awk book

Awk array statistics, awk Array Process the following file content, retrieve the domain name andDomain Name countSorting: (Baidu and sohu interview questions) 1 http://www.etiantian.org/index.html2 http://www.etiantian.org/1.html3 http://post.etiantian.org/index.html4 http://mp3.etiantian.org/index.html5 http://www.etiantian.org/3.html6 http://post.etiantian.org/2.html Results: mp3.etiantian.org 1post.etian

-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";mso-ansi-language:#0400;mso-fareast-language:#0400;mso-bidi-language:#0400;}--> 1. Introduction Retrieve various types of data from the original data file, remove the header, and output it to different files named according to the data type. This sorting and formatting task is a basic part of data analysis and processing. You can use awk, grep/SED/

Awk call Syntax: Awk [-F -- Where:Ch: Field-separator character.Pgm: Awk command-line program.Pgm file: File containing an Awk program.Vars: Awk variable initializations. Data file: Input data file. Note: 1. The data file is optional. If not specified,

Awk string function (2), awk string Function The substr function returns a substring starting from the specified position of the string. If the length of the substring is specified, the corresponding part of the string is returned. If the specified length exceeds the actual range of the string, the actual content is returned.FormatSubstr (string, starting position) Substr (string, starting position, substri

Awk programming model and awk Programming It is important to understand the basic model that awk provides to programmers. Learning awk is easier than learning other programming languages because awk provides programmers with well-defined and useful models. The

format of this Program Statement segment is: 'Pattern' The pattern parameter can be any of the regular expressions of egrep. It can be made up of the syntax/RE/and some style matching techniques. Similar to SED, you can also use "," to separate the two formulas to select a certain range. For details about the matching, refer to the appendix. If you still don't understand it, find a Unix book to learn grep and sed (I learned the matching technology wh

A Basic introduction1.awk:Awk is a powerful text analysis tool that is irreplaceable in the processing of text files and generating reports. Awk considers text files to be structured, which defines each input row as a single record, each string in the row is defined as a field (segment), and the domain and domain are split using a delimiter.2. Functions: Flow control, mathematical operations, Process Control, built-in variables and functions, loops an

Awk usage: awk 'pattern' {action} 'variable name meaning ARGC command line variable number ARGV command line variable element array FILENAME current input file name FNR current file record number FS input domain separator, default is a space RS input record delimiter NF number of fields in the current record NR number of records so far OFS output domain separator ORS output record separator 1

). ORS The output record delimiter (the default value is a line break ). RLENGTH The length of the string matched by the match function. RS Record separator (a line break by default ). RSTART The first position of the string matched by the match function. SUBSEP Array subscript separator (default value: \ 034 ). Awk calls each row ending with a line break a record. Record separator: th

A regular expression: a regular expression (or regular expression, called re) is a text pattern consisting of ordinary characters (such as characters A through Z) and special characters (called metacharacters). This pattern describes one or more strings to match when looking up a text body. A regular expression, as a template, matches a character pattern to the string you are searching for. Simply put, the regular expression is the method of processing the string, it is the behavior unit to cond

Simple examples of Text Analysis Tool awk and text awk Create a file: vim hi Take 2nd fields and 3rd fields: Awk '{print $2, $3}' hi note {}, CommaWill be converted to a space in the output. Character Description: Display the entire line: Field separator:-F Built-in variable: NF: number of fields. $ NF indicates the last field. NR: number of rows /

The subscript of the awk associated array, and the subscript of the awk associated array For more information about using variables as array indexes, see examples. Example$ Cat employees Tom Jones 4424 5/12/66 543354 Mary Adams 5346 11/4/63 28765 Sally Chang 1654 7/22/54 650000 Billy Black 1683 9/23/44 336500 $ awk '{name [x ++] = $2} END {for (I = 0; I 0 J

Awk control function, awk Function Example$ Cat datafile Northwest NW Joel Craig 3.0. 98 3 4 Western WE Sharon Kelly 5.3. 97 5 23 Southwest SW Chris Foster 2.7. 8 2 18 Southern SO May Chin 5.1. 95 4 15 Southeast SE Derek Johnson 4.0. 7 4 17 Eastern EA Suan Beal 4.4. 84 5 20 Northeast ne tj Nicholas 5.1. 94 3 13 North NO Val Shultz 4.5. 89 5 9 Central CT Sheri Watson 5.7. 94 5 13 $

The awk Passes parameters to the script (2). The awk script Passes parameters. An important limitation of command line parameters is that they are unavailable during the in process. That is, they are available only after the first line is entered. Why? This is a confusing part. Parameters passed from the command line are processed like file names. The value assignment operation is performed only when the va

Awk processes multiple rows of records and awk processes multiple rows The records of input files used in all our examples are composed of a single row. In this section, we will demonstrate how to read a record, and each field in the record is composed of a single row. We have learned an example of a file that processes the name and address. Let's assume that the same data is saved in a block format file. I

AWK and awk commands VariableDescription N the nth field of the current record. The fields are separated by FS. 0Complete input records.ARGCThe number of command line parameters.ARGINDLocation of the current file in the command line (starting from 0 ).ARGVArray containing command line parameters.CONVFMTNumber conversion format (default value: %. 6g)ENVIRONEnvironment Variable join array.ERRNODescript

Each awk statement consists of a pattern and corresponding actions. The execution of the pattern control rule in the awk-a rule is executed when its pattern matches the current input record. Special begin and end modes: They provide awk ProgramStart and end actions, The begin and end rules must have actions. They are executed only once in the program. For ex

Multi-dimensional awk array and multi-dimensional awk Although the awk command does not claim to support multi-dimensional arrays, it provides a method to define multi-dimensional arrays. Awk defines multi-dimensional arrays by concatenating multiple subscripts into strings. subscripts are separated by the value of the

Argc, argv # Awk ProgramThe available command line parameters are stored in the argv array. Argc is the number of command line parameters. Argind # The index of the currently processed file in argv. Each time gawk opens a new data file, it sets argind to the index in argv of the file name. That is to say, when gawk is processing files, 'filename = argv [argind] 'is always true. Environ # A joint array used to store environment variables. The dir

Tags: awkHttp://www.cnblogs.com/ginvip/p/6352157.htmlThis is a blog I found, the content of awk is written very well, need to seeawk about! No.(1) Take odd lines[[email protected] shell]# SEQ 10 | awk ' I=!i '13579(2) Take even lines[[email protected] shell]# SEQ 10 | awk '! (i=!i) '246810(3) SEQ 10 not after 4 lines[[email protected] shell]# SEQ 10 | Head-n-4123