在"9A“附近的-e第1行，”Bareword“找到了操作员所期望的位置

Question

为什么我会有语法错误？

% perl -ne 'if (/https://([-.0-9A-Za-z]+\.[-0-9A-Za-z]+)/) { print $1 ; }'
Bareword found where operator expected at -e line 1, near "9A"
        (Missing operator before A?)
Bareword found where operator expected at -e line 1, near "9A"
        (Missing operator before A?)
syntax error at -e line 1, near "9A"
syntax error at -e line 1, near ";}"
Execution of -e aborted due to compilation errors.

Answer 1

如果regex包含斜杠，请使用不同的字符和显式m运算符：

perl -ne 'if (m%https://([-.0-9A-Za-z]+\.[-0-9A-Za-z]+)%) { print $1 ; }'

或者：

perl -ne 'print $1 if m{https://([-.0-9A-Za-z]+\.[-0-9A-Za-z]+)}'