Hello,
On 2019-10-08 12:36 a.m., Peng Yu wrote:
The following example shows that version sort is not natural sort. Is
natural sort supported in by `sort`?
There is no such thing as "THE correct natural sort" order...
$ printf '%s\n' 1G13 1.02 | LC_ALL=C sort -k 1,1V # The result order
should have been reversed.
... therefore "should have" is simply incorrect expectation.
You might think it "should" be one way, and other implementations
think it "should" be another way.
For more details, please see the attached HTML file for details.
(this HTML file is a new chapter of the coreutils manual that will be
included in the next release. The source texinfo is here:
https://git.savannah.gnu.org/cgit/coreutils.git/tree/doc/sort-version.texi
).
regards,
- assaf
#[1]Version sort ordering
1 Version sort ordering
• [2]Version sort overview:
• [3]Implementation Details:
• [4]Differences from the official Debian Algorithm:
• [5]Advanced Topics:
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Next: [6]Implementation Details, Up: [7]Version sort ordering
1.1 Version sort overview
version sort ordering (and similarly, natural sort ordering) is a
method to sort items such as file names and lines of text in an order
that feels more natural to people, when the text contains a mixture of
letters and digits.
Standard sorting usually does not produce the order that one expects
because comparisons are made on a character-by-character basis.
Compare the sorting of the following items:
Alphabetical sort: Version Sort:
a1 a1
a120 a2
a13 a13
a2 a120
version sort functionality in GNU coreutils is available in the ‘ls
-v’, ‘ls --sort=version’, ‘sort -V’, ‘sort --version-sort’ commands.
• [8]Using version sort in GNU coreutils:
• [9]Origin of version sort and differences from natural sort:
• [10]Correct/Incorrect ordering and Expected/Unexpected results:
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Next: [11]Origin of version sort and differences from natural sort, Up:
[12]Version sort overview
1.1.1 Using version sort in GNU coreutils
Two GNU coreutils programs use version sort: ls and sort.
To list files in version sort order, use ls with -v or --sort=version
options:
default sort: version sort:
$ ls -1 $ ls -1 -v
a1 a1
a100 a1.4
a1.13 a1.13
a1.4 a1.40
a1.40 a2
a2 a100
To sort text files in version sort order, use sort with the -V option:
$ cat input
b3
b11
b1
b20
alphabetical order: version sort order:
$ sort input $ sort -V input
b1 b1
b11 b3
b20 b11
b3 b20
To sort a specific column in a file use -k/--key with ‘V’ ordering
option:
$ cat input2
1000 b3 apples
2000 b11 oranges
3000 b1 potatoes
4000 b20 bananas
$ sort -k2V,2 input2
3000 b1 potatoes
1000 b3 apples
2000 b11 oranges
4000 b20 bananas
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Next: [13]Correct/Incorrect ordering and Expected/Unexpected results,
Previous: [14]Using version sort in GNU coreutils, Up: [15]Version sort
overview
1.1.2 Origin of version sort and differences from natural sort
In GNU coreutils, the name version sort was chosen because it is based
on Debian GNU/Linux’s algorithm of sorting packages’ versions.
Its goal is to answer the question “which package is newer,
firefox-60.7.2 or firefox-60.12.3 ?”
In coreutils this algorithm was slightly modified to work on more
general input such as textual strings and file names (see
[16]Differences from the official Debian Algorithm).
In other contexts, such as other programs and other programming
languages, a similar sorting functionality is called [17]natural sort.
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Up: [19]Version sort overview
1.1.3 Correct/Incorrect ordering and Expected/Unexpected results
Currently there is no standard for version/natural sort ordering.
That is: there is no one correct way or universally agreed-upon way to
order items. Each program and each programming language can decide its
own ordering algorithm and call it ’natural sort’ (or other various
names).
See [20]Other version/natural sort implementations for many examples of
differing sorting possibilities, each with its own rules and
variations.
If you do suspect a bug in coreutils’ implementation of version-sort,
see [21]Reporting bugs or incorrect results on how to report them.
