Event editor protocol: Find
Find What. Definition of the string
of characters to be found.
Match Case. To differentiate upper case and lower case characters
in the string.
If this option is not selected, the search is carried out regardless the case of
characters.
Search.
Regular Expression. the characters string looked for is specified in the
form of an expression, or regular expression, made up using ordinary characters from the
ASCII set and from special characters called metacharacters.
If this option is not selected, only ordinary characters from the ASCII set are
recognized.
Find with regular-expression
The Find function finds all characters 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 characters string looked for is specified in the form of an expression, or regular
expression, made up using ordinary characters from the ASCII set 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 figures from 0 to 9.
- abbreviations for character series: two characters separated by a - define the series of
characters between these 2 limits (classed in the ASCII order).
The ( ) metacharacters are used in the regular expressions to define groups of
characters (to which, for example, 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 realizing the OR function.
- concatenation uses an implicit operator: AB confirms A immediately followed by B.
The regular expressions are continuous strings without SPACE 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 figure. |
| A|B |
|
A or B. |
| AB |
|
A immediately followed by B. |
| *A |
|
zero or several A's. |
| +A |
|
one or more A's. |
| ?A |
|
zero or an A. |
| (AB) |
|
the same strings as AB. |
Examples of regular expressions for the event search:
- 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.
| 