Is it possible to have a wealthy country without a middle class?

What's up with this leaf?

How did old MS-DOS games utilize various graphic cards?

SQL counting distinct over partition

Does the Long March-11 increase its thrust after clearing the launch tower?

Did Milano or Benatar approve or comment on their namesake MCU ships?

Non-disclosure agreement in a small business

English word for "product of tinkering"

Is this use of the expression "long past" correct?

How to handle self harm scars on the arm in work environment?

Someone whose aspirations exceed abilities or means

Second (easy access) account in case my bank screws up

What speaks against investing in precious metals?

Union with anonymous struct with flexible array member

What can I, as a user, do about offensive reviews in App Store?

Are there any important biographies of nobodies?

Using "subway" as name for London Underground?

1980s live-action movie where individually-coloured nations on clouds fight

Need feedback - Can the composition/colors of this design be fixed if something is lacking or is not a better fit?

How can I get an unreasonable manager to approve time off?

How do I prevent employees from either switching to competitors or opening their own business?

Is it possible to have the age of the universe be unknown?

Is using haveibeenpwned to validate password strength rational?

is it possible for a vehicle to be manufactured witout a catalitic converter

How to split a string in two substrings of same length using bash?

How to split a string into an array in bashBash Combine Replacement and Sub String Extraction in One StepPiping bash string manipulationBash - Split quoted parametersSplit single string into character array using ONLY bashPrint month between two wordsSplit a string by some separator in bash?Cut the string in half with the last specific character shows up in the stringbash command to print string in unambiguous formsplit string to two parts using sed or awk or perl or bash

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

12

I would like to split a string into two halves and print them sequentially. For example:

abcdef

into

abc
def

Is there a simple way to do it, or it needs some string processing?

bash string

share|improve this question

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do you have the incoming string? Variable? Stdin? Other?
  
  – Jeff Schaller♦
  May 30 at 21:24
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  In a variable. It doesn't really matter, as anything can be worked out (stdin input can be put in a variable).
  
  – Gabriel Diego
  May 30 at 21:27
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  It matters for efficiency, especially if it can be possibly-gigantic. And also for convenience.
  
  – Peter Cordes
  May 31 at 10:36
  
  

  
  
  
  

add a comment | 

12

I would like to split a string into two halves and print them sequentially. For example:

abcdef

into

abc
def

Is there a simple way to do it, or it needs some string processing?

bash string

share|improve this question

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do you have the incoming string? Variable? Stdin? Other?
  
  – Jeff Schaller♦
  May 30 at 21:24
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  In a variable. It doesn't really matter, as anything can be worked out (stdin input can be put in a variable).
  
  – Gabriel Diego
  May 30 at 21:27
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  It matters for efficiency, especially if it can be possibly-gigantic. And also for convenience.
  
  – Peter Cordes
  May 31 at 10:36
  
  

  
  
  
  

add a comment | 

I would like to split a string into two halves and print them sequentially. For example:

abcdef

into

abc
def

Is there a simple way to do it, or it needs some string processing?

bash string

share|improve this question

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

abcdef

abc
def

share|improve this question

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

edited May 30 at 21:23

Jeff Schaller♦

46.4k1166150

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

New contributor

Gabriel Diego is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked May 30 at 21:11

Gabriel DiegoGabriel Diego

1665

4 Answers
4

active

oldest

votes

16

Using parameter expansion and shell arithmetic:

The first half of the variable will be:

$var:0:$#var/2

The second half of the variable will be:

$var:$#var/2

---

so you could use:

printf '%sn' "$var:0:$#var/2" "$var:$#var/2"

---

You could also use the following awk command:

awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'

---

$ echo abcdef | awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'
abc
def

share|improve this answer

edited May 30 at 22:07

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the response!
  
  – Gabriel Diego
  May 30 at 21:19
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  concise and elegant solution.
  
  – Dudi Boy
  May 30 at 21:32
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  You can get rid of the $((...)); the off and len part of the $var:off:len substitution are already evaluated as arithmetic expressions. Example: foo=01234567; echo "$foo:0:$#foo/2 $foo:$#foo/2". That's documented, and it's the same in zsh and ksh93 as in bash.
  
  – mosvy
  May 30 at 21:47
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  Note: If the length of the string is odd, this will still split it into two parts, but the second will be a character longer.
  
