How to collapse consecutive numbers into ranges?

up vote
4
down vote

favorite

Given a sorted input file (or command output) that contains unique numbers, one per line, I would like to collapse all runs of consecutive numbers into ranges such that

n
n+1
...
n+m

becomes

n,n+m

input sample:

expected output:

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

Very nice question, but would benefit from some clarifications for newbies. Please !
â€“Â TNT
7 hours ago

@TNT - let me know which part is unclear
â€“Â don_crissti
6 hours ago

thank you. just not clear to me what it means n then n+1. given first number is 2 then I assume first range 2,3 then second range should be 9,10 then 10-11 how you calculated the "expected output" ranges. Would be appreciated if you explain.
â€“Â TNT
5 hours ago

@TNT - consecutive ="following each other continuously" (I'm 100% sure consecutive has the same meaning in all languages) so when I say collapse all consecutive numbers I mean all consecutive numbers like n, n+1, n+2, n+3 and so on (Ã la n++) up to n+m should be combined into a single range: n,n+m. So combine as many numbers as possible as long as they are consecutive.
â€“Â don_crissti
4 hours ago

add a commentÂ |Â

up vote
4
down vote

favorite

Given a sorted input file (or command output) that contains unique numbers, one per line, I would like to collapse all runs of consecutive numbers into ranges such that

n
n+1
...
n+m

becomes

n,n+m

input sample:

expected output:

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

Very nice question, but would benefit from some clarifications for newbies. Please !
â€“Â TNT
7 hours ago

@TNT - let me know which part is unclear
â€“Â don_crissti
6 hours ago

thank you. just not clear to me what it means n then n+1. given first number is 2 then I assume first range 2,3 then second range should be 9,10 then 10-11 how you calculated the "expected output" ranges. Would be appreciated if you explain.
â€“Â TNT
5 hours ago

@TNT - consecutive ="following each other continuously" (I'm 100% sure consecutive has the same meaning in all languages) so when I say collapse all consecutive numbers I mean all consecutive numbers like n, n+1, n+2, n+3 and so on (Ã la n++) up to n+m should be combined into a single range: n,n+m. So combine as many numbers as possible as long as they are consecutive.
â€“Â don_crissti
4 hours ago

add a commentÂ |Â

up vote
4
down vote

favorite

Given a sorted input file (or command output) that contains unique numbers, one per line, I would like to collapse all runs of consecutive numbers into ranges such that

n
n+1
...
n+m

becomes

n,n+m

input sample:

expected output:

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

Given a sorted input file (or command output) that contains unique numbers, one per line, I would like to collapse all runs of consecutive numbers into ranges such that

n
n+1
...
n+m

becomes

n,n+m

input sample:

expected output:

text-processing numeric-data

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

edited 7 hours ago

Jeff Schaller

32.6k849110

edited 7 hours ago

Jeff Schaller

32.6k849110

edited 7 hours ago

Jeff Schaller

32.6k849110

asked 7 hours ago

don_crissti

47.2k15125155

asked 7 hours ago

don_crissti

47.2k15125155

asked 7 hours ago

don_crissti

47.2k15125155

Very nice question, but would benefit from some clarifications for newbies. Please !
â€“Â TNT
7 hours ago

@TNT - let me know which part is unclear
â€“Â don_crissti
6 hours ago

thank you. just not clear to me what it means n then n+1. given first number is 2 then I assume first range 2,3 then second range should be 9,10 then 10-11 how you calculated the "expected output" ranges. Would be appreciated if you explain.
â€“Â TNT
5 hours ago

@TNT - consecutive ="following each other continuously" (I'm 100% sure consecutive has the same meaning in all languages) so when I say collapse all consecutive numbers I mean all consecutive numbers like n, n+1, n+2, n+3 and so on (Ã la n++) up to n+m should be combined into a single range: n,n+m. So combine as many numbers as possible as long as they are consecutive.
â€“Â don_crissti
4 hours ago

add a commentÂ |Â

Very nice question, but would benefit from some clarifications for newbies. Please !
â€“Â TNT
7 hours ago

@TNT - let me know which part is unclear
â€“Â don_crissti
6 hours ago

thank you. just not clear to me what it means n then n+1. given first number is 2 then I assume first range 2,3 then second range should be 9,10 then 10-11 how you calculated the "expected output" ranges. Would be appreciated if you explain.
â€“Â TNT
5 hours ago

@TNT - consecutive ="following each other continuously" (I'm 100% sure consecutive has the same meaning in all languages) so when I say collapse all consecutive numbers I mean all consecutive numbers like n, n+1, n+2, n+3 and so on (Ã la n++) up to n+m should be combined into a single range: n,n+m. So combine as many numbers as possible as long as they are consecutive.
â€“Â don_crissti
4 hours ago

Very nice question, but would benefit from some clarifications for newbies. Please !
â€“Â TNT
7 hours ago

