Xah Talk Show 2021-10-15 grep/sed find/replace in WolframLang elisp golang python perl PowerShell

• demo find replace in elisp Emacs: Xah Find Replace (xah-find.el)
• demo in powershell
• Golang: Script to Find Replace Multi-Pairs of Regex in a Directory
• Python: Script to Find Replace Multi-Pairs Regex in a Directory
• Perl: Find Replace String Pairs in Directory

• the main show. Writing a find/replace script in WolframLang

the main things you need to do for writing a find replace script.

1. walk a dir, recursively
2. open file, get content of the file
3. do find and replace of a given big string
4. how to write to a file

PowerShell. find replace all html files in a dir, recursive:

Get-ChildItem "c:/Users/xah/" -Recurse -Include *html | ForEach-Object { (Get-Content $_) -replace "elephant", "tiger" | Out-File $_.fullname }

shorter version using alias:

dir "c:/Users/xah/" -Recurse -Include *html | % { (gc $_) -replace "elephant", "tiger" | Out-File $_.fullname }

WolframLang. find replace all html files in a dir, recursive:

WriteString[#, StringReplace[ReadString@#, "elephant"->"tiger"]]& /@ FileNames["*html","c:/Users/xah/"]

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