AwkChannelWiki: Search for: "number"

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Adler32Checksum
As documented in the [[http://en.wikipedia.org/wiki/Adler-32 | Adler-32 Wikipedia article]]. {{{ awk . . . be 5552 when almost every # modern awk has numbers with at least 53 bits of precision, but # if . . . that our keys # here are strings; if they were numbers, we would also # have to convert those numbers . . .
4K - last updated 2008-12-31 12:05 UTC by pgas

AllAboutGetline
//Editor's notes: The article was originally posted on the comp.lang.awk newsgroup, and can still be . . . is limited in its recursion depth to the total number of open files the OS permits at one time. === . . . the record that contains some pattern, e.g. the number 3: {{{ sh $ cat file line 1 line 2 line 3 line . . . we also have to print the word "Eureka" if the number 4 appears in the input file. With the getline . . . no longer need to print the 5th record after the number 3 but still have to do the Eureka on 4. With . . .
16K - last updated 2009-02-15 22:14 UTC by waldner

AwkDc
This is an awk implementation of the [http://www.gnu.org/software/bc/manual/dc-1.05/html_mono/dc.html|dc] . . . for the GNU extensions. awk native internal numbers will be used in this first version, with the . . . LargestAccurateNumber being an implementation-dependent value (though . . . integration of fast-path cases where native awk numbers can be used instead of bignums for speed gains . . . # FIXME: this will break horribly when the number # on the TOS is not an integer - catch this . . .
12K - last updated 2008-07-17 14:47 UTC by gnomon

AwkGuide
** Work in Progress ** {{{ import from Mark Hobley's wiki }}} <toc> ---- == Overview * [[Overview]] . . . * [[file]] handling * [[floating point]] numbers * [[for loop]]s * [[foreach]] loops * [[FS]] . . . * [[NF]] * [[nudge operator]]s * [[number]]s * [[operator]]s * [[output]] * [[parentheses]] . . .
4K - last updated 2011-08-14 15:57 UTC by markhobley

AwkOnWindows
[[AwkOnWindows|This page]] lists available versions of awk for ms windows.\\ Example: //awk /foo/{print(NR,$0)} . . . containing //foo//\\ preceded by the line number.\\ If new to awk, start here [[HomePage|AwkChannelWiki]].\\ . . .
2K - last updated 2010-10-24 09:39 UTC by g0pher

AwkTips
<toc> ---- == Be idiomatic! In this paragraph, we give some hints on how to write more idiomatic . . . print $0}' }}} That works, but there are a number of things to note. The first thing to note is . . . the line awk '$0 = NR" "$0' # prepends line numbers (assignments are valid in conditions) awk '!a[$0]++' . . . line. The special variable NR stores the total number of input records read so far, regardless of . . . terminates. Another variable, FNR, stores the number of records read //from the current file being . . .
31K - last updated 2009-03-24 16:54 UTC by waldner

Backreferences
The usual (and correct) answer for backreferences in awk (for example, the answer you can get on #awk . . . the third parameter is much like sed's match number specification in the s/pattern/replacement/ . . . command: it can either be a number, indicating to replace only that specific match, . . .
3K - last updated 2010-12-30 06:53 UTC by ppp089210039107.dsl.hol.gr

BeforeAfterMatch
Problem: print the Nth record before or after a certain regular expression matches or, alternativley, . . . approach could be to use a hash to store the numbers of the records to print: i) Print the Nth record . . .
3K - last updated 2009-02-28 20:38 UTC by waldner

CAWKLib
=CAWKLib CAWKlib is a library of functions for for awk intended to be used with preprocessors/wrappers . . . -- return the length of an array (meaning the number of elements/values/indices) *ary_width() -- . . . return the width of an array (meaning the number of "dimensions" in a multi-dimensional array) . . . at index 'i' *str_repeat() -- repeats a string x number of times (thanks again Ben) *str_repeat_to() . . .
5K - last updated 2015-01-29 10:14 UTC by 108-243-116-77.lightspeed.cicril.sbcglobal.net

command line parameter
The [[awk]] extraction and reporting language uses traditional conventions for accessing command line . . . are stored in the [[array]] ARGV, and the number of parameters are stored in the [[scalar]] variable . . .
1K - last updated 2011-06-25 05:49 UTC by pgas

