無緩衝IO

#include /* Standard input/output definitions */

#include /* String function definitions */

#include /* UNIX standard function definitions */

#include /* File control definitions */

#include /* Error number definitions */

#include /* POSIX terminal control definitions */

#include

#define ENTER 10 /*ASCII code of LF in linux*/

#define MAX 10

int main(void) {

//int fd;

//fd = open("/dev/ttyS0", O_RDWR|O_NOCTTY|O_NDELAY);

int fp, fp2;

char str[MAX],ch;// buffer

int bytes=0;

fp=open("copyfile1.txt", O_RDWR);

fp2=open("output.txt", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);//

if( (fp==-1) || (fp2==-1) )

{

printf("file cannot be opened, fp=%d, fp2=%d\n", fp, fp2);

return 1;

} else {

while( (bytes=read(fp, str, MAX))>0){

write(fp2, str, bytes);//

}

}

close(fp2);//

close(fp);

printf("Copying finish...\n");

return 0;

}