Mercurial > repos > bgruening > text_processing
diff grep.xml @ 7:d64eace4f9f3 draft
Uploaded
author | bgruening |
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date | Sat, 17 Jan 2015 08:30:15 -0500 |
parents | 8928e6d1e7ba |
children | fa7f88da29d7 |
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--- a/grep.xml Thu Jan 08 09:07:31 2015 -0500 +++ b/grep.xml Sat Jan 17 08:30:15 2015 -0500 @@ -124,12 +124,12 @@ - **^chr([0-9A-Za-z])+** would match lines that begin with chromsomes, such as lines in a BED format file. - **(ACGT){1,5}** would match at least 1 "ACGT" and at most 5 "ACGT" consecutively. - **hsa|mmu** would match lines containing "hsa" or "mmu" (or both). - + ----- **Regular Expression Syntax** -The select tool searches the data for lines containing or not containing a match to the given pattern. A Regular Expression is a pattern descibing a certain amount of text. +The select tool searches the data for lines containing or not containing a match to the given pattern. A Regular Expression is a pattern descibing a certain amount of text. - **( ) { } [ ] . * ? + \ ^ $** are all special characters. **\\** can be used to "escape" a special character, allowing that special character to be searched for. - **^** matches the beginning of a string(but not an internal line). @@ -145,8 +145,8 @@ - **{** n or n, or n,m **}** specifies an expected number of repetitions of the preceding pattern. - **{n}** The preceding item is matched exactly n times. - - **{n,}** The preceding item ismatched n or more times. - - **{n,m}** The preceding item is matched at least n times but not more than m times. + - **{n,}** The preceding item ismatched n or more times. + - **{n,m}** The preceding item is matched at least n times but not more than m times. - **[** ... **]** creates a character class. Within the brackets, single characters can be placed. A dash (-) may be used to indicate a range such as **a-z**. - **.** Matches any single character except a newline. @@ -154,10 +154,10 @@ - **?** The preceding item is optional and matched at most once. - **+** The preceding item will be matched one or more times. - **^** has two meaning: - - matches the beginning of a line or string. + - matches the beginning of a line or string. - indicates negation in a character class. For example, [^...] matches every character except the ones inside brackets. - **$** matches the end of a line or string. -- **\|** Separates alternate possibilities. +- **\|** Separates alternate possibilities. @REFERENCES@ ]]>