How does `diff` decide whether a difference is change (i.e. replacement) or combination of addition and deletion?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
-3
down vote

favorite












I was wondering how diff decides whether a difference is change (i.e. replacement) or combination of addition and deletion?



The best I can find from diffutils' manual is




‘fct’



Replace the lines in range f of the first file with lines in range t
of the second file. This is like a combined add and delete, but more
compact. For example, ‘5,7c8,10’ means change lines 5–7 of file 1 to
read as lines 8–10 of file 2; or,if changing file 2 into file 1,
change lines 8–10 of file 2 to read as lines 5–7 of file
1.




For example, I have two files, each having four lines



$ paste f2 f3
0 1
1 2
3 3
5 6


and I diff them



$ diff f2 f3
1d0
< 0
2a2
> 2
4c4
< 5
---
> 6


Why is 



1d0
< 0
2a2
> 2


not 



1,2c1,2
< 0
< 1
---
> 1
> 2


instead?



The alternative I gave and the diff output both have 3 as the common line, but my alternative treats the different lines before the common line as c i.e. replacement, while the diff output treats them as a combination of deletion and addition.






text-processing diff







share|improve this question























  • If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
    – don_crissti
    4 hours ago










  • Thanks. Can you be more specific when it comes to my questions?
    – Tim
    4 hours ago










  • No. I think the manual is very clear, just read the hunks subsection that I linked to...
    – don_crissti
    4 hours ago











  • I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
    – Tim
    4 hours ago











  • Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
    – don_crissti
    4 hours ago














up vote
-3
down vote

favorite












I was wondering how diff decides whether a difference is change (i.e. replacement) or combination of addition and deletion?



The best I can find from diffutils' manual is




‘fct’



Replace the lines in range f of the first file with lines in range t
of the second file. This is like a combined add and delete, but more
compact. For example, ‘5,7c8,10’ means change lines 5–7 of file 1 to
read as lines 8–10 of file 2; or,if changing file 2 into file 1,
change lines 8–10 of file 2 to read as lines 5–7 of file
1.




For example, I have two files, each having four lines



$ paste f2 f3
0 1
1 2
3 3
5 6


and I diff them



$ diff f2 f3
1d0
< 0
2a2
> 2
4c4
< 5
---
> 6


Why is 



1d0
< 0
2a2
> 2


not 



1,2c1,2
< 0
< 1
---
> 1
> 2


instead?



The alternative I gave and the diff output both have 3 as the common line, but my alternative treats the different lines before the common line as c i.e. replacement, while the diff output treats them as a combination of deletion and addition.






text-processing diff







share|improve this question























  • If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
    – don_crissti
    4 hours ago










  • Thanks. Can you be more specific when it comes to my questions?
    – Tim
    4 hours ago










  • No. I think the manual is very clear, just read the hunks subsection that I linked to...
    – don_crissti
    4 hours ago











  • I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
    – Tim
    4 hours ago











  • Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
    – don_crissti
    4 hours ago












up vote
-3
down vote

favorite









up vote
-3
down vote

favorite











I was wondering how diff decides whether a difference is change (i.e. replacement) or combination of addition and deletion?



The best I can find from diffutils' manual is




‘fct’



Replace the lines in range f of the first file with lines in range t
of the second file. This is like a combined add and delete, but more
compact. For example, ‘5,7c8,10’ means change lines 5–7 of file 1 to
read as lines 8–10 of file 2; or,if changing file 2 into file 1,
change lines 8–10 of file 2 to read as lines 5–7 of file
1.




For example, I have two files, each having four lines



$ paste f2 f3
0 1
1 2
3 3
5 6


and I diff them



$ diff f2 f3
1d0
< 0
2a2
> 2
4c4
< 5
---
> 6


Why is 



1d0
< 0
2a2
> 2


not 



1,2c1,2
< 0
< 1
---
> 1
> 2


instead?



The alternative I gave and the diff output both have 3 as the common line, but my alternative treats the different lines before the common line as c i.e. replacement, while the diff output treats them as a combination of deletion and addition.






text-processing diff







share|improve this question















I was wondering how diff decides whether a difference is change (i.e. replacement) or combination of addition and deletion?



The best I can find from diffutils' manual is




‘fct’



Replace the lines in range f of the first file with lines in range t
of the second file. This is like a combined add and delete, but more
compact. For example, ‘5,7c8,10’ means change lines 5–7 of file 1 to
read as lines 8–10 of file 2; or,if changing file 2 into file 1,
change lines 8–10 of file 2 to read as lines 5–7 of file
1.




