Perl中的文件处理：从特定行读取文件 [英] File Handling in Perl: Reading a file from a specific line

问题描述

有没有办法在Perl中开始从一个特定的行号读取文件。每当我们在perl中读取一个文件时，我们都会执行（<$ fileHandler>），这使得perl解释器从头开始读取文件。如果我不想阅读这些文章，该怎么办？ 解决方案

$ start_line ，

  my $ start_line = 10; 
 while（< $ fileHandler>）{
 next除非$。 == $ start_line .. undef; 
 
 
 
 code 
 $ b 
  范围运算符..  还提供以下内容简写：
 $ b 
 
 
如果标量..的任何一个操作数是一个常量表达式，那么该操作数在相等时被认为是真的（<$ （ $。变量）。
  blockquote> 
 
 
因此，上面可以简化为： 
 
 
  while（< $ fileHandler>）{
 next除非10 .. undef; 
 
＃.. 
} 
  
 
Is there no way in perl to start reading a file from a specific line number. Whenever we read a file in perl we do while(<$fileHandler>) which makes the perl interpreter to read the file from beginning. What to do if I don't want to read these lines?
解决方案
You can skip lines from the beginning, and start processing with $start_line,
my $start_line = 10;
while(<$fileHandler>) {
  next unless $. == $start_line .. undef;

  # ..
}
The range operator .. also provides the following shorthand:

  
If either operand of scalar ".." is a constant expression, that operand is considered true if it is equal (==) to the current input line number (the $. variable).
Therefore the above can be reduced to:
while(<$fileHandler>) {
  next unless 10 .. undef;

  # ..
}


                        
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