---json
{
    "description": "With this howto, you will learn what a  glob pattern is and how to use it to select data resources.",
    "low_quality_page": "false",
    "page_id": "s4oqxbqrrgnxp1jvy2kfu",
    "title": "How to select data resources with a Glob Pattern"
}
---
====== Tabulify - How to select data resources with a Glob Pattern  ======

===== About =====
With this page, you will learn what a <icon name="carbon:character-patterns"/> [[docs:common:globbing|glob pattern]] is and how to use it to select [[docs:resource:resource|data resources]].


A ''glob pattern'' or ''glob expression'' is a string that can be matched or not against another string. If the ''glob pattern'' matches, a [[docs:resource:resource|data resource]] name, the [[docs:resource:resource|data resource]] is selected otherwise it's not.

To express the pattern, special characters called ''wildcard'' are used that have special meaning. The following paragraphs go through each of this ''wildcard'' and shows you how to use them.

<note>
For the hackers, this is like a regular expression but simplified
</note>




===== Steps =====
==== Prerequisites ====
You should have ''Tabulify'' installed on your computer.

<btn>
[[howto:getting_started:1_install]]
</btn>


==== Star ====
The star character ''*'' also known as ''asterix'' matches any number of characters.

If we want to select all [[docs:resource:resource|data resources]] that ends with the term ''sales'', we will use the following ''glob pattern''
<code>
*sales
</code>
where:
  * ''*'' matches all characters before ''sales''
  * ''sales'' matches itself.

Example:
<unit>
<code dos>
tabli data list *sales@tpcds
</code>
<console>
PATH            
-------------   
catalog_sales   
store_sales     
web_sales
</console>
</unit>

==== Question mark ====
A question mark, ''?'', matches exactly one character.

Example:
  * ''????'' - Matches all data resources with exactly four letters or digits
<unit>
<code dos>
tabli data list ????@tpcds
</code>
<console>
PATH   
----   
item
</console>
</unit>
  * ''w?*sales'' - Matches any string beginning with ''w'', followed by at least one letter or digit, and ending with ''sales''
<unit>
<code dos>
tabli data list w?*sales@tpcds
</code>
<console>
PATH        
---------   
web_sales
</console>
</unit>

==== Braces ====

''Braces {}'' specify a collection of subpatterns. 

For example:

  * ''{item,store}'' matches ''item'' or ''store''
<unit>
<code dos>
tabli data list {item,store}@tpcds
</code>
<console>
PATH    
-----   
item    
store
</console>
</unit>
  * ''{web*,store*}'' matches all [[docs:resource:resource|data resource]] names that begins with ''web'' or ''store''.
<unit>
<code dos>
tabli data list {web*,store*}@tpcds
</code>
<console>
PATH            
-------------   
store           
store_returns   
store_sales     
web_page        
web_returns     
web_sales       
web_site
</console>
</unit>

==== Square brackets ====

''Square brackets []'' convey:
  * a set of single characters 
  * or a range of characters when the hyphen character (-) is used
that matches a single character.
Within the square brackets, the wildcard ''*'', ''?'', and ''\'' match themselves.

Example:
  * ''[aeiou]'' matches any lowercase vowel.
  * ''[0-9]'' matches any digit.
  * ''[A-Z]'' matches any uppercase letter.
  * ''[a-z,A-Z]'' matches any uppercase or lowercase letter.
  * ''[!abc]'' exclusion does not match the set of characters ''abc''
  * ''*[0-9]*'' ? Matches all strings containing a numeric value

Example:
  * all data resource that  does not have a ''wy'' in their name
<unit>
<code dos>
tabli data list *[wy]*@tpcds
</code>
<console>
PATH                   
--------------------   
inventory              
s_inventory            
s_warehouse            
s_web_order            
s_web_order_lineitem   
s_web_page             
s_web_returns          
s_web_site             
warehouse              
web_page               
web_returns            
web_sales              
web_site
</console>
</unit>

==== Double Star (Recursive Search) ====

You can also search [[docs:resource:container|container]] such as [[docs:resource:directory|directory]] or [[docs:resource:schema|schema]] recursively by adding to your glob pattern the double start (or asterix).

For instance, the below patter will search the file that starts with ''RE'' in the current directory and all sub-directories of the [[docs:connection:howto|howto connection directory]]
<unit>
<code dos>
tabli data list **/RE*@howto
</code>
  * And there is two ''README.md'' files found that match the pattern
<console>
PATH                  
-------------------   
README.md             
recursive\README.md
</console>
</unit>

==== Escape ====
The escape character is the backslash  ''\'' and turns a ''wildcard'' into a simple characters.

Syntax
<code>
\wildcard
</code>

For example:
  * ''\\'' will match a single backslash ''\''
  * ''\?'' matches the question mark ''?''
  * ''\*'' matches the star ''*''

<note>
This is almost always not needed because most of the wildcard are already not allowed when naming resource such as [[docs:resource:file|file]] or [[docs:resource:table|table]].
</note>