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Next: [22]Differences from the official Debian Algorithm, Previous:
[23]Version sort overview, Up: [24]Version sort ordering
1.2 Implementation Details
GNU coreutils’ version sort algorithm is based on [25]Debian’s
versioning scheme, specifically on the "upstream version" part.
This section describes the ordering rules.
The next section ([26]Differences from the official Debian Algorithm)
describes some differences between GNU coreutils implementation and
Debian’s official algorithm.
• [27]Version-sort ordering rules:
• [28]Version sort is not the same as numeric sort:
• [29]Punctuation Characters:
• [30]Punctuation Characters vs letters:
• [31]Tilde ‘~’ character:
• [32]Version sort ignores locale:
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Next: [33]Version sort is not the same as numeric sort, Up:
[34]Implementation Details
1.2.1 Version-sort ordering rules
The version sort ordering rules are:
1. The strings are compared from left to right.
2. First the initial part of each string consisting entirely of
non-digit characters is determined.
1. These two parts (one of which may be empty) are compared
lexically. If a difference is found it is returned.
2. The lexical comparison is a comparison of ASCII values
modified so that:
1. all the letters sort earlier than all the non-letters and
2. so that a tilde sorts before anything, even the end of a
part.
3. Then the initial part of the remainder of each string which
consists entirely of digit characters is determined. The numerical
values of these two parts are compared, and any difference found is
returned as the result of the comparison.
1. For these purposes an empty string (which can only occur at
the end of one or both version strings being compared) counts
as zero.
4. These two steps (comparing and removing initial non-digit strings
and initial digit strings) are repeated until a difference is found
or both strings are exhausted.
Consider the version-sort comparison of two file names: foo07.7z and
foo7a.7z. The two strings will be broken down to the following parts,
and the parts compared respectively from each string:
foo vs foo (rule 2, non-digits characters)
07 vs 7 (rule 3, digits characters)
. vs a. (rule 2)
7 vs 7 (rule 3)
z vs z (rule 2)
Comparison flow based on above algorithm:
1. The first parts (foo) are identical in both strings.
2. The second parts (07 and 7) are compared numerically, and are
identical.
3. The third parts (‘.’ vs ‘a.’) are compared lexically by ASCII value
(rule 2.2).
4. The first character of the first string (‘.’) is compared to the
first character of the second string (‘a’).
5. Rule 2.2.1 dictates that "all letters sorts earlier than all
non-letters". Hence, ‘a’ comes before ‘.’.
6. The returned result is that foo7a.7z comes before foo07.7z.
Result when using sort:
$ cat input3
foo07.7z
foo7a.7z
$ sort -V input3
foo7a.7z
foo07.7z
See [35]Differences from the official Debian Algorithm for additional
rules that extend the Debian algorithm in coreutils.
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Next: [36]Punctuation Characters, Previous: [37]Version-sort ordering
rules, Up: [38]Implementation Details
1.2.2 Version sort is not the same as numeric sort
Consider the following text file:
$ cat input4
8.10
8.5
8.1
8.01
8.010
8.100
8.49
Numerical Sort: Version Sort:
$ sort -n input4 $ sort -V input4
8.01 8.01
8.010 8.1
8.1 8.5
8.10 8.010
8.100 8.10
8.49 8.49
8.5 8.100
Numeric sort (‘sort -n’) treats the entire string as a single numeric
value, and compares it to other values. For example, 8.1, 8.10 and
8.100 are numerically equivalent, and are ordered together. Similarly,
8.49 is numerically smaller than 8.5, and appears before first.
Version sort (‘sort -V’) first breaks down the string into digits and
non-digits parts, and only then compares each part (see annotated
example in Version-sort ordering rules).
Comparing the string 8.1 to 8.01, first the ‘8’ characters are compared
(and are identical), then the dots (‘.’) are compared and are
identical, and lastly the remaining digits are compared numerically (1
and 01) - which are numerically equivalent. Hence, 8.01 and 8.1 are
grouped together.
Similarly, comparing 8.5 to 8.49 - the ‘8’ and ‘.’ parts are identical,
then the numeric values 5 and 49 are compared. The resulting 5 appears
before 49.