@TNT - let me know which part is unclear
â€“Â don_crissti
6 hours ago

thank you. just not clear to me what it means n then n+1. given first number is 2 then I assume first range 2,3 then second range should be 9,10 then 10-11 how you calculated the "expected output" ranges. Would be appreciated if you explain.
â€“Â TNT
5 hours ago

@TNT - consecutive ="following each other continuously" (I'm 100% sure consecutive has the same meaning in all languages) so when I say collapse all consecutive numbers I mean all consecutive numbers like n, n+1, n+2, n+3 and so on (Ã la n++) up to n+m should be combined into a single range: n,n+m. So combine as many numbers as possible as long as they are consecutive.
â€“Â don_crissti
4 hours ago

add a commentÂ |Â

4 Answers
4

active

oldest

votes

up vote
4
down vote

awk '
 function output() print start (prev == start ? "" : ","prev) 
 NR == 1 start = prev = $1; next
 $1 > prev+1 output(); start = $1
 prev = $1
 END output()
'

answered 7 hours ago

glenn jackman

47.6k265104

add a commentÂ |Â

up vote
2
down vote

Perl approach!

#!/bin/perl
 print ranges(2,3,9,10,11,12,24,28,29,33), "n";

sub ranges 
 my @vals = @_;
 my $first = $vals[0];
 my $last;
 my @list;
 for my $i (0 .. (scalar(@vals)-2)) 
 if (($vals[$i+1] - $vals[$i]) != 1) 
 $last = $vals[$i];
 push @list, ($first == $last) ? $first : "$first,$last";
 $first = $vals[$i+1];
 
 
 $last = $vals[-1];
 push @list, ($first == $last) ? $first : "$first,$last";
 return join ("n", @list);

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

2

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

add a commentÂ |Â

up vote
1
down vote

How about

awk '
$0 > LAST+1 if (NR > 1) print (PR != LAST)?"," LAST:""
 printf "%s", $0
 PR = $0
 
 LAST = $0
 
END print (PR != LAST)?"," LAST:""
 
' file
2,3
9,12
24
28,29
33

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

add a commentÂ |Â

up vote
1
down vote

awk, with a different (more C-like) approach:

awk ' do for(s=e=$1; (r=getline)>0 && $1<=e+1; e=$1); print s==e ? s : s","e while(r>0) ' file

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

add a commentÂ |Â

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4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

up vote
4
down vote

awk '
 function output() print start (prev == start ? "" : ","prev) 
 NR == 1 start = prev = $1; next
 $1 > prev+1 output(); start = $1
 prev = $1
 END output()
'

answered 7 hours ago

glenn jackman

47.6k265104

add a commentÂ |Â

up vote
4
down vote

awk '
 function output() print start (prev == start ? "" : ","prev) 
 NR == 1 start = prev = $1; next
 $1 > prev+1 output(); start = $1
 prev = $1
 END output()
'

answered 7 hours ago

glenn jackman

47.6k265104

add a commentÂ |Â

up vote
4
down vote

awk '
 function output() print start (prev == start ? "" : ","prev) 
 NR == 1 start = prev = $1; next
 $1 > prev+1 output(); start = $1
 prev = $1
 END output()
'

answered 7 hours ago

glenn jackman

47.6k265104

awk '
 function output() print start (prev == start ? "" : ","prev) 
 NR == 1 start = prev = $1; next
 $1 > prev+1 output(); start = $1
 prev = $1
 END output()
'

answered 7 hours ago

glenn jackman

47.6k265104

answered 7 hours ago

glenn jackman

47.6k265104

answered 7 hours ago

glenn jackman

47.6k265104

answered 7 hours ago

glenn jackman

47.6k265104

add a commentÂ |Â

up vote
2
down vote

Perl approach!

#!/bin/perl
 print ranges(2,3,9,10,11,12,24,28,29,33), "n";

sub ranges 
 my @vals = @_;
 my $first = $vals[0];
 my $last;
 my @list;
 for my $i (0 .. (scalar(@vals)-2)) 
 if (($vals[$i+1] - $vals[$i]) != 1) 
 $last = $vals[$i];
 push @list, ($first == $last) ? $first : "$first,$last";
 $first = $vals[$i+1];
 
 
 $last = $vals[-1];
 push @list, ($first == $last) ? $first : "$first,$last";
 return join ("n", @list);

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

2

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

add a commentÂ |Â

up vote
2
down vote

Perl approach!

#!/bin/perl
 print ranges(2,3,9,10,11,12,24,28,29,33), "n";

sub ranges 
 my @vals = @_;
 my $first = $vals[0];
 my $last;
 my @list;
 for my $i (0 .. (scalar(@vals)-2)) 
 if (($vals[$i+1] - $vals[$i]) != 1) 
 $last = $vals[$i];
 push @list, ($first == $last) ? $first : "$first,$last";
 $first = $vals[$i+1];
 
 
 $last = $vals[-1];
 push @list, ($first == $last) ? $first : "$first,$last";
 return join ("n", @list);

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

2

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

add a commentÂ |Â

up vote
2
down vote

Perl approach!