  – peterh
  May 31 at 7:39
  

  
  
  
  

add a comment | 

8

Using split, here strings and command substitution:

var=abcdef
printf '%sn' "$(split -n1/2 <<<$var)" "$(split -n2/2 <<<$var)"

share|improve this answer

answered May 30 at 21:42

FreddyFreddy

4,1431419

add a comment | 

7

Another awk script can be:

echo abcdef | awk 'print substr($0,1,length/2); print substr($0,length/2+1)'

share|improve this answer

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Note that it doesn't work with mawk or busybox awk because of the syntax ambiguity of division / and the /ERE/ operator, and the special case of () being optional for length (still those implementations are not POSIX compliant in that case). Using length() or length($0) here instead of length would help for those. You could also do awk 'BEGINhalf = int(length(ARGV[1]) / 2); print substr(ARGV[1], 1, half) ORS substr(ARGV[1], half+1)' abcdef which would save the pipe and extra process and make it work even if the string contains newline characters.
  
  – Stéphane Chazelas
  May 31 at 10:55
  
  

  
  
  
  

add a comment | 

1

Python 3

s = input() # Take one line of input from stdin.
x = len(s) // 2 # Get middle of string. "//" is floor division
print(s[:x], s[x:], sep="n") # Print "s" up to "x", then "s" past "x", joined on newlines.

For example,

$ echo abcdef | python3 -c 's = input(); x = len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
def

If the string length is not an even number, the second line will be longer. E.g.

$ echo abcdefg | python3 -c 's = input(); x= len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
defg

share|improve this answer

edited May 31 at 14:07

answered May 31 at 14:02

wjandreawjandrea

588414

add a comment | 

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',
autoActivateHeartbeat: false,
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
);



);

Gabriel Diego is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f522052%2fhow-to-split-a-string-in-two-substrings-of-same-length-using-bash%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

16

Using parameter expansion and shell arithmetic:

The first half of the variable will be:

$var:0:$#var/2

The second half of the variable will be:

$var:$#var/2

---

so you could use:

printf '%sn' "$var:0:$#var/2" "$var:$#var/2"

---

You could also use the following awk command:

awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'

---

$ echo abcdef | awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'
abc
def

share|improve this answer

edited May 30 at 22:07

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the response!
  
  – Gabriel Diego
  May 30 at 21:19
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  concise and elegant solution.
  
  – Dudi Boy
  May 30 at 21:32
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  You can get rid of the $((...)); the off and len part of the $var:off:len substitution are already evaluated as arithmetic expressions. Example: foo=01234567; echo "$foo:0:$#foo/2 $foo:$#foo/2". That's documented, and it's the same in zsh and ksh93 as in bash.
  
  – mosvy
  May 30 at 21:47
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  Note: If the length of the string is odd, this will still split it into two parts, but the second will be a character longer.
  
  – peterh
  May 31 at 7:39
  

  
  
  
  

add a comment | 

16

Using parameter expansion and shell arithmetic:

The first half of the variable will be:

$var:0:$#var/2

The second half of the variable will be:

$var:$#var/2

---

so you could use:

printf '%sn' "$var:0:$#var/2" "$var:$#var/2"

---

You could also use the following awk command:

awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'

---

$ echo abcdef | awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'
abc
def

share|improve this answer

edited May 30 at 22:07

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for the response!
  
  – Gabriel Diego
  May 30 at 21:19
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  concise and elegant solution.
  
  – Dudi Boy
  May 30 at 21:32
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  You can get rid of the $((...)); the off and len part of the $var:off:len substitution are already evaluated as arithmetic expressions. Example: foo=01234567; echo "$foo:0:$#foo/2 $foo:$#foo/2". That's documented, and it's the same in zsh and ksh93 as in bash.
  
  – mosvy
  May 30 at 21:47
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  Note: If the length of the string is odd, this will still split it into two parts, but the second will be a character longer.
  
  – peterh
  May 31 at 7:39
  

  
  
  
  

add a comment | 

Using parameter expansion and shell arithmetic:

The first half of the variable will be:

$var:0:$#var/2

The second half of the variable will be:

$var:$#var/2

---

so you could use:

printf '%sn' "$var:0:$#var/2" "$var:$#var/2"

---

You could also use the following awk command:

awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'

---

$ echo abcdef | awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'
abc
def

share|improve this answer

edited May 30 at 22:07

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

$var:0:$#var/2

$var:$#var/2

printf '%sn' "$var:0:$#var/2" "$var:$#var/2"

awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'

