［转］Linux文件操作函数open close read write等示例

来源：互联网发布：eslyric源码编辑：程序博客网时间：2024/05/20 14:41

//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;}