ComparingTwoFiles
Sometimes it is useful to compare two files. To do this in awk, the trick is to load the data from the . . . * //FNR == NR//: This test is true when the number of records is equal to the number of records . . . for the second file NR will be equal to the number of lines of file1 + FNR. * //arr[$0]//: This . . .
2K - last updated 2011-08-25 00:35 UTC by steve

ContextGrep
The following snippets print matching lines with surrounding context lines, like GNU grep's **grep -A . . . (a regex to match), and **After** (the number of lines to print after each match). {{{ awk . . . should be printed. It's possible to minimize the number of lines saved by deleting extra saved lines . . . the variables **Pattern** and **Before** (number of lines before) to be set: {{{ awk $0 ~ Pattern . . . the variables **Pattern** and **Context** (number of lines to print before and after a match): . . .
3K - last updated 2011-07-01 08:32 UTC by pgas

ConvertHexToFloatingPoint
This code uses [[gawkism|gawk specific features]], such as the [[http://www.gnu.org/manual/gawk/html_node/Strtonum-Function.html][strtonum]] . . . = 0 bias=127 # convert the character bytes into numbers i3=strtonum("0x" b3) i2=strtonum("0x" b2) i1=strtonum("0x" . . . from raw to ieee 754 float32 # # x is the input number, 4 bytes assumed ######################################## . . . 2^exponent # factor in the sign of the original number if(sign != 0) fval *= -1 return fval } BEGIN . . .
3K - last updated 2010-06-23 19:49 UTC by john b

dollar
== Prefixing field numbers == The dollar symbol can be used to prefix [[field]] numbers: == Regular expression . . .
1K - last updated 2010-11-28 10:46 UTC by markhobley

dollarint
A [[dollar]] sign and followed by an [[integer]] are used to refer to [[field]]s within the current [[record]]: . . . {{{ awk { print $3 } # output field number three }}} Though you might consider $3 as a . . . is the field reference operator and 3 is just a number that tells awk you want to reference the third . . . C it behaves like the * on a pointer. == Field numbers are not limited to single digits == Unlike . . . digits: {{{ awk { print $123 } # output field number 123 }}} == Field numbers do not need to be constant . . .
3K - last updated 2011-06-25 05:28 UTC by pgas

enumeration
The [[awk]] extraction and reporting language does not directly support enumeration. However, it is possible . . . to simulate enumberation by using a [[variable]] and [[nudge]] operator . . .
1K - last updated 2011-05-27 15:28 UTC by markhobley

Features of awk
The [[awk]] utility: * treats lines of a text as database records, which can be divided into fields. . . . * uses [[filename association]] rather than numbered streams for file input and output * supports . . .
1K - last updated 2011-05-27 15:33 UTC by markhobley

field
In [[awk]] all [[input]] is separated into [[record]]s and each [[record]] is further divided into fields. . . . operator. {{{ awk { print $3 } # output field number three { print $12 } # output field number twelve . . .
1K - last updated 2011-06-25 05:31 UTC by pgas

field reference
== The field reference operator == The [[dollar]] symbol acts as a unary *field reference operator* and . . . is followed by a number or expression that gives a [[field]] number . . . record]]: {{{ { print $3 } # output field number three }}} === Field numbers are not limited . . . parameters in the Unix shell, [[field]] numbers are not limited to single digits: {{{ { print . . . $123 } # output field number 123 }}} ==== Using a variable name to specify . . .
2K - last updated 2011-06-28 09:12 UTC by markhobley

FileAndBitJoinClone
== Problem Description This was difficult to hash out. Eventually the task was described as, "for each . . . field on each line of bit.txt is simply the line number - the problem becomes quite easy. == The Code . . . that first field is supposed to be the line number, this assumption # is more or less reasonable; . . .
7K - last updated 2009-03-08 16:26 UTC by waldner

FindAllIndices
Sometimes it is useful to find the index of every occurrence of a given character in a string. Let's . . . have a list of positions that point to sequence numbers; # find the index of every backslash character; . . . doublequotes, skipping the marked ones. Each odd-numbered index indicates the beginning of a doublequoted . . . = i return j } }}} The function returns the number of instances found as a convenience (gsub() . . .
2K - last updated 2011-07-05 10:53 UTC by pgas

FindAllMatches
This bit of code will match all non-overlapping instances of a given pattern in a string and will store . . . the matches in the given array. It returns the number of patterns found. This duplicates some of the . . .
2K - last updated 2009-03-24 09:46 UTC by waldner

