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.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}

5

Suppose I have 6 lines of text.

Series

Of

Word

73914

Again

Word

I need to prepend a string to the beginning of lines that contain ONLY numbers. Say I insert number-

Series

Of

Word

number-73914

Again

Word

Currently I run two commands to achieve the desired result. I wonder if there is a more efficient method.

Note: There are 1000+ lines, so preferably this applies to all lines ( I already state it ).

command-line text-processing sed awk

share|improve this question

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  What do you want to do with a line like 1st word 2nd word?
  
  – glenn jackman
  Mar 29 at 18:00
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  And do you want only lines that are entirely a number or that start with a number? E.g. would you want 123abc to be changed to number-123abc or not?
  
  – Kevin
  Mar 29 at 19:57
  
  
  

  
  
  
  

add a comment | 

5

Suppose I have 6 lines of text.

Series

Of

Word

73914

Again

Word

I need to prepend a string to the beginning of lines that contain ONLY numbers. Say I insert number-

Series

Of

Word

number-73914

Again

Word

Currently I run two commands to achieve the desired result. I wonder if there is a more efficient method.

Note: There are 1000+ lines, so preferably this applies to all lines ( I already state it ).

command-line text-processing sed awk

share|improve this question

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  What do you want to do with a line like 1st word 2nd word?
  
  – glenn jackman
  Mar 29 at 18:00
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  And do you want only lines that are entirely a number or that start with a number? E.g. would you want 123abc to be changed to number-123abc or not?
  
  – Kevin
  Mar 29 at 19:57
  
  
  

  
  
  
  

add a comment | 

Suppose I have 6 lines of text.

Series

Of

Word

73914

Again

Word

I need to prepend a string to the beginning of lines that contain ONLY numbers. Say I insert number-

Series

Of

Word

number-73914

Again

Word

Currently I run two commands to achieve the desired result. I wonder if there is a more efficient method.

Note: There are 1000+ lines, so preferably this applies to all lines ( I already state it ).

command-line text-processing sed awk

share|improve this question

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

Series

Of

Word

73914

Again

Word

Series

Of

Word

number-73914

Again

Word

share|improve this question

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

share|improve this question

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

edited Mar 29 at 9:21

Martin Thornton

2,56361830

edited Mar 29 at 9:21

Martin Thornton

2,56361830

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

asked Mar 29 at 3:24

EmmetEmmet

7,51522345

4 Answers
4

active

oldest

votes

9

sed can do that:

$ sed 's/^[[:digit:]]*$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

In case we want to account for empty lines, we'd use + and -r option:

$ sed -r 's/^[[:digit:]]+$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

Once you verify everything is proper, you can use -i option to edit the file itself, i.e. sed -i .... Otherwise, you can always make a copy of the file with sed 's/^[[:digit:]]*$/number-&/' input.txt > output.txt

Note that this assumes consistent file format, with no leading whitespaces or trailing whitespaces on each line.

And here's Python as extra:

$ python3 -c 'import sys; print("n".join([ "number-" + i.strip() if i.strip().isnumeric() else i.strip() for i in sys.stdin]))' < input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

share|improve this answer

edited Mar 29 at 7:07

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I often use the "substitute if match" variant for things like this /^[[:digit:]]+$/ s/^/number-/'
  
  – steeldriver
  Mar 29 at 7:29
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the complete instruction, I'm a total noob when it comes to text processing :-O
  
  – Emmet
  Mar 29 at 9:41
  

  
  
  
  

add a comment | 

4

One way using awk:

awk '/^[0-9]+$/{$0="number-"$0;}1'  file

share|improve this answer

answered Mar 29 at 7:04

GuruGuru

52838

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I also seek awk solution, thanks ! 1+
  
  – Emmet
  Mar 29 at 9:42
  

  
  
  
  

add a comment | 

3

lines that contain ONLY numbers

It's unclear whether you mean numbers or just 0-9. Here's a Perl one-liner that picks out the likes of 123, 3.14 and 1e-12 while ignoring various representations of infinity and not-a-number:

$ perl -MScalar::Util -ne 'chomp; if (!(m/^s/ || m/^[+-]?inf(?:inity)?$/i || m/^nan$/i) && Scalar::Util::looks_like_number($_)) { print("N:"); } print("$_n");' <x

a

N:123

N:+1

N:-1

 1

b



1a

N:3.14

c

3.1415926 is an approximation of pi

N:1e-12

inf

Inf

Infinity

Infinity +1 sword

+Infinity

-infinity

NaN

1/2

I changed the prefix to "N:" simply because "number--1" looks a bit rubbish. Note that this treats " 1", for example, as not numeric. If that is undesirable behaviour, do not include the "m/^s/" test for leading whitespace.

If you mean "0-9", Sergiy's sed solution above is fine.

share|improve this answer

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Probably an overkill for this question, but still awesome ! +1
  
  – Sergiy Kolodyazhnyy
  Mar 29 at 12:06
  

  
  
  
  

add a comment | 

2

You can try this

$cat input.txt

Series

Of

Word

73914

Again

Word



$awk '{ if($1 ~/[0-9]/) printf "number - %sn",$1; else print $1 }' input.txt

Series

Of

Word

number - 73914

Again

Word

share|improve this answer

answered Mar 29 at 7:26

GoronGoron

1669

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Using if statement, nice ! Thank you :D
  
  – Emmet
  Mar 29 at 9:42
  
  
  

  
  
  
  

add a comment | 

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9

sed can do that:

$ sed 's/^[[:digit:]]*$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

In case we want to account for empty lines, we'd use + and -r option:

$ sed -r 's/^[[:digit:]]+$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

Once you verify everything is proper, you can use -i option to edit the file itself, i.e. sed -i .... Otherwise, you can always make a copy of the file with sed 's/^[[:digit:]]*$/number-&/' input.txt > output.txt

Note that this assumes consistent file format, with no leading whitespaces or trailing whitespaces on each line.

And here's Python as extra:

$ python3 -c 'import sys; print("n".join([ "number-" + i.strip() if i.strip().isnumeric() else i.strip() for i in sys.stdin]))' < input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

share|improve this answer

edited Mar 29 at 7:07

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I often use the "substitute if match" variant for things like this /^[[:digit:]]+$/ s/^/number-/'
  
  – steeldriver
  Mar 29 at 7:29
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the complete instruction, I'm a total noob when it comes to text processing :-O
  
  – Emmet
  Mar 29 at 9:41
  

  
  
  
  

add a comment | 

9

sed can do that:

$ sed 's/^[[:digit:]]*$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

In case we want to account for empty lines, we'd use + and -r option:

$ sed -r 's/^[[:digit:]]+$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

Once you verify everything is proper, you can use -i option to edit the file itself, i.e. sed -i .... Otherwise, you can always make a copy of the file with sed 's/^[[:digit:]]*$/number-&/' input.txt > output.txt

Note that this assumes consistent file format, with no leading whitespaces or trailing whitespaces on each line.

And here's Python as extra:

$ python3 -c 'import sys; print("n".join([ "number-" + i.strip() if i.strip().isnumeric() else i.strip() for i in sys.stdin]))' < input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

share|improve this answer

edited Mar 29 at 7:07

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I often use the "substitute if match" variant for things like this /^[[:digit:]]+$/ s/^/number-/'
  
  – steeldriver
  Mar 29 at 7:29
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the complete instruction, I'm a total noob when it comes to text processing :-O
  
  – Emmet
  Mar 29 at 9:41
  

  
  
  
  

add a comment | 

sed can do that:

$ sed 's/^[[:digit:]]*$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

In case we want to account for empty lines, we'd use + and -r option:

$ sed -r 's/^[[:digit:]]+$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

Once you verify everything is proper, you can use -i option to edit the file itself, i.e. sed -i .... Otherwise, you can always make a copy of the file with sed 's/^[[:digit:]]*$/number-&/' input.txt > output.txt

Note that this assumes consistent file format, with no leading whitespaces or trailing whitespaces on each line.

