如何用PowerShell与Regex仅匹配running-config的首个line vty条目

Hey there! The issue with your current script is that it scans the entire config file—including both running and startup sections—so it picks up all 4 line VTY entries. To target just the first one from the running-config section, we can adjust the script to isolate that section first before searching.

Here's the modified PowerShell script that does exactly what you need:

# Read the entire config file as a single string (makes section splitting easier)
$configContent = Get-Content -Path c:\test\config.txt -Raw

# Extract only the running-config section (everything between "show running-config" and "start-up config")
$runningConfigSection = ($configContent -split 'start-up config')[0] -replace '^show running-config\s*', ''

# Find the first line vty entry along with its 6 lines of context, then keep only the first match
$firstRunningVTY = Select-String -InputObject $runningConfigSection -Pattern "\sline\svty\s\d{1}\s\d{1,2}" -Context 0,6 | Select-Object -First 1

# Output the result
Write-Host $firstRunningVTY

Let's break down what each part does: #

• Get-Content -Raw: Reads the entire file into one string instead of separate lines, which simplifies splitting the config into sections.
• Splitting the config: We split the content at the "start-up config" marker to grab everything before it (the running-config section), then remove the "show running-config" header using -replace.
• Select-Object -First 1: Ensures we only capture the first matching line VTY entry from the isolated running-config section.

Optional tweak: If your config might have multiple spaces between keywords (instead of single spaces), adjust the pattern to "\s*line\s+vty\s+\d+\s+\d+" to handle variable spacing.

内容的提问来源于stack exchange，提问作者CBLT