perl 学习日记1（文件操作）

打开文件

if (open(TXT,"C:/Documents and Settings/Administrator/桌面/integrate.txt")) {

    print "successed!";

}

else {

      print "failed.";

      exit 1;

}

 

关闭文件句柄

close(TXT); # TXT是句柄名

 

用$!返回操作系统的相应出错消息

if (!open(TXT,"C:/Documents and Settings/Administrator/桌面/integrat.txt")){

    warn "cannot read integtate: $!";

} else {

    print " OK!";

    exit 1;

}

$!为“No such file or directory”

 

读取文件

open(TXT,"C:/Documents and Settings/Administrator/桌面/integrate.txt") or die "cannot open integrate: $!";

$line = ;

print $line;

输出为文件的第一行

 

打印整个文件

open(TXT,"C:/Documents and Settings/Administrator/桌面/integrate.txt") or die "cannot open integrate: $!";

while (defined($a = )){

       print $a;

}

或者使用$_

while (){

        print $_;

}

w h i l e循环将负责把输入行赋予$_

或者使用

@contents=; #文件的每一行作为数组的一个元素

print @contents;  #打印整个文件

print $contents[1]; #打印文件的第二行

 

写入文件

open(TXT,">>C:/Documents and Settings/Administrator/桌面/test.txt") or die "cannot open integrate: $!";

if (! print TXT "This entry was written at ",scalar(localtime),"\n"){          

    warn "Unable to write the test file: $!";          # print完成追加写入

}else {

 print "Operation successde!";

}

close(TXT);

open(TXT,"C:/Documents and Settings/Administrator/桌面/test.txt") or die "cannot open integrate: $!";

@new=;

print @new;

close(TXT);

 

拷贝文件

open(T1,">>C:/Documents and Settings/Administrator/桌面/test.txt") or die "cannot open integrate: $!";

open(T2,"C:/Documents and Settings/Administrator/桌面/test2.txt") or die "cannot open integrate: $!";

@contents=;

$a=2011;

print T1 "@contents $a";  # test将被追加写入test2的内容和2011.

close(T1);

close(T2);

或者print T1 ; #效果相同，更为简洁