regex¶

• regex is an extremely powerful tool for editing text and automation
• you can fix a problem with regex
• try it: https://regex101.com/

between around¶

• find text with something before, in between or after

(?<=This is)(.*)(?=sentence)

• Groups & Lookaround

(abc) capture group
\1 backreference to group #1
(?:abc) non-capturing group
(?=abc) positive lookahead
(?!abc) negative lookahead

remove blank lines¶

^(\s)*$\n

timestamps¶

remove some timestamps from end of ticket summary

\ \d{1,}.*$

validation¶

email

"^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"

past or future tense¶

• docs should be in present tense

To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:

" [A-Z] "

This pattern matches any single uppercase letter.

To replace the matched patterns with their lower case equivalents, you can use the following replacement string:

" \l "

This replacement string uses the \l modifier to convert the matched character to lowercase.

Here is an example of how to use this regular expression in Python:

import re

string = "THIS IS AN UPPERCASE STRING."

# Replace any upper case with its lower case
new_string = re.sub(r'[A-Z]', r'\l', string)

# Print the new string
print(new_string)

Output:

this is an uppercase string.

This regular expression can be used in any programming language that supports regular expressions.

passive voice¶

• you should write doc in active voice

To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:

" [A-Z] "

This pattern matches any single uppercase letter.

To replace the matched patterns with their lower case equivalents, you can use the following replacement string:

" \l "

This replacement string uses the \l modifier to convert the matched character to lowercase.

Here is an example of how to use this regular expression in Python:

import re

string = "THIS IS AN UPPERCASE STRING."

# Replace any upper case with its lower case
new_string = re.sub(r'[A-Z]', r'\l', string)

# Print the new string
print(new_string)

Output:

this is an uppercase string.

This regular expression can be used in any programming language that supports regular expressions.

capitol to lower¶

To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:

" [A-Z] "

This pattern matches any single uppercase letter.

To replace the matched patterns with their lower case equivalents, you can use the following replacement string:

" \l "

This replacement string uses the \l modifier to convert the matched character to lowercase.

Here is an example of how to use this regular expression in Python:

import re

string = "THIS IS AN UPPERCASE STRING."

# Replace any upper case with its lower case
new_string = re.sub(r'[A-Z]', r'\l', string)

# Print the new string
print(new_string)

Output:

this is an uppercase string.

This regular expression can be used in any programming language that supports regular expressions.

title case¶

To write a regular expression that replaces any word using Title case with lower case title, you can use the following pattern:

\b[A-Z]\w+\b

This pattern matches any word that starts with an uppercase letter (\b[A-Z]) followed by one or more lowercase letters (\w+). \b is a word boundary, which ensures that the match is a complete word and not just part of a larger word.

To replace the matched patterns with lower case title, you can use the following replacement string:

\1\L$2

This replacement string uses the capture group \1 to capture the first letter of the matched word. It then uses the \L modifier to convert the first letter to lowercase. The $2 capture group is used to capture the rest of the matched word, which is then left unchanged.

Here is an example of how to use this regular expression in Python:

import re

string = "This Is A Title Case String."

# Replace any word using Title case with lower case title
new_string = re.sub(r'\b[A-Z]\w+\b', r'\1\L$2', string)

# Print the new string
print(new_string)

Output:

This is a title case string.

This regular expression can be used in any programming language that supports regular expressions.

trailing .¶

To write a regular expression that replaces trailing . symbols with nothing, you can use the following pattern:

\.+$

This pattern matches one or more periods (.) at the end of the string ($).

To replace the matched patterns with nothing, you can use the following replacement string:

""

This is an empty string, so it will effectively remove the trailing periods.

Here is an example of how to use this regular expression in Python:

import re

string = "This string has a trailing period."

# Replace the trailing . with nothing
new_string = re.sub(r'\.$', "", string)

# Print the new string
print(new_string)

Output:

This string has a trailing period

This regular expression can be used in any programming language that supports regular expressions.

old examples¶

old micro app¶

        $cleanoutput = $_.ToString() -replace 'System.Exception: ERROR: ', ""
        $cleanoutput = $cleanoutput.Split(",")
        $regname = [regex]"(?<=\[\\\\server\\path\\path\\\d{3}Matchme_)(.*?)(?=\\0)"
        $cleanname = $regname.Match($cleanoutput)
        write-host $cleanname
        $html += "<br>"
        $html += $cleanname
        $regtranid = [regex]"(?<=The)(.*?)(?=has)"
        $cleantran = $regtranid.Match($cleanoutput)
        write-host $cleantran

utilities¶

searching for useful logging

    $badlist | ForEach-Object {
        Write-Host
        $_ | select *
        $_.name -replace '\\\\server\\', ''`
            -replace 'c\$\\server\\Output\\', ''`
            -replace 'serverOutput\d{3}\\', ''`
            -replace '\\\d{3}_\d{14}\.out'
    } | Get-Unique -OutVariable $fixed