#!/bin/perl
 print ranges(2,3,9,10,11,12,24,28,29,33), "n";

sub ranges 
 my @vals = @_;
 my $first = $vals[0];
 my $last;
 my @list;
 for my $i (0 .. (scalar(@vals)-2)) 
 if (($vals[$i+1] - $vals[$i]) != 1) 
 $last = $vals[$i];
 push @list, ($first == $last) ? $first : "$first,$last";
 $first = $vals[$i+1];
 
 
 $last = $vals[-1];
 push @list, ($first == $last) ? $first : "$first,$last";
 return join ("n", @list);

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

Perl approach!

#!/bin/perl
 print ranges(2,3,9,10,11,12,24,28,29,33), "n";

sub ranges 
 my @vals = @_;
 my $first = $vals[0];
 my $last;
 my @list;
 for my $i (0 .. (scalar(@vals)-2)) 
 if (($vals[$i+1] - $vals[$i]) != 1) 
 $last = $vals[$i];
 push @list, ($first == $last) ? $first : "$first,$last";
 $first = $vals[$i+1];
 
 
 $last = $vals[-1];
 push @list, ($first == $last) ? $first : "$first,$last";
 return join ("n", @list);

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

edited 4 hours ago

answered 7 hours ago

Goro

3,05441951

answered 7 hours ago

Goro

3,05441951

answered 7 hours ago

Goro

3,05441951

2

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

add a commentÂ |Â

2

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

24,24 and 33,33 is not quite what was requested...
â€“Â RudiC
6 hours ago

As your awk approach is quite similar to glenn jackman's and mine, refer to those.
â€“Â RudiC
4 hours ago

add a commentÂ |Â

up vote
1
down vote

How about

awk '
$0 > LAST+1 if (NR > 1) print (PR != LAST)?"," LAST:""
 printf "%s", $0
 PR = $0
 
 LAST = $0
 
END print (PR != LAST)?"," LAST:""
 
' file
2,3
9,12
24
28,29
33

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

add a commentÂ |Â

up vote
1
down vote

How about

awk '
$0 > LAST+1 if (NR > 1) print (PR != LAST)?"," LAST:""
 printf "%s", $0
 PR = $0
 
 LAST = $0
 
END print (PR != LAST)?"," LAST:""
 
' file
2,3
9,12
24
28,29
33

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

add a commentÂ |Â

up vote
1
down vote

How about

awk '
$0 > LAST+1 if (NR > 1) print (PR != LAST)?"," LAST:""
 printf "%s", $0
 PR = $0
 
 LAST = $0
 
END print (PR != LAST)?"," LAST:""
 
' file
2,3
9,12
24
28,29
33

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

How about

awk '
$0 > LAST+1 if (NR > 1) print (PR != LAST)?"," LAST:""
 printf "%s", $0
 PR = $0
 
 LAST = $0
 
END print (PR != LAST)?"," LAST:""
 
' file
2,3
9,12
24
28,29
33

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

edited 7 hours ago

answered 7 hours ago

RudiC

1,2167

answered 7 hours ago

RudiC

1,2167

answered 7 hours ago

RudiC

1,2167

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

add a commentÂ |Â

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

I'd stick to lower case variable names, but that's just style. I came up with the same logic.
â€“Â glenn jackman
7 hours ago

Actually, there is a bug here: if the first line is less than one, the first condition will be false, so the the first number will not be printed. You need a separate rule for NR==1
â€“Â glenn jackman
7 hours ago

I might recheck. I'm not too happy with the clumsy logics anyhow.
â€“Â RudiC
7 hours ago

add a commentÂ |Â

up vote
1
down vote

awk, with a different (more C-like) approach:

awk ' do for(s=e=$1; (r=getline)>0 && $1<=e+1; e=$1); print s==e ? s : s","e while(r>0) ' file

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

add a commentÂ |Â

up vote
1
down vote

awk, with a different (more C-like) approach:

awk ' do for(s=e=$1; (r=getline)>0 && $1<=e+1; e=$1); print s==e ? s : s","e while(r>0) ' file

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

add a commentÂ |Â

up vote
1
down vote

awk, with a different (more C-like) approach:

awk ' do for(s=e=$1; (r=getline)>0 && $1<=e+1; e=$1); print s==e ? s : s","e while(r>0) ' file

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

awk, with a different (more C-like) approach:

awk ' do for(s=e=$1; (r=getline)>0 && $1<=e+1; e=$1); print s==e ? s : s","e while(r>0) ' file

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

edited 6 hours ago

don_crissti

47.2k15125155

edited 6 hours ago

don_crissti

47.2k15125155

edited 6 hours ago

don_crissti

47.2k15125155

answered 6 hours ago

mosvy

7176

answered 6 hours ago

mosvy

7176

answered 6 hours ago

mosvy

7176

add a commentÂ |Â

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