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comparison awk.xml @ 7:d64eace4f9f3 draft

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Uploaded
author bgruening
date Sat, 17 Jan 2015 08:30:15 -0500
parents 8928e6d1e7ba
children 062ed2bb4f2e
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6:8928e6d1e7ba 7:d64eace4f9f3
49 49
50 This tool runs the unix **awk** command on the selected data file. 50 This tool runs the unix **awk** command on the selected data file.
51 51
52 .. class:: infomark 52 .. class:: infomark
53 53
54 **TIP:** 54 **TIP:**
55 55
56 This tool uses the **extended regular** expression syntax (not the perl syntax). 56 This tool uses the **extended regular** expression syntax (not the perl syntax).
57 **\\d**, **\\w**, **\\s** etc. are **not** supported. 57 **\\d**, **\\w**, **\\s** etc. are **not** supported.
58 58
59 59
60 **Further reading** 60 **Further reading**
61 61
94 - If no action part is specified (not even the curly brackets) - the default action is to print the entire line. 94 - If no action part is specified (not even the curly brackets) - the default action is to print the entire line.
95 95
96 96
97 **AWK's Regular Expression Syntax** 97 **AWK's Regular Expression Syntax**
98 98
99 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. 99 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.
100 100
101 - **( ) { } [ ] . * ? + \ ^ $** are all special characters. **\\** can be used to "escape" a special character, allowing that special character to be searched for. 101 - **( ) { } [ ] . * ? + \ ^ $** are all special characters. **\\** can be used to "escape" a special character, allowing that special character to be searched for.
102 - **^** matches the beginning of a string(but not an internal line). 102 - **^** matches the beginning of a string(but not an internal line).
103 - **(** .. **)** groups a particular pattern. 103 - **(** .. **)** groups a particular pattern.
104 - **{** n or n, or n,m **}** specifies an expected number of repetitions of the preceding pattern. 104 - **{** n or n, or n,m **}** specifies an expected number of repetitions of the preceding pattern.
105 105
106 - **{n}** The preceding item is matched exactly n times. 106 - **{n}** The preceding item is matched exactly n times.
107 - **{n,}** The preceding item ismatched n or more times. 107 - **{n,}** The preceding item ismatched n or more times.
108 - **{n,m}** The preceding item is matched at least n times but not more than m times. 108 - **{n,m}** The preceding item is matched at least n times but not more than m times.
109 109
110 - **[** ... **]** 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**. 110 - **[** ... **]** 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**.
111 - **.** Matches any single character except a newline. 111 - **.** Matches any single character except a newline.
112 - ***** The preceding item will be matched zero or more times. 112 - ***** The preceding item will be matched zero or more times.
113 - **?** The preceding item is optional and matched at most once. 113 - **?** The preceding item is optional and matched at most once.
114 - **+** The preceding item will be matched one or more times. 114 - **+** The preceding item will be matched one or more times.
115 - **^** has two meaning: 115 - **^** has two meaning:
116 - matches the beginning of a line or string. 116 - matches the beginning of a line or string.
117 - indicates negation in a character class. For example, [^...] matches every character except the ones inside brackets. 117 - indicates negation in a character class. For example, [^...] matches every character except the ones inside brackets.
118 - **$** matches the end of a line or string. 118 - **$** matches the end of a line or string.
119 - **\|** Separates alternate possibilities. 119 - **\|** Separates alternate possibilities.
120 120
121 @REFERENCES@ 121 @REFERENCES@
122 ]]> 122 ]]>
123 </help> 123 </help>
124 </tool> 124 </tool>