1 use strict;
 2 use warnings;
 3 
 4 
 5 #将读入的内容添加到原字符串后面
 6 my $buffer=‘START:‘;
 7 my $byts = sysread(STDIN,$buffer, 10, length($buffer));
 8 #my $byts = read(STDIN,$buffer, 10, length($buffer));
 9 print $buffer,"\n";
10 
11 #将字符串添加到文件后面
12 open(FD, ">1.txt");
13 syswrite(FD,$buffer,10,2);
14 close(FD);
15  
#sysread无缓冲/read有缓冲
#print有缓冲/syswrite无缓冲
#systead可设置追加偏移量
#syswrite可设置写入长度与开始写入的位置