如何在perl脚本中替换变量选项

发布时间：2020-12-15 23:35:39 所属栏目：大数据来源：网络整理

导读：在perl文本中,替换非常简单和强大. 我想做一个带有变量替换的脚本,例如： if ( $IgnoreCase ) {$opt = "gi"} else {$opt = "g"}$string =~ s/$source/$replace/$opt; 结果是： Scalar found where operator expected … 是否有可能做选项变量？解决方法因

在perl文本中,替换非常简单和强大.
我想做一个带有变量替换的脚本,例如：

if ( $IgnoreCase ) {$opt = "gi"} else {$opt = "g"}

$string =~ s/$source/$replace/$opt;

结果是：

Scalar found where operator expected …

是否有可能做选项变量？

解决方法

因为你在所有情况下都可以使用/ g,

my $opt = $IgnoreCase ? "(?i)" : "";

$string =~ s/$opt$source/$replace/g;

关于这个主题的更多内容在perldoc perlre

One or more embedded pattern-match modifiers,to be turned on (or turned off if preceded by “-” ) for the remainder of the pattern or the remainder of the enclosing pattern group (if any).

This is particularly useful for dynamically-generated patterns,such as those read in from a configuration file,taken from an argument,or specified in a table somewhere. Consider the case where some patterns want to be case-sensitive and some do not: The case-insensitive ones merely need to include (?i) at the front of the pattern.

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