And here's Python as extra:

$ python3 -c 'import sys; print("n".join([ "number-" + i.strip() if i.strip().isnumeric() else i.strip() for i in sys.stdin]))' < input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

share|improve this answer

edited Mar 29 at 7:07

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

$ sed 's/^[[:digit:]]*$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

$ sed -r 's/^[[:digit:]]+$/number-&/' input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

$ python3 -c 'import sys; print("n".join([ "number-" + i.strip() if i.strip().isnumeric() else i.strip() for i in sys.stdin]))' < input.txt

Series

Of

Word

number-73914

Again

Word

line below is empty



line above is empty

share|improve this answer

edited Mar 29 at 7:07

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

answered Mar 29 at 7:00

Sergiy KolodyazhnyySergiy Kolodyazhnyy

75k9155327

4

One way using awk:

awk '/^[0-9]+$/{$0="number-"$0;}1'  file

share|improve this answer

answered Mar 29 at 7:04

GuruGuru

52838

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I also seek awk solution, thanks ! 1+
  
  – Emmet
  Mar 29 at 9:42
  

  
  
  
  

add a comment | 

4

One way using awk:

awk '/^[0-9]+$/{$0="number-"$0;}1'  file

share|improve this answer

answered Mar 29 at 7:04

GuruGuru

52838

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I also seek awk solution, thanks ! 1+
  
  – Emmet
  Mar 29 at 9:42
  

  
  
  
  

add a comment | 

One way using awk:

awk '/^[0-9]+$/{$0="number-"$0;}1'  file

share|improve this answer

answered Mar 29 at 7:04

GuruGuru

52838

awk '/^[0-9]+$/{$0="number-"$0;}1'  file

share|improve this answer

answered Mar 29 at 7:04

GuruGuru

52838

answered Mar 29 at 7:04

GuruGuru

52838

answered Mar 29 at 7:04

GuruGuru

52838

3

lines that contain ONLY numbers

It's unclear whether you mean numbers or just 0-9. Here's a Perl one-liner that picks out the likes of 123, 3.14 and 1e-12 while ignoring various representations of infinity and not-a-number:

$ perl -MScalar::Util -ne 'chomp; if (!(m/^s/ || m/^[+-]?inf(?:inity)?$/i || m/^nan$/i) && Scalar::Util::looks_like_number($_)) { print("N:"); } print("$_n");' <x

a

N:123

N:+1

N:-1

 1

b



1a

N:3.14

c

3.1415926 is an approximation of pi

N:1e-12

inf

Inf

Infinity

Infinity +1 sword

+Infinity

-infinity

NaN

1/2

I changed the prefix to "N:" simply because "number--1" looks a bit rubbish. Note that this treats " 1", for example, as not numeric. If that is undesirable behaviour, do not include the "m/^s/" test for leading whitespace.

If you mean "0-9", Sergiy's sed solution above is fine.

share|improve this answer

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Probably an overkill for this question, but still awesome ! +1
  
  – Sergiy Kolodyazhnyy
  Mar 29 at 12:06
  

  
  
  
  

add a comment | 

3

lines that contain ONLY numbers

It's unclear whether you mean numbers or just 0-9. Here's a Perl one-liner that picks out the likes of 123, 3.14 and 1e-12 while ignoring various representations of infinity and not-a-number:

$ perl -MScalar::Util -ne 'chomp; if (!(m/^s/ || m/^[+-]?inf(?:inity)?$/i || m/^nan$/i) && Scalar::Util::looks_like_number($_)) { print("N:"); } print("$_n");' <x

a

N:123

N:+1

N:-1

 1

b



1a

N:3.14

c

3.1415926 is an approximation of pi

N:1e-12

inf

Inf

Infinity

Infinity +1 sword

+Infinity

-infinity

NaN

1/2

I changed the prefix to "N:" simply because "number--1" looks a bit rubbish. Note that this treats " 1", for example, as not numeric. If that is undesirable behaviour, do not include the "m/^s/" test for leading whitespace.

