Event Editor Protocol: Find
Find What: Definition of the string of characters
to be found.
Match Case: To differentiate between upper case
and lower case characters when searching.
If this option is not selected, search strings will be matched irrespective
of character case.
Search:-
Regular Expression: The search string is specified in
the form of an expression, or regular expression, composed of ordinary
ASCII characters and from special metacharacters.
If this option is not selected, only ordinary characters from the ASCII
set are recognised.
Find with regular-expression
The Find function finds all character combinations which can
be displayed on the screen. Each event is therefore accessible via its
representation, its type, a field value, whatever language is chosen. The function uses the pattern matching rules from the AWK language available
under UNIX and MKS for character-comparison rules:-
- One group of characters, the metacharacters, has
a special significance: \ ^ $ . [ ] | () * + ?.
- The search string is specified in the form of an expression, or regular
expression, composed of ordinary ASCII characters and from metacharacters.
- The ordinary characters are those from the basic ASCII sets completed
by those of the Windows set from 128 to 255 (input by ALT0xxx in which
xxx represents the 3 digits of the location in the Windows table).
- A certain number of characters which cannot be displayed or those
corresponding to the metacharacters are designated in the regular expression
by the escape sequences.
| Metacharacters |
|
|
| \ |
|
Quoting character |
| ^ |
|
A line beginning |
| $ |
|
The end of line |
| . |
|
Any individual character |
| [] |
|
A class of characters |
| ( ) |
|
Group operator |
| | |
|
Alternative operator |
| * |
|
Closing operator |
| + |
|
Positive closing operator |
| ? |
|
Zero or one operator |
| Escape Sequence |
|
|
| \b |
|
Backspace |
| \f |
|
Formfeed |
| \n |
|
New line |
| \r |
|
Carriage return |
| \t |
|
Tab |
| \meta |
|
Meta designates one of the metacharacters
(\ ^ $ .....) |
The metacharacters [ ] define a class of characters:-
- Any of the characters in a sequence inside the class confirms the
condition.
- ^ defines an additional class of characters; [^0-9] designates all
the different characters for numbers from 0 to 9.
- Abbreviations for character series: two characters separated by a
- define the series of characters between these two
limits (classed in the ASCII order).
The ( ) metacharacters are used in the regular expressions
to define groups of characters (e.g. to which operators are applied).
Definition of operators:-
- * is the repetition operator designating any repetition
number (0 or n times).
- + is the repetition operator designating any repetition
number (from 1 to n times).
- ? is the repetition operator designating a repetition number,
0 or 1 time.
- | is the alternative operator realising the OR function.
- Concatenation uses an implicit operator: AB confirms
A immediately followed by B.
The regular expressions are continuous strings without any spaces except
to designate the space character itself.
The regular expressions can be combined together by using the operators and
parentheses. The order of priority for operators is:-
* + ?, Concatenation, |.
| Regular expression |
|
Designation |
| \* |
|
The * literal character. |
| ^ABC |
|
ABC at beginning of line. |
| ABC$ |
|
ABC at end of line. |
| [ABC] |
|
Any A, B, or C character. |
| [A-Za-z] |
|
Any letter. |
| [^0-9] |
|
Any character EXCEPT a numeral. |
| A|B |
|
A or B. |
| AB |
|
A immediately followed by B. |
| *A |
|
Zero or several As. |
| +A |
|
One or more As. |
| ?A |
|
Zero or an A. |
| (AB) |
|
The same strings as AB. |
Examples of regular expressions for the event searching:-
- SABM points to the first SABM or SABME frame.
- RNR|REJ points to the first RNR or REJ frame.
- ^18:3[6-8] points to the events between 18h36 and
18h38.
| 
