perl here document不起作用

使用perl here ducoment时<<之后的标识符和最后的标识符必须一致，包括空格。例如，

C:\Documents and Settings\Administrator>perl
$var = << HERE_TARGET; --多了一个空格，perl并不认为是"HERE_TARGET"
    your text
    goes here
HERE_TARGET
$var =~ s/^\s+//gm;
print $var;
^D  --此时没有任何输出,perl认为还没有结束
^C

C:\Documents and Settings\Administrator>perl
($var = <    your text
    goes here
HERE_TARGET
print $var;
^D
your text
goes here

 

如果一定要使用空格，可以将HERE_TARGET包含在引号(单引号或双引号)中。例如，

C:\Documents and Settings\Administrator>perl
($var = <<" HERE_TARGET") =~ s/^\s+//gm;
    your text
    goes here
 HERE_TARGET
print $var;
^D
your text
goes here