Finding File Names
Regex | Purpose |
---|
"inputFile_[0-9]{3}\\.txt" | Match file names with the format: inputFile_NNN.txt e.g. inputFile_034.txt where N are digits. |
"inputFile_[0-9]{3}\\.txt" | Match file names with the format: inputFile_NNN.txt eg. inputFile_034.txt where N are digits. |
"inputFile_" + $fileSeq + "\\.txt" | Match file names with the format: inputFile_$fileSeq.txt e.g. inputFile_034.txt where $fileSeq="034" |
Regex Arguments in Expressions
Code Block |
---|
if(!matches(value,"[\\p{Alnum}\\p{Space}]+"),error('Please only enter alpha numeric characters') |
Checks whether any characters are not (!)
alphanumeric characters or spaces. If any are not, matches() will evaluate to 1, and the error message will be presented. The +
is a greedy quantifier, so it can match more than once. This means value
can contain as many alphanumeric characters or spaces as it likes, so long as it does not contain anything else.
Code Block |
---|
$xml = replaceAll($xml, "<sc_tower_torqueing/type><id.*?<name>", "<type>"),
$xml = replaceAll($xml, "</name></sc_tower_torqueing/type>", "</type>"), |
The first line matches text with the pattern:
-
sc_tower_torqueing/type><id.
- followed by
any character, indicated by the wildcard *
- however many times it appears, indicated by
?
- followed by the text
<name>
to finish.
Any matching pattern is changed to the text <type>
.
The second line matches the exact text </name></sc_tower_torqueing/type>
and changes any occurrence to “</type>". As the exact text is known, this does not require a regex.
In a regex, some characters, called meta-characters, have special meanings. For example quote marks “
mark the the start and end of a string; see Regular expression metacharacters for a full list and their functions. To use a meta-character as if it is a normal character, use an escape character so that the regex can ignore its special meaning.
Use | To escape | For example |
---|
2 backslashes | \\ | . () [] {}
* ^ + $ | ?
| \\.
\\]
\\^
|
3 backslashes | \\\ | a backslash \ quote marks " | \\\\ \\\" |
For example, the following regex shows some characters are escaped and some are not.
Code Block |
---|
replaceAll(JSON Code,"[^\\p{Space}0-9A-Za-z!:\\\"%&\\[*()\\],-/_\\\\{}\\.]","") |
This regex checks text to make sure it does not contain any unusual characters by defining a list of allowed characters:
- paragraph end marks:
\\p
- spaces:
{Space}
- numbers 0-9:
0-9
- uppercase or lowercase alphabetic characters:
A-Za-z
- other characters:
! : % & * ( ) , - / _ { }
- special characters, preceded by backslashes to escape them:
" [ ] \ .
Characters with special meaning are:
- quotes and square brackets:
“[
and ]"
indicate the start and the end of the string - caret
^
means NOT, so match anything that is NOT in the following list.
This regex ignores any of the allowed characters. If it finds any character not in the list, it replaces them with nothing, indicated by ""
.
Tip |
---|
A double backslash \\ can also make an alphanumeric character a construct. For example, \\n means newline; see Characters below. Escaping an alphabetic character that does not form construct causes an error. |
For information about escaping characters in PhixFlow expressions