For example, I have two files, each having four lines



$ paste f2 f3
0 1
1 2
3 3
5 6


and I diff them



$ diff f2 f3
1d0
< 0
2a2
> 2
4c4
< 5
---
> 6


Why is 



1d0
< 0
2a2
> 2


not 



1,2c1,2
< 0
< 1
---
> 1
> 2


instead?



The alternative I gave and the diff output both have 3 as the common line, but my alternative treats the different lines before the common line as c i.e. replacement, while the diff output treats them as a combination of deletion and addition.






text-processing diff




text-processing diff






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 3 hours ago

























asked 4 hours ago









Tim

24.7k70239431




24.7k70239431











  • If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
    – don_crissti
    4 hours ago










  • Thanks. Can you be more specific when it comes to my questions?
    – Tim
    4 hours ago










  • No. I think the manual is very clear, just read the hunks subsection that I linked to...
    – don_crissti
    4 hours ago











  • I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
    – Tim
    4 hours ago











  • Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
    – don_crissti
    4 hours ago
















  • If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
    – don_crissti
    4 hours ago










  • Thanks. Can you be more specific when it comes to my questions?
    – Tim
    4 hours ago










  • No. I think the manual is very clear, just read the hunks subsection that I linked to...
    – don_crissti
    4 hours ago











  • I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
    – Tim
    4 hours ago











  • Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
    – don_crissti
    4 hours ago















If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
– don_crissti
4 hours ago




If you read the manual, it says diff tries to minimize the total hunk size by finding large sequences of common lines interspersed with small hunks of differing lines... there are even examples etc...
– don_crissti
4 hours ago












Thanks. Can you be more specific when it comes to my questions?
– Tim
4 hours ago




Thanks. Can you be more specific when it comes to my questions?
– Tim
4 hours ago












No. I think the manual is very clear, just read the hunks subsection that I linked to...
– don_crissti
4 hours ago





No. I think the manual is very clear, just read the hunks subsection that I linked to...
– don_crissti
4 hours ago













I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
– Tim
4 hours ago





I have. But I can't relate it here. I was wondering whether I am missing something, or you actually miss my question?
– Tim
4 hours ago













Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
– don_crissti
4 hours ago




Well, I cannot understand most of your questions but this one is pretty clear... And so is the answer in the manual: In general, there are many ways to match up lines between two given files.
– don_crissti
4 hours ago















active

oldest

votes











Your Answer








StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "106"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













 

draft saved


draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f480848%2fhow-does-diff-decide-whether-a-difference-is-change-i-e-replacement-or-comb%23new-answer', 'question_page');

);

Post as a guest






















active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes















 

draft saved


draft discarded















































 


draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f480848%2fhow-does-diff-decide-whether-a-difference-is-change-i-e-replacement-or-comb%23new-answer', 'question_page');

);

Post as a guest
































































-

Popular posts from this blog

How to check contact read email or not when send email to Individual?

Image
Clash Royale CLAN TAG #URR8PPP up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this question asked Sep 26 at 0:12 ToanLuong 49 9 add a comment  |  up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this question asked Se
Read more

Displaying single band from multi-band raster using QGIS

Image
Clash Royale CLAN TAG #URR8PPP 1 How can I extract a single band from multi-band raster in QGIS? I have an remote sensed image which has 6 bands (including NDVI band), I want to display each band separately, but have no idea how to do. I have seen some questions similar here but none worked for me. The original image (has 6 bands) is: I want to display the band 6 which should be like this: But I tried gdal_translate, and couldn't get the correct result. What I have got is: qgis raster multi-band share | improve this question edited Mar 5 at 0:53 Summer asked Mar 4 at 6:42 Summer Summer 23 6 Is this any help gis.stackexchange.com/questions/220658/… ? if not gis.stackexchange.com/questions/62133/… might help. – Michael Stimson Mar 4 at 6:46 Thanks for answering but when I used gdal_translate, qgis showed that 'Error 4: Kayena.tif: No such file or directory". Would you know how to fix it? –
Read more

How many registers does an x86_64 CPU actually have?

Image
Clash Royale CLAN TAG #URR8PPP up vote 2 down vote favorite I am currently learning reverse engineering and am studying the flags register. I had in my mind that rflags was just another name for one of the 16 general purpose registers, for example rax or rbx . But it looks like rflags is actually an additional register. So that makes 17 registers in total... how many more could there be? I have spent at least an hour on this and found numerous different answers. The best answer so far is this, which says that there are 40 registers in total. 16 General Purpose Registers 2 Status Registers 6 Code Segment Registers 16 SSE Registers 8 FPU/MMX Registers But if I add that up, I get 48. Could anybody provide an official answer on how many registers an x86_64 CPU has (e.g. an Intel i7). Additionally, I have seen references to 'hardware' and 'architectural' registers. What are those registers and how many are there? register x86-64 share | improve this
Read more