If you mean "0-9", Sergiy's sed solution above is fine.

share|improve this answer

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Probably an overkill for this question, but still awesome ! +1
  
  – Sergiy Kolodyazhnyy
  Mar 29 at 12:06
  

  
  
  
  

add a comment | 

lines that contain ONLY numbers

It's unclear whether you mean numbers or just 0-9. Here's a Perl one-liner that picks out the likes of 123, 3.14 and 1e-12 while ignoring various representations of infinity and not-a-number:

$ perl -MScalar::Util -ne 'chomp; if (!(m/^s/ || m/^[+-]?inf(?:inity)?$/i || m/^nan$/i) && Scalar::Util::looks_like_number($_)) { print("N:"); } print("$_n");' <x

a

N:123

N:+1

N:-1

 1

b



1a

N:3.14

c

3.1415926 is an approximation of pi

N:1e-12

inf

Inf

Infinity

Infinity +1 sword

+Infinity

-infinity

NaN

1/2

I changed the prefix to "N:" simply because "number--1" looks a bit rubbish. Note that this treats " 1", for example, as not numeric. If that is undesirable behaviour, do not include the "m/^s/" test for leading whitespace.

If you mean "0-9", Sergiy's sed solution above is fine.

share|improve this answer

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

$ perl -MScalar::Util -ne 'chomp; if (!(m/^s/ || m/^[+-]?inf(?:inity)?$/i || m/^nan$/i) && Scalar::Util::looks_like_number($_)) { print("N:"); } print("$_n");' <x

a

N:123

N:+1

N:-1

 1

b



1a

N:3.14

c

3.1415926 is an approximation of pi

N:1e-12

inf

Inf

Infinity

Infinity +1 sword

+Infinity

-infinity

NaN

1/2

share|improve this answer

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

answered Mar 29 at 11:56

Chris WilliamsChris Williams

311

2

You can try this

$cat input.txt

Series

Of

Word

73914

Again

Word



$awk '{ if($1 ~/[0-9]/) printf "number - %sn",$1; else print $1 }' input.txt

Series

Of

Word

number - 73914

Again

Word

share|improve this answer

answered Mar 29 at 7:26

GoronGoron

1669

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Using if statement, nice ! Thank you :D
  
  – Emmet
  Mar 29 at 9:42
  
  
  

  
  
  
  

add a comment | 

2

You can try this

$cat input.txt

Series

Of

Word

73914

Again

Word



$awk '{ if($1 ~/[0-9]/) printf "number - %sn",$1; else print $1 }' input.txt

Series

Of

Word

number - 73914

Again

Word

share|improve this answer

answered Mar 29 at 7:26

GoronGoron

1669

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Using if statement, nice ! Thank you :D
  
  – Emmet
  Mar 29 at 9:42
  
  
  

  
  
  
  

add a comment | 

You can try this

$cat input.txt

Series

Of

Word

73914

Again

Word



$awk '{ if($1 ~/[0-9]/) printf "number - %sn",$1; else print $1 }' input.txt

Series

Of

Word

number - 73914

Again

Word

share|improve this answer

answered Mar 29 at 7:26

GoronGoron

1669

$cat input.txt

Series

Of

Word

73914

Again

Word



$awk '{ if($1 ~/[0-9]/) printf "number - %sn",$1; else print $1 }' input.txt

Series

Of

Word

number - 73914

Again

Word

share|improve this answer

answered Mar 29 at 7:26

GoronGoron

1669

answered Mar 29 at 7:26

GoronGoron

1669

answered Mar 29 at 7:26

GoronGoron

1669