
printf("read data: %s\n",r_buf);
}
close(fd);
return 0;
}
