US5228133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method to perform text search in application programs in computer by selecting a character and scanning the text string to/from the selected character offset position
Assignee: Individual
•
Filing: 1990-10-01
•
Granted: 1993-07-13
•
Expires: 2010-10-01
Abstract
Abstract An improved method for text searching has application to application programs in computers, where the application program handles files written in a language. Advantageously a character within the first string is selected. In the general case the character selected is a relatively rarely used character in the language, and in simplified cases it is selected as non-alphabetic or as found within a set of characters known to be relatively rarely used. The file is then scanned, starting not at the beginning but rather from a position offset from the beginning of the file according to the position of the selected character within the first string. In the event of a match for that character, the remainder of the character positions of the first string are compared for a string-length match. The scanning terminates at a position short of the end of the file according to the position of the selected character within the first string, or terminates on a string-length match. The speed of a text search within a file is improved by an order of magnitude or more, and sometimes by two orders of magnitude.
Inventors
- 👤 Carl Oppedahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:10
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/90; G06F16/903; G06F16/90335; G06F16/90344; Y; Y10; Y10S; Y10S707/00; Y10S707/99931; Y10S707/99933; Y10S707/99936
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
181 words
In a computer having memory, and having a file within the memory, an improved text-search method for searching for a string within the file, said string having a length of f characters, f being a number greater than one, comprising the steps of: locating within the string a located character within the string that satisfied a predetermined condition, the location of said located character defining a first position p within the string; scanning within the file for an occurrence of a match between the located character and a character within the file in a range of positions no closer than p characters to the start of the file and no closer than 1+p-p characters to the end of the file, and terminating the text-search if no occurrence is found; inspecting the contents of the file from a position p-l characters preceding the occurrence to a position f-p characters following the occurrence for a match with the string, reporting a successful search at the position p-l characters preceding the occurrence in the event of a match, and otherwise repeating the scanning step.
Claim 2
Dependent Claim
181 words
In a computer having memory, and having a file within the memory, an improved text-search method for searching for a string within the file, said string having a length of f characters, f being a number greater than one, comprising the steps of: locating within the string a located character within the string that satisfied a predetermined condition, the location of said located character defining a first position p within the string; scanning within the file for an occurrence of a match between the located character and a character within the file in a range of positions no closer than p characters to the start of the file and no closer than 1+p-p characters to the end of the file, and terminating the text-search if no occurrence is found; inspecting the contents of the file from a position p-l characters preceding the occurrence to a position f-p characters following the occurrence for a match with the string, reporting a successful search at the position p-l characters preceding the occurrence in the event of a match, and otherwise repeating the scanning step.
Claim 3
Dependent Claim
31 words
The improved text-search method of claim 1 wherein the predetermined condition comprises a condition that the located character be non-alphabetic if there is at least one non-alphabetic character in the string.
Claim 4
Dependent Claim
46 words
The improved text-search method of claim 1 wherein the file and the string are text in a language and the predetermined condition comprises a condition that the located character located is less frequently used in the language than at least one other character in the string.
Claim 5
Dependent Claim
58 words
The improved text-search method of claim 1 wherein the file and the string are text in a language and the predetermined condition comprises a condition that the located character located is within a predetermined set of characters less frequently used in the language if there is at least one character from within the predetermined set in the string.
Claim 6
Dependent Claim
199 words
Text-search apparatus for finding a string of characters within a file of characters, the number of characters in the string being greater than 1 and the number of characters in the string defining an integer f, the apparatus comprising: a processor; a memory storing the file and the string; a parallel data bus operatively connecting the processor and the memory; means for locating within the string a located character within the string that satisfies a predetermined condition, the location of said location character defining a first position p within the string; means responsive to the located character for scanning within the file for an occurrence of a match between the located character and a character within the file in a range of positions no closer than p characters to the start of the file and no closer than 1+f-p characters to the end of the file; means responsive to the occurrence for inspecting the contents of the file from a position p-l characters preceeding the occurrence to a position f-p characters following the occurrence for a match with the string; and means responsive to the match for reporting a successful search at the position p-l characters preceding the occurrence.
Claim 7
Dependent Claim
199 words
Text-search apparatus for finding a string of characters within a file of characters, the number of characters in the string being greater than 1 and the number of characters in the string defining an integer f, the apparatus comprising: a processor; a memory storing the file and the string; a parallel data bus operatively connecting the processor and the memory; means for locating within the string a located character within the string that satisfies a predetermined condition, the location of said location character defining a first position p within the string; means responsive to the located character for scanning within the file for an occurrence of a match between the located character and a character within the file in a range of positions no closer than p characters to the start of the file and no closer than 1+f-p characters to the end of the file; means responsive to the occurrence for inspecting the contents of the file from a position p-l characters preceeding the occurrence to a position f-p characters following the occurrence for a match with the string; and means responsive to the match for reporting a successful search at the position p-l characters preceding the occurrence.
Claim 8
Dependent Claim
31 words
The improved text-search apparatus of claim 5 wherein the predetermined condition comprises a condition that the located character be non-alphabetic if there is at least one non-alphabetic character in the string.
Claim 9
Dependent Claim
45 words
The improved text-search apparatus of claim 5 wherein the file and the string text in a language and the predetermined condition comprises a condition that the located character located is less frequently used in the language than at least one other character in the string.
Claim 10
Dependent Claim
58 words
The improved text-search apparatus of claim 5 wherein the file and the string are text in a language and the predetermined condition comprises a condition that the located character located is within a predetermined set of characters less frequently used in the language if there is at least one character from within the predetermined set in the string.
References Cited (Backward Citations)
US4003025A
Cited
US4531201A
Cited
US4625295A
Cited
US4941124A
Cited
US5119327A
Cited
US4556951A
Cited
US4589142A
Cited
US4760523A
Cited
US4916655A
Cited
US5033098A
Cited
US5138669A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-12 | 1997-01-11 | 1997-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-12 | 2001-01-11 | 2001-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-12 | 2005-01-11 | 2005-07-13 | $7700.00 | Window Closed / Lapsed |