This sorting order (where 8.5 comes before 8.49) is common when
assigning versions to computer programs (while perhaps not intuitive or
’natural’ for people).
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Next: [39]Punctuation Characters vs letters, Previous: [40]Version sort
is not the same as numeric sort, Up: [41]Implementation Details
1.2.3 Punctuation Characters
Punctuation characters are sorted by ASCII order (rule 2.2).
$ touch 1.0.5_src.tar.gz 1.0_src.tar.gz
$ ls -v -1
1.0.5_src.tar.gz
1.0_src.tar.gz
Why is 1.0.5_src.tar.gz listed before 1.0_src.tar.gz ?
Based on the [42]algorithm above, the strings are broken down into the
following parts:
1 vs 1 (rule 3, all digit characters)
. vs . (rule 2, all non-digit characters)
0 vs 0 (rule 3)
. vs _src.tar.gz (rule 2)
5 vs empty string (no more character in the file name)
_src.tar.gz vs empty string
The fourth parts (‘.’ and _src.tar.gz) are compared lexically by ASCII
order. The character ‘.’ (ASCII value 46) is smaller than ‘_’ (ASCII
value 95) - and should be listed before it.
Hence, 1.0.5_src.tar.gz is listed first.
If a different character appears instead of the underscore (for
example, percent sign ‘%’ ASCII value 37, which is smaller than dot’s
ASCII value of 46), that file will be listed first:
$ touch 1.0.5_src.tar.gz 1.0%zzzzz.gz
1.0%zzzzz.gz
1.0.5_src.tar.gz
The same reasoning applies to the following example: The character ‘.’
has ASCII value 46, and is smaller than slash character ‘/’ ASCII value
47:
$ cat input5
3.0/
3.0.5
$ sort -V input5
3.0.5
3.0/
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Next: [43]Tilde ‘~’ character, Previous: [44]Punctuation Characters,
Up: [45]Implementation Details
1.2.4 Punctuation Characters vs letters
Rule 2.2.1 dictates that letters sorts earlier than all non-letters
(after breaking down a string to digits and non-digits parts).
$ cat input6
a%
az
$ sort -V input6
az
a%
The input strings consist entirely of non-digits, and based on the
above algorithm have only one part, all non-digit characters (‘a%’ vs
‘az’).
Each part is then compared lexically, character-by-character. ‘a’
compares identically in both strings.
Rule 2.2.1 dictates that letters (‘z’) sorts earlier than all
non-letters (‘%’) - hence ‘az’ appears first (despite ‘z’ having ASCII
value of 122, much bigger than ‘%’ with ASCII value 37).
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Next: [46]Version sort ignores locale, Previous: [47]Punctuation
Characters vs letters, Up: [48]Implementation Details
1.2.5 Tilde ‘~’ character
Rule 2.2.2 dictates that tilde character ‘~’ (ASCII 126) sorts before
all other non-digit characters, including an empty part.
$ cat input7
1
1%
1.2
1~
~
$ sort -V input7
~
1~
1
1%
1.2
The sorting algorithm starts by breaking down the string into
non-digits (rule 2) and digits parts (rule 3).
In the above input file, only the last line in the input file starts
with a non-digit (‘~’). This is the first part. All other lines in the
input file start with a digit - their first non-digit part is empty.
Based on rule 2.2.2, tilde ‘~’ sorts before all other non-digits
including the empty part - hence it comes before all other strings, and
is listed first in the sorted output.
The remaining lines (1, 1%, 1.2, 1~) follow similar logic: The digit
part is extracted (1 for all strings) and compares identical. The
following extracted parts for the remaining input lines are: empty
part, %, ., ~.
Tilde sorts before all others, hence the line 1~ appears next.
The remaining lines (1, 1%, 1.2) are sorted based on previously
explained rules.
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Previous: [49]Tilde ‘~’ character, Up: [50]Implementation Details
1.2.6 Version sort uses ASCII order, ignores locale, unicode characters
In version sort, unicode characters are compared byte-by-byte according
to their binary representation, ignoring their unicode value or the
current locale.