FIXES
[[FIXES]]        revised:   . . . (ENVIRON).\\ added -V to print version number (Mar 12, 1998)\\ \\ permit \n explicitly in . . . all files and pipes.\\ length(arrayname) returns number of elements (Jan 1, 2002)\\ subtle change to . . . split: if source is empty, number of elems\\     is . . .
6K - last updated 2014-01-15 23:17 UTC by g0ph3r

FNR
The *FNR* informative [[special variable]] is used to track the number of [[record]]s that have so far . . . when a new file is started. === Adding line numbers to a file === The FNR [[special variable]] . . . be wielded to give a simple way of adding line numbers to a file using [[awk]]: awk '{print FNR,$0 . . .
1K - last updated 2011-05-08 11:04 UTC by markhobley

ForceNumeric
These are the canonical, work-in-all-versions snippets. There are many others, most longer, some shorter . . . less portable). To compare two variables as numbers ONLY, use {{{ awk if (0+var1 == 0+var2) }}} . . .
1K - last updated 2008-11-26 12:43 UTC by pgas

Frequently Asked Questions
Some entries of this page have been copied from the [[comp.lang.awk_FAQ]]([[http://awk.freeshell.org/comp.lang.awk_FAQ#toc29|Credits]]) . . . Edit this answer]] ---- == I'm trying to print a number, why do I get 1e+06 instead of 1000001.10? <include . . . "PrintingNumbers"> [[http://awk.freeshell.org/?action=edit;id=PrintingNumbers| . . . ---- == How do I find the LargestAccurateNumber that my awk can use? <include "LargestAccurateNumber"> . . . Edit this answer]] ---- == Why would anyone . . .
3K - last updated 2015-09-08 08:46 UTC by pgas

getline
The *getline* command can obtain input from any number of files and does not require a command line parameter . . .
1K - last updated 2011-05-02 20:14 UTC by markhobley

HomePage
This wiki is maintained by regulars from the **#awk** channel on **[[https://libera.chat/|irc.libera.chat]]** . . . for the difference of two text strings * PrimeNumberSieve implemented in two slightly different ways, . . . with comparative performance numbers under a variety of implementations * ComparingTwoFiles . . . IEE754 Floating point back into a floating point number * [[GeoLocation]] Find where your IP address . . .
5K - last updated 2023-06-26 04:15 UTC by HappMacDonald

HomePageJapanese
Here is the Japanese page for [[HomePage]]. 英語のページは[[HomePage|こちら]]です。この wiki は **[[http://www.freenode.net|irc.freenode.net]]** . . . つのテキスト文字列の間の差の数を数えるレーベンシュタイン距離]] * [[PrimeNumberSieve|実装の違いによる比較ができるように 2 つの少し異なる方法で実装した素数]] . . .
5K - last updated 2008-10-19 07:34 UTC by hi saito

Inicio
Este wiki es mantenido por los usuarios del cenal **#awk** en **[[http://www.freenode.net|irc.freenode.net]]**. . . . for the difference of two text strings * PrimeNumberSieve implemented in two slightly different ways, . . . with comparative performance numbers under a variety of implementations * ComparingTwoFiles . . .
7K - last updated 2009-02-12 23:31 UTC by fcr

input
The [[awk]] utility can take its input from [[standard input]] or from [[file]]s. If no input files are . . . An informative variable that provides the record number within the current file | [[FS]] | A control . . . | An informative variable that provides the number of fields within the current record | [[NR]] . . . An informative variable that provides the total number of records processed | [[RS]] | A control variable . . .
2K - last updated 2011-05-19 22:40 UTC by markhobley

LargestAccurateNumber
Most [[awk]] implementations use floating point double precision to represent every kind of numeric value. . . . cause worry when one is trying to sum up large numbers in very large log files: when is it safe to . . . rely on awk's numbers and when should one shell out to dc or bc for . . . loss of accuracy is to find out when some number N is no longer distinct from N+1: {{{ sh awk . . . "accurate"}' }}} This will print out a list of numbers. The largest reliable value that this process . . .
3K - last updated 2013-04-12 14:52 UTC by ttmrichter

LastField
awk performs a number of actions automatically when it parses lines: it updates the variable NF, which . . . contains the number of fields on a line; and it parses the record . . . is the field reference operator and 1 is just a number that tells awk you want to reference the first . . . first field. Since the variable NF contains the number of fields on a line, and since fields are indexed . . .
2K - last updated 2009-02-05 22:43 UTC by firebush.stsci.edu

length
== Usage == === length ([ STRING ]) === The **length** function returns the number of characters within . . .
1K - last updated 2011-06-25 05:11 UTC by pgas

