The dialog boxes of searching an replacng have such parameters:

- Pattern
- A string to find.
- Replace by
*(in the replace dialog box only)* - String, which will substitute the found pattern.
- Case sensitive
- Consider case of letters (if it is off, capital and small letters are equal).
- Whole word
- Search only those entries, which are whole words, but not part of a word (for example, if the patter is "or", then only conjunctions "or" will be found, but not all suffixes "or").
- Regular expressions
- Use regular expressions for searching.

In regular expressions, in addition to ordinary symbols, the following metasymbols can be used:

`^`- Beginning of line.
`$`- End of line.
`.`- Any symbol.
`\`- Interpret next symbol literally.
`*`- Zero or more times.
`+`- One or more times.
`{`*n*}- Exactly
*n*times. `{`*n*,}- Not less than
*n*times. `{`*n*,*m*}- From
*n*to*m*times. `[ ]`- Any simbol from the set (a range is indicated by symbol
`-`); for example,`[aeiou0-9]`matches any symbol of`a`,`e`,`i`,`o`,`u`, and digit from`0`to`9`; other operators and metasymbols don't work in the brackets. `[^ ]`- None of the set, for example,
`[aeiou0-9]`is none of the set`a`,`e`,`i`,`o`,`u`, and none of digits from`0`to`9`. `\w`- Any alpha-numeric symbol (including "
`_`"). `\W`- Any non-alphanumeric symbol.
`\d`- Digit.
`\B`- Non-digit.
`\s`- Space symbol (space or tab).
`\S`- Non-space symbol.
`\t`- Tab symbol.
`\n`- Line delimiter (for multi-lines patterns).
`|`- Previous or next pattern, for example,
`fee|fie|foe`means "`fee`" or "`fie`" or "`foe`". `( )`- The round brackets group a subexpression, which can be used for replace.

`$0`or`$&`- Whole found regular expression.
`$`*n**(n>0)*- Subexpression in round brackets number
*n*(from left to right beginning from one). If you need place a digit just after`$`, place*n**n*in braces:`${12}4`.