Most commonly, unicode characters (e.g. Greek Small Letter Alpha U+03B1
‘α’) are encoded as UTF-8 bytes (e.g. ‘α’ is encoded as UTF-8
sequence 0xCE 0xB1). The encoding will be compared byte-by-byte, e.g.
first 0xCE (decimal value 206) then 0xB1 (decimal value 177).
$ touch aa az "a%" "aα"
$ ls -1 -v
aa
az
a%
aα
Ignoring the first letter (a) which is identical in all strings, the
compared values are:
‘a’ and ‘z’ are letters, and sort earlier than all other non-digit
characters.
Then, percent sign ‘%’ (ASCII value 37) is compared to the first byte
of the UTF-8 sequence of ‘α’, which is 0xCE or 206). The value 37 is
smaller, hence ‘a%’ is listed before ‘aα’.
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Next: [51]Advanced Topics, Previous: [52]Implementation Details, Up:
[53]Version sort ordering
1.3 Differences from the official Debian Algorithm
The GNU coreutils’ version sort algorithm differs slightly from the
official Debian algorithm, in order to accommodate more general usage
and file name listing.
• [54]Minus/Hyphen ‘-’ and Colon ‘:’ characters:
• [55]Additional hard-coded priorities in GNU coreutils' version sort:
• [56]Special handling of file extensions:
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Next: [57]Additional hard-coded priorities in GNU coreutils' version
sort, Up: [58]Differences from the official Debian Algorithm
1.3.1 Minus/Hyphen ‘-’ and Colon ‘:’ characters
In Debian’s version string syntax the version consists of three parts:
[epoch:]upstream_version[-debian_revision]
The epoch and debian_revision parts are optional.
Example of such version strings:
60.7.2esr-1~deb9u1
52.9.0esr-1~deb9u1
1:2.3.4-1+b2
327-2
1:1.0.13-3
2:1.19.2-1+deb9u5
If the debian_revision part is not present, hyphen characters ‘-’ are
not allowed. If epoch is not present, colons ‘:’ are not allowed.
If these parts are present, hyphen and/or colons can appear only once
in valid Debian version strings.
In GNU coreutils, such restrictions are not reasonable (a file name can
have many hyphens, a line of text can have many colons).
As a result, in GNU coreutils hyphens and colons are treated exactly
like all other punctuation characters (i.e., they are sorted after
letters. See Punctuation Characters above).
In Debian, these characters are treated differently than in coreutils:
a version string with hyphen will sort before similar strings without
hyphens.
Compare:
$ touch abb ab-cd
$ ls -v -1
abb
ab-cd
With Debian’s dpkg they will be listed as ab-cd first and abb second.
For further technical details see [59]bug35939.
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Next: [60]Special handling of file extensions, Previous:
[61]Minus/Hyphen ‘-’ and Colon ‘:’ characters, Up: [62]Differences from
the official Debian Algorithm
1.3.2 Additional hard-coded priorities in GNU coreutils’ version sort
In GNU coreutils’ version sort algorithm, the following items have
special priority and sort earlier than all other characters (listed in
order);
1. The empty string
2. The string ‘.’ (a single dot character, ASCII 46)
3. The string ‘..’ (two dot characters)
4. Strings start with a dot (‘.’) sort earlier than strings starting
with any other characters.
Example:
$ printf "%s\n" a "" b "." c ".." ".d20" ".d3" | sort -V
.
..
.d3
.d20
a
b
c
These priorities make perfect sense for ‘ls -v’: The special files dot
‘.’ and dot-dot ‘..’ will be listed first, followed by any hidden files
(files starting with a dot), followed by non-hidden files.
For ‘sort -V’ these priorities might seem arbitrary. However, because
the sorting code is shared between the ls and sort program, the
ordering rules are the same.
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Previous: [63]Additional hard-coded priorities in GNU coreutils'
version sort, Up: [64]Differences from the official Debian Algorithm
1.3.3 Special handling of file extensions
GNU coreutils’ version sort algorithm implements specialized handling
of file extensions (or strings that look like file names with
extensions).
This nuanced implementation enables slightly more natural ordering of
files.