LoopOnFields
Fields are numbered from 1 to NF, so you can easily use a for loop, and the derefence operator, for instance . . .
1K - last updated 2009-03-17 21:09 UTC by waldner

Mark Hobley
Welcome to this wiki! Thanks a lot for your contribution. As you seem to start a whole awk guide, maybe . . . I also removed the links on the LargestAccurateNumber page, I think that having all these links are . . .
1K - last updated 2009-01-27 08:04 UTC by pgas

modulus
The [[dyadic]] modulus [[operator]], represented by a [[percent]] sign is used to return the remainder . . . 3 (the remainder of 15 divided by 4) == Negative Numbers == The modulus operator may be used with negative . . . numbers: print -13 % 7 # -6 == Modulus Combination . . .
1K - last updated 2011-06-07 00:41 UTC by markhobley

NF
= Number of Fields = The [[special variable]] NF holds the number of [[field]]s in the [[current record]]. . . .
1K - last updated 2011-05-28 15:14 UTC by markhobley

nudge operator
The *nudge operators* can be used to [[increment]] or [[decrement]] the value of their [[operand]]s, . . . the [[operand]]s must be [[variable name]]s: {{{ number++ # increment number-- # decrement }}} == Nudge . . . [[expression]] is evaluated. {{{ # preincrement number = 5 result = ++number # result is 6 and number . . . is 6 # predecrement number = 5 result = --number # result is 4 and number . . . has been evaluated: {{{ # postincrement number = 5 result = number++ # result is 5 but number . . .
3K - last updated 2011-03-20 13:18 UTC by markhobley

number
== _Numbers can be expressed as integers or floating point values_ In [[awk]], numbers can be expressed . . . [integer]]s or as [[floating point]] values. == _Numbers should be specified in decimal_ The [[awk]] . . . does not provide facilities for specifying numbers in non [[decimal]] bases. However numerical . . . or [[hexadecimal]]. == _Positive and negative numbers_ Negative numbers in awk must be prefixed with . . . a minus numbersign operator: number = -5 It is also possible . . .
1K - last updated 2011-03-06 22:33 UTC by markhobley

number sign operators
== _Number sign operators_ === _Negative numbers_ The *minus symbol* may be used as a [[unary]] operator . . . in [[negative]] number representation: number = -5 # -5 is negative . . . === _Positive numbers_ The *plus symbol* may be used as a [unary] . . . operator in [[positive]] number representation. This form is generally not required, . . . because numbers are [[positive]] by default: number = +6 # . . .
1K - last updated 2011-02-28 12:39 UTC by pgas

operator
The [[awk]] programming language provides a series of *operators* that allow [[value]]s and [[variable]]s . . . [[dyadic]] or [[ternary]] form, depending on the number of [[operand]]s that they utilize. == assignment . . . manipulating [[integer]] and [[floating point]] numbers. == string operators * [[string operator]]s . . . == nudge operators * [[nudge operator]]s == number sign operators * [[number sign operators]] == . . .
3K - last updated 2011-05-24 22:19 UTC by markhobley

output
== output == === standard output === === output to files === The [[awk]] programming language uses a . . . system of named files, rather than numbered [[stream]]s for output channels. Output to . . .
1K - last updated 2010-11-16 00:44 UTC by markhobley

precedence
The [[awk]] programming language uses rules of *precedence* to determine the order in which [[operator]]s . . . the value outside. {{{ BEGIN { # Changing the number variable in the middle of the expression may . . . introduce side effects result = (number = 4) + number # This expression may produce . . . | Notes | 1 | 12 | The first component is the number 12. This is also the first element | 2 | + | . . . element | 4 | 2 | The fourth component is the number 2. This is the first element of the second element . . .
7K - last updated 2013-04-11 06:58 UTC by markhobley

PrimeNumberSieve
This is the standard sieve of Eratosthenes implemented in portable awk. The running time of the bare . . . time, no exceptions, as per the spec). Arrays, numbered fields and the {{{substr()}}} built-in are . . . O(1) references; of the three, only arrays and numbered fields offer O(1) assignment as well; and . . . of those two, numbered fields //ought// to have a lower constant . . . arrays, since no hashing is required. But do numbered fields deliver the expected performance benefits? . . .
4K - last updated 2008-06-19 05:56 UTC by gnomon

