The fourth bird questions

The fourth bird answers

• How to update a multichracter delimited field in a file in bash?
• RegEx pattern to not allow special character except underscore
• How to skip, if starts with, but match other strings
• How to distinguish numbers from ip addresses in regular expressions?
• How to find all words with first letter as upper case using Python Regex
• Target URLs with special characters
• return text between two characters
• Move elements using array_chunk with PHP
• How to validate such input using a regular expression?
• Checking for whitespaces with RegEx