The additional rules are:
1. A suffix (i.e., a file extension) is defined as: a dot, followed by
a letter or tilde, followed by one or more letters, digits, or
tildes (possibly repeated more than once), until the end of the
string (technically, matching the regular expression
(\.[A-Za-z~][A-Za-z0-9~]*)*).
2. If the strings contains suffixes, the suffixes are temporarily
removed, and the strings are compared without them (using the
[65]algorithm above).
3. If the suffix-less strings are identical, the suffix is restored
and the entire strings are compared.
4. If the non-suffixed strings differ, the result is returned and the
suffix is effectively ignored.
Examples for rule 1:
* hello-8.txt: the suffix is .txt
* hello-8.2.txt: the suffix is .txt (‘.2’ is not included because the
dot is not followed by a letter)
* hello-8.0.12.tar.gz: the suffix is .tar.gz (‘.0.12’ is not
included)
* hello-8.2: no suffix (suffix is an empty string)
* hello.foobar65: the suffix is .foobar65
* gcc-c++-10.8.12-0.7rc2.fc9.tar.bz2: the suffix is .fc9.tar.bz2
(.7rc2 is not included as it begins with a digit)
Examples for rule 2:
* Comparing hello-8.txt to hello-8.2.12.txt, the .txt suffix is
temporarily removed from both strings.
* Comparing foo-10.3.tar.gz to foo-10.tar.xz, the suffixes .tar.gz
and .tar.xz are temporarily removed from the strings.
Example for rule 3:
* Comparing hello.foobar65 to hello.foobar4, the suffixes (.foobar65
and .foobar4) are temporarily removed. The remaining strings are
identical (hello). The suffixes are then restored, and the entire
strings are compared (hello.foobar4 comes first).
Examples for rule 4:
* When comparing the strings hello-8.2.txt and hello-8.10.txt, the
suffixes (.txt) are temporarily removed. The remaining strings
(hello-8.2 and hello-8.10) are compared as previously described
(hello-8.2 comes first). (In this case the suffix removal algorithm
does not have a noticeable effect on the resulting order.)
How does the suffix-removal algorithm effect ordering results?
Consider the comparison of hello-8.txt and hello-8.2.txt.
Without the suffix-removal algorithm, the strings will be broken down
to the following parts:
hello- vs hello- (rule 2, all non-digit characters)
8 vs 8 (rule 3, all digit characters)
.txt vs . (rule 2)
empty vs 2
empty vs .txt
The comparison of the third parts (‘.’ vs ‘.txt’) will determine that
the shorter string comes first - resulting in hello-8.2.txt appearing
first.
Indeed this is the order in which Debian’s dpkg compares the strings.
A more natural result is that hello-8.txt should come before
hello-8.2.txt, and this is where the suffix-removal comes into play:
The suffixes (.txt) are removed, and the remaining strings are broken
down into the following parts:
hello- vs hello- (rule 2, all non-digit characters)
8 vs 8 (rule 3, all digit characters)
empty vs . (rule 2)
empty vs 2
As empty strings sort before non-empty strings, the result is hello-8
being first.
A real-world example would be listing files such as: gcc_10.fc9.tar.gz
and gcc_10.8.12.7rc2.fc9.tar.bz2: Debian’s algorithm would list
gcc_10.8.12.7rc2.fc9.tar.bz2 first, while ‘ls -v’ will list
gcc_10.fc9.tar.gz first.
These priorities make sense for ‘ls -v’: Versioned files will be listed
in a more natural order.
For ‘sort -V’ these priorities might seem arbitrary. However, because
the sorting code is shared between the ls and sort program, the
ordering rules are the same.
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Previous: [66]Differences from the official Debian Algorithm, Up:
[67]Version sort ordering
1.4 Advanced Topics
• [68]Comparing two strings using Debian's algorithm:
• [69]Reporting bugs or incorrect results:
• [70]Other version/natural sort implementations:
• [71]Related Source code:
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Next: [72]Reporting bugs or incorrect results, Up: [73]Advanced Topics
1.4.1 Comparing two strings using Debian’s algorithm
The Debian program dpkg (available on all Debian and Ubuntu
installations) can compare two strings using the --compare-versions
option.