PrintASingleQuote
This question gets asked often enough that it deserves its own answer. This common question doesn't actually . . . the [[escape sequence]]s have a corresponding number. gawk features [[http://www.gnu.org/software/gawk/manual/html_node/Printf-Ordering.html|a . . .
5K - last updated 2015-07-05 09:45 UTC by pitman

PrintingNumbers
Use printf and a format string instead of print, some examples: {{{ awk BEGIN { printf "%f", 1000001.10 . . . contains %.6g by default, when it has to print a number: {{{ sh $ echo 12.123123124 | awk '{print $1;print . . . 12.1231 # same as printf "%.6g",$1 ($1+0 is a number) 12.123 # same as printf "%.5g",$1 }}} Take . . . by default, while it would be considered as a number in a boolean expression see [[truth]] There . . . is also another conversion that happens when a number is transformed into a string but not by print, . . .
2K - last updated 2009-03-04 12:34 UTC by pgas

RangeOfFields
Printing a range of fields - all fields but the first, for examples, or fields 3 through 8 - is a surprisingly . . . the line ("n" must be replaced by the actual number of fields that you want to remove). If you want . . . single space. {{{ bash # You could hardcode the numbers, replacing "s" and "e" in the code. # If you . . .
10K - last updated 2015-09-08 09:52 UTC by pgas

SedFAQ
<toc> ---- == I have a line like "abdcgfjeuPATTERNfjfhghj", I want to get the PATTERN part, why . . . but after sed is done you'll find an equal number of .txt.bak files created by sed that are copies . . . an arbitrary regexp, but occurs a known, fixed number of times per line, then you can do this (example . . . is an arbitrary regexp and occurs an unknown number of times, then, to solve the problem with sed . . . that means we have pulled out the required number of occurrences, and we quit. Easier to look . . .
34K - last updated 2010-02-14 17:56 UTC by waldner

special variable
Some [[variable]] names have a special meaning to the awk interpreter. == List of special variables == . . . | An informative variable that provides the number of records read from current file | [[FS]] | . . . | An informative variable that provides the number of fields within the current record | [[NR]] . . . An informative variable that provides the total number of records read so far | [[OFMT]] | A control . . .
2K - last updated 2011-06-25 05:46 UTC by pgas

StyleSheet
body { background-color:#FFF; color:#000; margin:1em 2em; } textarea { width:100%; } a:link { color:#00F; . . . } a.edit, div.footer, form, span.gotobar, a.number span { display:none; } a[class="url number"]:after, . . . a[class="inter number"]:after { content:"[" attr(href) "]"; } a[class="local . . . number"]:after { content:"[" attr(title) "]"; } img[smiley] . . .
5K - last updated 2008-06-19 16:46 UTC by pgas

truth
== Boolean Truth == A **boolean [[expression]]** has only two outcomes: **true** or **false**. In [[awk]], . . . "true"}else{print "false"}}' false # $1 is the number 0 }}} ==== Taking zero from a variable If a . . . make sure that your expression is evaluated as a number or as a string you can add 0 or concatenate . . . null string, respectively: {{{ awk var + 0 # a number it will always be false if var contains 0 or . . . "0" var == 0 # var is evaluated as a number var "" # a string true if non null even if it . . .
3K - last updated 2013-02-20 17:34 UTC by markhobley

variable
A '''variable''' is a symbolic name associated with a [[value]]. A variable acts as a container and the . . . evaluates to [[zero]] when [[convert]]ed to a [[number]]. == Initialization within a begin block is . . .
3K - last updated 2012-04-22 11:42 UTC by unregistered

WartAndWishList
Awk is a wonderful language! That said, there are a few annoying bits... == The Good * well-documented . . . of querying the type of a variable: strings and numbers get automatically converted from type to type. . . . **only** be strings. This means that even when numbers are used to index into an array, the numbers . . . a user function is invoked with a mismatched number of parameters, so there is a convention to list . . . * Awk arrays can only contain strings and numbers, and can only be indexed by strings. Arrays . . .
7K - last updated 2009-04-13 18:39 UTC by goedel

WhichIsBetter
This comes up so often that it deserves a page on its own. **NEVER**, **EVER** ask computer people whether . . . by your system Please note that, despite their number, some of the qualities listed above are still . . . Kde's interface is confusing because of the high number of customizations and options it offers. Again, . . .
5K - last updated 2009-07-12 09:13 UTC by host-87-74-84-72.dslgb.com

56 pages found.