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by Michael-John Turner
Import upstream version 2.04 |
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This is version 2.04 of agrep - a new tool for fast |
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text searching allowing errors. |
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agrep is similar to egrep (or grep or fgrep), but it is much more general |
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(and usually faster). |
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The main changes from version 1.1 are 1) incorporating Boyer-Moore |
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type filtering to speed up search considerably, 2) allowing multi patterns |
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via the -f option; this is similar to fgrep, but from our experience |
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agrep is much faster, 3) searching for "best match" without having to |
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specify the number of errors allowed, and 4) ascii is no longer required. |
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Several more options were added. |
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To compile, simply run make in the agrep directory after untar'ing |
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the tar file (tar -xf agrep-2.04.tar will do it). |
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The three most significant features of agrep that are not supported by |
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the grep family are |
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1) the ability to search for approximate patterns; |
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for example, "agrep -2 homogenos foo" will find homogeneous as well |
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as any other word that can be obtained from homogenos with at most |
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2 substitutions, insertions, or deletions. |
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"agrep -B homogenos foo" will generate a message of the form |
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best match has 2 errors, there are 5 matches, output them? (y/n) |
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2) agrep is record oriented rather than just line oriented; a record |
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is by default a line, but it can be user defined; |
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for example, "agrep -d '^From ' 'pizza' mbox" |
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outputs all mail messages that contain the keyword "pizza". |
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Another example: "agrep -d '$$' pattern foo" will output all |
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paragraphs (separated by an empty line) that contain pattern. |
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3) multiple patterns with AND (or OR) logic queries. |
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For example, "agrep -d '^From ' 'burger,pizza' mbox" |
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outputs all mail messages containing at least one of the |
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two keywords (, stands for OR). |
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"agrep -d '^From ' 'good;pizza' mbox" outputs all mail messages |
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containing both keywords. |
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Putting these options together one can ask queries like |
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agrep -d '$$' -2 '<CACM>;TheAuthor;Curriculum;<198[5-9]>' bib |
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which outputs all paragraphs referencing articles in CACM between |
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1985 and 1989 by TheAuthor dealing with curriculum. |
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Two errors are allowed, but they cannot be in either CACM or the year |
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(the <> brackets forbid errors in the pattern between them). |
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Other features include searching for regular expressions (with or |
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without errors), unlimited wild cards, limiting the errors to only |
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insertions or only substitutions or any combination, |
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allowing each deletion, for example, to be counted as, say, |
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2 substitutions or 3 insertions, restricting parts of the query |
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to be exact and parts to be approximate, and many more. |
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agrep is available by anonymous ftp from cs.arizona.edu (IP 192.12.69.5) |
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as agrep/agrep-2.04.tar.Z (or in uncompressed form as agrep/agrep-2.04.tar). |
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The tar file contains the source code (in C), man pages (agrep.1), |
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and two additional files, agrep.algorithms and agrep.chronicle, |
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giving more information. |
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The agrep directory also includes two postscript files: |
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agrep.ps.1 is a technical report from June 1991 |
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describing the design and implementation of agrep; |
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agrep.ps.2 is a copy of the paper as appeared in the 1992 |
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Winter USENIX conference. |
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Please mail bug reports (or any other comments) |
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to sw@cs.arizona.edu or to udi@cs.arizona.edu. |
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We would appreciate if users notify us (at the address above) |
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of any extensions, improvements, or interesting uses of this software. |
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January 17, 1992 |
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BUGS_fixed/option_update |
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1. remove multiple definitions of some global variables. |
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2. fix a bug in -G option. |
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3. fix a bug in -w option. |
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January 23, 1992 |
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4. fix a bug in pipeline input. |
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5. make the definition of word-delimiter consistant. |
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March 16, 1992 |
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6. add option '-y' which, if specified with -B option, will always |
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output the best-matches without a prompt. |
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April 10, 1992 |
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7. fix a bug regarding exit status. |
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April 15, 1992 |