To use it, create a helper shell function (simply copy & paste the
following snippet to your shell command-prompt):
compver() {
dpkg --compare-versions "$1" lt "$2" \
&& printf "%s\n" "$1" "$2" \
|| printf "%s\n" "$2" "$1" ; \
}
Then compare two strings by calling compver:
$ compver 8.49 8.5
8.5
8.49
Note that dpkg will warn if the strings have invalid syntax:
$ compver "foo07.7z" "foo7a.7z"
dpkg: warning: version 'foo07.7z' has bad syntax:
version number does not start with digit
dpkg: warning: version 'foo7a.7z' has bad syntax:
version number does not start with digit
foo7a.7z
foo07.7z
$ compver "3.0/" "3.0.5"
dpkg: warning: version '3.0/' has bad syntax:
invalid character in version number
3.0.5
3.0/
To illustrate the different handling of hyphens between Debian and
coreutils’ algorithms (see [74]Minus/Hyphen ‘-’ and Colon ‘:’
characters):
$ compver abb ab-cd 2>/dev/null $ printf "abb\nab-cd\n" | sort -V
ab-cd abb
abb ab-cd
To illustrate the different handling of file extension: (see
[75]Special handling of file extensions):
$ compver hello-8.txt hello-8.2.txt 2>/dev/null
hello-8.2.txt
hello-8.txt
$ printf "%s\n" hello-8.txt hello-8.2.txt | sort -V
hello-8.txt
hello-8.2.txt
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Next: [76]Other version/natural sort implementations, Previous:
[77]Comparing two strings using Debian's algorithm, Up: [78]Advanced
Topics
1.4.2 Reporting bugs or incorrect results
If you suspect a bug in GNU coreutils’ version sort (i.e., in the
output of ‘ls -v’ or ‘sort -V’), please first check the following:
1. Is the result consistent with Debian’s own ordering (using dpkg,
see [79]Comparing two strings using Debian's algorithm) ? If it is,
then this is not a bug - please do not report it.
2. If the result differs from Debian’s, is it explained by one of the
sections in [80]Differences from the official Debian Algorithm? If
it is, then this is not a bug - please do not report it.
3. If you have a question about specific ordering which is not
explained here, please write to [81][email protected], and provide
a concise example that will help us diagnose the issue.
4. If you still suspect a bug which is not explained by the above,
please write to [82][email protected] with a concrete example
of the suspected incorrect output, with details on why you think it
is incorrect.
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Next: [83]Related Source code, Previous: [84]Reporting bugs or
incorrect results, Up: [85]Advanced Topics
1.4.3 Other version/natural sort implementations
As previously mentioned, there are multiple variations on
version/natural sort, each with its own rules. Some examples are:
* Natural Sorting variants in [86]Rosetta Code.
* Python’s [87]natsort package (includes detailed description of
their sorting rules: [88]natsort - how it works).
* Ruby’s [89]version_sorter.
* Perl has multiple packages for natual and version sorts (each
likely with its own rules and nuances): [90]Sort::Naturally,
[91]Sort::Versions, [92]CPAN::Version.
* PHP has a built-in function [93]natsort.
* NodeJS’s [94]natural-sort package.
* In zsh, the [95]glob modifier *(n) will expand to files in natural
sort order.
* When writing C programs, the GNU libc library (glibc) provides the
[96]strvercmp(3) function to compare two strings, and
[97]versionsort(3) function to compare two directory entries
(despite the names, they are not identical to GNU coreutils’
version sort ordering).
* Using Debian’s sorting algorithm in:
+ python: [98]Stack Overflow Example #4957741.
+ NodeJS: [99]deb-version-compare.
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Previous: [100]Other version/natural sort implementations, Up:
[101]Advanced Topics
1.4.4 Related Source code
* Debian’s code which splits a version string into
epoch/upstream_version/debian_revision parts:
[102]parsehelp.c:parseversion().
* Debian’s code which performs the upstream_version comparison:
[103]version.c.
* GNULIB code (used by GNU coreutils) which performs the version
comparison: [104]filevercmp.c.
