Linux C编程连载【1】-cp的实现

/********************************************************** * This program is use to copy src_file to dest_file * 1 Execute gcc -o copy copy.c * 2 then, copy the execute file "copy" to the /usr/bin * You can use command like this : copy src_file dest_file * Author : Tan De * Time : 2011-04-04 *********************************************************/ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/stat.h> #include <sys/types.h> #include <fcntl.h> #define BUFF_SIZE 1024 int main(int argc, char *argv[]){ int src_file,dest_file; int real_read_len; unsigned char buff[BUFF_SIZE]; //argc is not correct if(argc!=3){ printf("Error use copy!\n"); printf("Example:\n"); printf("copy src_file dest_file\n"); exit(1); } //Open src_file read only src_file=open(argv[1],O_RDONLY); //If the dest_file is not exsit, then create new one dest_file=open(argv[2],O_WRONLY|O_CREAT,666); //Open error if(src_file<0||dest_file<0){ printf("Open file error\n"); printf("Can't copy!\n"); printf("Please check cmd : copy src_file dest_file\n"); exit(1); } //Copy src_file to dest_file while((real_read_len=read(src_file,buff,sizeof(buff)))>0){ write(dest_file,buff,real_read_len); } //close fd close(dest_file); close(src_file); return 0; }