//fileopen.c
#include<stdio.h>
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
int main()
{
char temp[]="hello,abc!";
int fd;
char pathname[255];
if((fd=open("fileopen.txt",O_WRONLY|O_CREAT,0640))==-1)
{
printf("creat file wrong!");
}
int len=strlen(temp)+1;
write(fd,temp,len);//若fd为0，或这里直接写0，则会输出到屏幕上而不写入文件中
close(fd);
}
//fileopen2.c
#include<sys/types.h>
#include<sys/stat.h>
#include<unistd.h>
#include<fcntl.h>
#include <stdio.h>
int main()
{
int fa;
int s=12;
int len;
char text[20]="hello,fileopen2!!!";
fa=open("fileopen2.txt",O_WRONLY|O_CREAT,0640);
//len = sprintf(text, "%d", s);
write(fa,text,sizeof(text));
close(fa);
}
//test_system_fprintf_fopen.c
#include<stdio.h>
#include<stdlib.h>
int main()
{
FILE *stream;
char temp[255];
char *a="hello,c!";
stream=fopen("fprintf.txt","w");
fprintf(stream,"%s\n",a);
fprintf(stream,"sb,c++\n");
sprintf(temp,"nl fprintf.txt");
fclose(stream);
printf("%s\n",temp);
system(temp);//system函数参数可以为字符串指针或直接字符串
system("nl fprintf.txt");
exit(0);
return 0;
}
//file-rw.c
#include<stdio.h>
#include<fcntl.h>
#include<unistd.h>
int main()
{
int fdr,fdw;
char temp[255];
char filepath[255];
char fileto[255];
printf("please input the filepath:");
scanf("%s",filepath);
if((fdr=open(filepath,O_RDONLY))==-1)
{
printf("file not found,open failed!");
return -1;
}
else
{
int r_size=read(fdr,temp,255);
close(fdr);
sprintf(fileto,"file-rw.txt");
if((fdw=open(fileto,O_WRONLY|O_CREAT,0640))==-1)
{
printf("open failed!");
return -1;
}
else
{
int w_size=write(fdw,temp,r_size);//相当于复制了所输入文件.txt中的255个大小的字符串到新文件file-rw.txt中
close(fdw);
printf("have successfully copied 255 chars from \"%s\" to \"%s\"\n",filepath,fileto);
}
}
return 0;
}