__________________________________________________________________
References
1. file:///tmp/tmpGWpjWH.html#Version-sort-ordering
2. file:///tmp/tmpGWpjWH.html#Version-sort-overview
3. file:///tmp/tmpGWpjWH.html#Implementation-Details
4. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
5. file:///tmp/tmpGWpjWH.html#Advanced-Topics
6. file:///tmp/tmpGWpjWH.html#Implementation-Details
7. file:///tmp/tmpGWpjWH.html#Version-sort-ordering
8. file:///tmp/tmpGWpjWH.html#Using-version-sort-in-GNU-coreutils
9.
file:///tmp/tmpGWpjWH.html#Origin-of-version-sort-and-differences-from-natural-sort
10.
file:///tmp/tmpGWpjWH.html#Correct_002fIncorrect-ordering-and-Expected_002fUnexpected-results
11.
file:///tmp/tmpGWpjWH.html#Origin-of-version-sort-and-differences-from-natural-sort
12. file:///tmp/tmpGWpjWH.html#Version-sort-overview
13.
file:///tmp/tmpGWpjWH.html#Correct_002fIncorrect-ordering-and-Expected_002fUnexpected-results
14. file:///tmp/tmpGWpjWH.html#Using-version-sort-in-GNU-coreutils
15. file:///tmp/tmpGWpjWH.html#Version-sort-overview
16. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
17. https://en.wikipedia.org/wiki/Natural_sort_order
18.
file:///tmp/tmpGWpjWH.html#Origin-of-version-sort-and-differences-from-natural-sort
19. file:///tmp/tmpGWpjWH.html#Version-sort-overview
20. file:///tmp/tmpGWpjWH.html#Other-version_002fnatural-sort-implementations
21. file:///tmp/tmpGWpjWH.html#Reporting-bugs-or-incorrect-results
22. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
23. file:///tmp/tmpGWpjWH.html#Version-sort-overview
24. file:///tmp/tmpGWpjWH.html#Version-sort-ordering
25. https://www.debian.org/doc/debian-policy/ch-controlfields.html#version
26. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
27. file:///tmp/tmpGWpjWH.html#Version_002dsort-ordering-rules
28. file:///tmp/tmpGWpjWH.html#Version-sort-is-not-the-same-as-numeric-sort
29. file:///tmp/tmpGWpjWH.html#Punctuation-Characters
30. file:///tmp/tmpGWpjWH.html#Punctuation-Characters-vs-letters
31. file:///tmp/tmpGWpjWH.html#Tilde-_007e-character
32. file:///tmp/tmpGWpjWH.html#Version-sort-ignores-locale
33. file:///tmp/tmpGWpjWH.html#Version-sort-is-not-the-same-as-numeric-sort
34. file:///tmp/tmpGWpjWH.html#Implementation-Details
35. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
36. file:///tmp/tmpGWpjWH.html#Punctuation-Characters
37. file:///tmp/tmpGWpjWH.html#Version_002dsort-ordering-rules
38. file:///tmp/tmpGWpjWH.html#Implementation-Details
39. file:///tmp/tmpGWpjWH.html#Punctuation-Characters-vs-letters
40. file:///tmp/tmpGWpjWH.html#Version-sort-is-not-the-same-as-numeric-sort
41. file:///tmp/tmpGWpjWH.html#Implementation-Details
42. file:///tmp/tmpGWpjWH.html#Version_002dsort-ordering-rules
43. file:///tmp/tmpGWpjWH.html#Tilde-_007e-character
44. file:///tmp/tmpGWpjWH.html#Punctuation-Characters
45. file:///tmp/tmpGWpjWH.html#Implementation-Details
46. file:///tmp/tmpGWpjWH.html#Version-sort-ignores-locale
47. file:///tmp/tmpGWpjWH.html#Punctuation-Characters-vs-letters
48. file:///tmp/tmpGWpjWH.html#Implementation-Details
49. file:///tmp/tmpGWpjWH.html#Tilde-_007e-character
50. file:///tmp/tmpGWpjWH.html#Implementation-Details
51. file:///tmp/tmpGWpjWH.html#Advanced-Topics
52. file:///tmp/tmpGWpjWH.html#Implementation-Details
53. file:///tmp/tmpGWpjWH.html#Version-sort-ordering
54.
