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Regular expressions describe patterns in strings that can be used in order to determine whether a given pattern occurs in a text or not. In UltraSearch, regular expressions can be used to find specific files and / or folders that match the criteria specified by regular expressions
The following table shows some of the most used syntax and provides a few examples:
Expression |
Syntax |
Description |
Example |
Any character |
. |
Matches any single character except a line break. |
a.o matches "aro" in "around" and "abo" in "about" but not "acro" in "across". |
Zero or more |
* |
Matches zero or more occurrences of the preceding expression, and makes all possible matches. |
a*b matches "b" in "bat" and "ab" in "about". e.*e matches the word "enterprise". |
One or more |
+ |
Matches at least one occurrence of the preceding expression. |
ac+ matches words that contain the letter "a" and at least one instance of "c", such as "race", and "ace". a.+s matches the word "access". |
Start of string |
^ |
Matches the start of a string |
^[0-9] matches strings that start with a digit. |
End of string |
$ |
Matches the end of a string |
exe$ matches strings that end with "exe". |
Beginning of word |
[[:<:]] |
Matches only when a word starts at this point in the text. |
[[:<:]]in matches words such as "inside" and "into" that begin with the letters "in". |
End of word |
[[:>:]] |
Matches only when a word ends at this point in the text. |
ss[[:>:]] matches words such as "across" and "loss" that end with the letters "ss". |
Any one character in the set |
[] |
Matches any one of the characters in the []. To specify a range of characters, list the starting and ending characters separated by a dash (-), as in [a-z]. |
be[n-t] matches "bet" in "between", "ben" in "beneath", and "bes" in "beside" but not "bel" in "below". |
Any one character not in the set |
[^...] |
Matches any character that is not in the set of characters that follows the ^. |
be[^n-t] matches "bef" in "before", "beh" in "behind", and "bel" in "below", but not "ben" in "beneath". |
Or |
| |
Matches either the expression before or the one after the OR symbol (|). Mostly used in a group. |
(sponge|mud) matches "sponge bath" and "mud bath. |
Escape character |
\ |
Matches the character that follows the backslash (\) as a literal. This lets you find the characters that are used in regular expression notation, such as { and ^. |
\^ searches for the ^ character. |
Repeat n times |
{n} |
Matches n occurrences of the preceding expression. |
[0-9]{4} matches any 4-digit sequence. |
Grouping |
() |
Lets you group a set of expressions together. If you want to search for two different expressions in a single search, you can use the Grouping expression to combine them. |
If you want to search for [a-z][1-3] or [0-9][a-z], you would combine them: ([a-z][1-3])|([0-9][a-z]). |
More examples:
Regular Expression |
Use Case |
[0-9] or \d |
Find all files/folders with at least one digit in its name. |
a|b |
Find all files/folders containing "a" or "b" in their name. |
[^(A-Za-z)] |
Find all files/folders containing at least one character in their name that is not in the range A-Z or a-z. |
^E[0-9]{7}$ |
Find all files/folders which start with an "E" followed by exactly 7 digits. |
[A-Za-z]:\\([^\\]+\\){2,4}[^\\]+$ |
Find all files/folders with a folder depth of at least 2 and at most 4. |
[^\x00-\x7F] |
Find all files/folders with invalid ASCII characters. |
[^\P{C}] |
Find all files/folders with Unicode characters which cannot be printed. |
[\xA0] |
Find all file/Folder names that contain the non-breakable space character (Unicode NOBR, U+00A0) instead of a normal space character. |
[~\"#%&\*\:<>\?\/\\{|}] |
Find all file and folder names, that contain characters which are invalid on SharePoint servers. |
^\s+.* |
Find all files and folders with a leading space. |
\s+(\.[^.]+)$ |
Find files with an extension that have a trailing space at the end of their name. |
.*\s+$ |
Find folders with a trailing space at the end of their name |
Further information and additional examples can be found here.
A description of all special characters that can be used with regular expression can be found here.
The following tools can assist in forming regular expressions:
https://regex101.com/ (online)
http://regexpal.com/ (online)
http://sourceforge.net/projects/regexpeditor/ (download)
http://sourceforge.net/projects/regextester/ (download)
http://sourceforge.net/projects/regaxe/ (download)