在 PowerShell 中,正则表达式(Regex)是一个强大的文本处理工具。本文将介绍一些实用的正则表达式技巧,帮助您更有效地处理文本数据。
首先,让我们看看基本的正则表达式匹配:
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| $text = "我的邮箱是 example@domain.com,电话是 123-456-7890" $emailPattern = "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}" $phonePattern = "\d{3}-\d{3}-\d{4}"
$email = [regex]::Match($text, $emailPattern).Value Write-Host "邮箱地址:$email"
$phone = [regex]::Match($text, $phonePattern).Value Write-Host "电话号码:$phone"
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使用正则表达式进行文本替换:
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| $logContent = @" 用户登录信息: 用户名:admin 密码:123456 IP地址:192.168.1.100 "@
$maskedContent = $logContent -replace "密码:.*", "密码:******" $maskedContent = $maskedContent -replace "\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}", "***.***.***.***"
Write-Host "`n处理后的日志内容:" Write-Host $maskedContent
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使用正则表达式验证数据格式:
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| function Test-DataFormat { param( [string]$InputString, [string]$Pattern ) if ($InputString -match $Pattern) { return $true } return $false }
$namePattern = "^[\u4e00-\u9fa5]{2,4}$" $testNames = @("张三", "李四", "王小明", "赵", "John")
foreach ($name in $testNames) { $isValid = Test-DataFormat -InputString $name -Pattern $namePattern Write-Host "姓名 '$name' 是否有效:$isValid" }
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使用正则表达式提取结构化数据:
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| $logEntry = "2024-03-27 10:30:45 [ERROR] 用户登录失败 - IP: 192.168.1.100, 用户名: admin" $logPattern = "(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}) \[(\w+)\] (.+) - IP: (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}), 用户名: (\w+)"
$matches = [regex]::Match($logEntry, $logPattern) if ($matches.Success) { $timestamp = $matches.Groups[1].Value $level = $matches.Groups[2].Value $message = $matches.Groups[3].Value $ip = $matches.Groups[4].Value $username = $matches.Groups[5].Value Write-Host "`n解析结果:" Write-Host "时间:$timestamp" Write-Host "级别:$level" Write-Host "消息:$message" Write-Host "IP:$ip" Write-Host "用户名:$username" }
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一些实用的正则表达式技巧:
使用命名捕获组:
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| $pattern = "(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})" $date = "2024-03-27" $matches = [regex]::Match($date, $pattern) Write-Host "年份:$($matches.Groups['year'].Value)"
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使用正向预查和负向预查:
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| $pricePattern = "\d+(?=元)" $text = "商品价格:100元,运费:20元" $prices = [regex]::Matches($text, $pricePattern) | ForEach-Object { $_.Value } Write-Host "`n价格:$($prices -join ', ')"
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使用正则表达式进行文本清理:
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| $dirtyText = "Hello World! This has extra spaces." $cleanText = $dirtyText -replace "\s+", " " Write-Host "清理后的文本:$cleanText"
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这些技巧将帮助您更有效地处理文本数据。记住,正则表达式虽然强大,但也要注意性能影响,特别是在处理大量数据时。对于简单的字符串操作,使用基本的字符串方法可能更高效。