file:///tmp/tmpGWpjWH.html#Minus_002fHyphen-_002d-and-Colon-_003a-characters
55.
file:///tmp/tmpGWpjWH.html#Additional-hard_002dcoded-priorities-in-GNU-coreutils_0027-version-sort
56. file:///tmp/tmpGWpjWH.html#Special-handling-of-file-extensions
57.
file:///tmp/tmpGWpjWH.html#Additional-hard_002dcoded-priorities-in-GNU-coreutils_0027-version-sort
58. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
59. https://bugs.gnu.org/35939
60. file:///tmp/tmpGWpjWH.html#Special-handling-of-file-extensions
61.
file:///tmp/tmpGWpjWH.html#Minus_002fHyphen-_002d-and-Colon-_003a-characters
62. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
63.
file:///tmp/tmpGWpjWH.html#Additional-hard_002dcoded-priorities-in-GNU-coreutils_0027-version-sort
64. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
65. file:///tmp/tmpGWpjWH.html#Version_002dsort-ordering-rules
66. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
67. file:///tmp/tmpGWpjWH.html#Version-sort-ordering
68.
file:///tmp/tmpGWpjWH.html#Comparing-two-strings-using-Debian_0027s-algorithm
69. file:///tmp/tmpGWpjWH.html#Reporting-bugs-or-incorrect-results
70. file:///tmp/tmpGWpjWH.html#Other-version_002fnatural-sort-implementations
71. file:///tmp/tmpGWpjWH.html#Related-Source-code
72. file:///tmp/tmpGWpjWH.html#Reporting-bugs-or-incorrect-results
73. file:///tmp/tmpGWpjWH.html#Advanced-Topics
74.
file:///tmp/tmpGWpjWH.html#Minus_002fHyphen-_002d-and-Colon-_003a-characters
75. file:///tmp/tmpGWpjWH.html#Special-handling-of-file-extensions
76. file:///tmp/tmpGWpjWH.html#Other-version_002fnatural-sort-implementations
77.
file:///tmp/tmpGWpjWH.html#Comparing-two-strings-using-Debian_0027s-algorithm
78. file:///tmp/tmpGWpjWH.html#Advanced-Topics
79.
file:///tmp/tmpGWpjWH.html#Comparing-two-strings-using-Debian_0027s-algorithm
80. file:///tmp/tmpGWpjWH.html#Differences-from-the-official-Debian-Algorithm
81. mailto:[email protected]
82. mailto:[email protected]
83. file:///tmp/tmpGWpjWH.html#Related-Source-code
84. file:///tmp/tmpGWpjWH.html#Reporting-bugs-or-incorrect-results
85. file:///tmp/tmpGWpjWH.html#Advanced-Topics
86. https://rosettacode.org/wiki/Natural_sorting
87. https://pypi.org/project/natsort/
88. https://natsort.readthedocs.io/en/master/howitworks.html
89. https://github.com/github/version_sorter
90. https://metacpan.org/pod/Sort::Naturally
91. https://metacpan.org/pod/Sort::Versions
92. https://metacpan.org/pod/CPAN::Version
93. https://www.php.net/manual/en/function.natsort.php
94. https://www.npmjs.com/package/natural-sort
95. http://zsh.sourceforge.net/Doc/Release/Expansion.html#Glob-Qualifiers
96. http://man7.org/linux/man-pages/man3/strverscmp.3.html
97. http://man7.org/linux/man-pages/man3/versionsort.3.html
98. https://stackoverflow.com/a/4957741
99. https://www.npmjs.com/package/deb-version-compare
100. file:///tmp/tmpGWpjWH.html#Other-version_002fnatural-sort-implementations
101. file:///tmp/tmpGWpjWH.html#Advanced-Topics
102. https://git.dpkg.org/cgit/dpkg/dpkg.git/tree/lib/dpkg/parsehelp.c#n191
103. https://git.dpkg.org/cgit/dpkg/dpkg.git/tree/lib/dpkg/version.c#n140
104. https://git.savannah.gnu.org/cgit/gnulib.git/tree/lib/filevercmp.c
