Regular Expressions 101

Community Patterns

22

Get path from any text

Created·2023-01-31 14:38
Updated·2023-07-23 20:17
Flavor·PCRE2 (PHP)
Recommended·
Get path (windows style) from any type of text (error message, e-mail corps ...), quoted or not. THIS IS THE SINGLE LINE VERSION ! If you want understand how it work or edit it, go https://regex101.com/r/7o2fyy Relative path are not supported The goal is to catch what "Look like" a path. See the limitations UNC path and prefix path like //./], [//?/] or [//./UNC/] are allowed some url path like [file:///C:/] or [file://] are allowed Catch path quoted with ["] and [']. But these quotes are include with the catch Quoted path is not concerned by limitations Limitations : (only unquoted path) [dot] and [space] is allowed, but not in a row [dot+space] or [space+dot at end of file name isn't catched INSIDE A NAME FILE (or last directory if it is a path to a directory) : [comma] is not supported (it stop the catch) after a first [dot], any [space] stop the catch after a [space], catch is stoped if next character is not a [letter], [digit] or [-] so, double [space] stop the catch Compatibility compatible PCRE, PCRE2 AutoHotkey : don't forget to escape "%" in "`%" /!\ Powershell and .Net /!\\ : this regex need some modification to be interpreted by powershell. You have to replace each (?&CapturGroupName) by \k. Use this powershell code to do this replacement : ` $powershellRegex = @' [Put here the regex to replace (?&CapturGroupName) with \k] '@ -replace '\(\?&(\w+)\)', '\k' ` This example code must return : [Put here the regex to replace \k with \k]
Submitted by nitrateag

Community Library Entry

0

Regular Expression
Created·2019-08-28 00:06
Flavor·Python

r"
^[ \t]*((?P<label>([a-zA-Z_][a-zA-Z0-9_]*))[ \t]*:)?[ \t]*((?P<opc>[a-zA-Z]+)[ \t]*([ \t](?P<op1>[a-zA-Z0-9_\.\"]+)([ \t]*\,[ \t]*(?P<op2>[a-zA-Z0-9_]+))?)?)?[ \t\n\f\r\v]*(;.*)?$
"
gm
Open regex in editor

Description

Returns 4 groups,

  • label = label used in the start, if any
  • opc = Opcode mnemonic if the line contains an instruction
  • op1 = first operand to mnemonic, if any
  • op2 = second operand to mnemonic, if any

If a value is absent, returns None. (Python does this)

Can be easily extended to 3 operand instructions by adding one more subgroup.

Line matching syntax

General syntax is -

LABEL:OPC OPERAND1,OPERAND2;Comment

where -
LABEL = (optional) 
OPC = (optional)
OPERAND1 = (optional, needs OPC)
OPERAND2 = (optional, needs both OPC and OPERAND1)
COMMENT = (optional)

Examples

  • this_is_a_label: MOV A, B ; Comments are also supported
  • ; Comments start with semicolon
  • empty_line_with_only_a_label:
  • MVI A, 01H ; No label in start
Submitted by anonymous