$ echo abcdef | awk 'BEGINFS=""for(i=1;i<=NF/2;i++)printf $iprintf "n"for(i=NF/2+1;i<=NF;i++)printf $iprintf "n"'
abc
def

share|improve this answer

edited May 30 at 22:07

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

answered May 30 at 21:18

Jesse_bJesse_b

16.1k34078

8

Using split, here strings and command substitution:

var=abcdef
printf '%sn' "$(split -n1/2 <<<$var)" "$(split -n2/2 <<<$var)"

share|improve this answer

answered May 30 at 21:42

FreddyFreddy

4,1431419

add a comment | 

8

Using split, here strings and command substitution:

var=abcdef
printf '%sn' "$(split -n1/2 <<<$var)" "$(split -n2/2 <<<$var)"

share|improve this answer

answered May 30 at 21:42

FreddyFreddy

4,1431419

add a comment | 

Using split, here strings and command substitution:

var=abcdef
printf '%sn' "$(split -n1/2 <<<$var)" "$(split -n2/2 <<<$var)"

share|improve this answer

answered May 30 at 21:42

FreddyFreddy

4,1431419

var=abcdef
printf '%sn' "$(split -n1/2 <<<$var)" "$(split -n2/2 <<<$var)"

share|improve this answer

answered May 30 at 21:42

FreddyFreddy

4,1431419

answered May 30 at 21:42

FreddyFreddy

4,1431419

answered May 30 at 21:42

FreddyFreddy

4,1431419

7

Another awk script can be:

echo abcdef | awk 'print substr($0,1,length/2); print substr($0,length/2+1)'

share|improve this answer

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Note that it doesn't work with mawk or busybox awk because of the syntax ambiguity of division / and the /ERE/ operator, and the special case of () being optional for length (still those implementations are not POSIX compliant in that case). Using length() or length($0) here instead of length would help for those. You could also do awk 'BEGINhalf = int(length(ARGV[1]) / 2); print substr(ARGV[1], 1, half) ORS substr(ARGV[1], half+1)' abcdef which would save the pipe and extra process and make it work even if the string contains newline characters.
  
  – Stéphane Chazelas
  May 31 at 10:55
  
  

  
  
  
  

add a comment | 

7

Another awk script can be:

echo abcdef | awk 'print substr($0,1,length/2); print substr($0,length/2+1)'

share|improve this answer

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Note that it doesn't work with mawk or busybox awk because of the syntax ambiguity of division / and the /ERE/ operator, and the special case of () being optional for length (still those implementations are not POSIX compliant in that case). Using length() or length($0) here instead of length would help for those. You could also do awk 'BEGINhalf = int(length(ARGV[1]) / 2); print substr(ARGV[1], 1, half) ORS substr(ARGV[1], half+1)' abcdef which would save the pipe and extra process and make it work even if the string contains newline characters.
  
  – Stéphane Chazelas
  May 31 at 10:55
  
  

  
  
  
  

add a comment | 

Another awk script can be:

echo abcdef | awk 'print substr($0,1,length/2); print substr($0,length/2+1)'

share|improve this answer

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

echo abcdef | awk 'print substr($0,1,length/2); print substr($0,length/2+1)'

share|improve this answer

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

answered May 30 at 21:37

Dudi BoyDudi Boy

37127

1

Python 3

s = input() # Take one line of input from stdin.
x = len(s) // 2 # Get middle of string. "//" is floor division
print(s[:x], s[x:], sep="n") # Print "s" up to "x", then "s" past "x", joined on newlines.

For example,

$ echo abcdef | python3 -c 's = input(); x = len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
def

If the string length is not an even number, the second line will be longer. E.g.

$ echo abcdefg | python3 -c 's = input(); x= len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
defg

share|improve this answer

edited May 31 at 14:07

answered May 31 at 14:02

wjandreawjandrea

588414

add a comment | 

1

Python 3

s = input() # Take one line of input from stdin.
x = len(s) // 2 # Get middle of string. "//" is floor division
print(s[:x], s[x:], sep="n") # Print "s" up to "x", then "s" past "x", joined on newlines.

For example,

$ echo abcdef | python3 -c 's = input(); x = len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
def

If the string length is not an even number, the second line will be longer. E.g.

$ echo abcdefg | python3 -c 's = input(); x= len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
defg

share|improve this answer

edited May 31 at 14:07

answered May 31 at 14:02

wjandreawjandrea

588414

add a comment | 

Python 3

s = input() # Take one line of input from stdin.
x = len(s) // 2 # Get middle of string. "//" is floor division
print(s[:x], s[x:], sep="n") # Print "s" up to "x", then "s" past "x", joined on newlines.

For example,

$ echo abcdef | python3 -c 's = input(); x = len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
def

If the string length is not an even number, the second line will be longer. E.g.

$ echo abcdefg | python3 -c 's = input(); x= len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
defg

share|improve this answer

edited May 31 at 14:07

answered May 31 at 14:02

wjandreawjandrea

588414

s = input() # Take one line of input from stdin.
x = len(s) // 2 # Get middle of string. "//" is floor division
print(s[:x], s[x:], sep="n") # Print "s" up to "x", then "s" past "x", joined on newlines.

$ echo abcdef | python3 -c 's = input(); x = len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
def

$ echo abcdefg | python3 -c 's = input(); x= len(s) // 2; print(s[:x], s[x:], sep="n")'
abc
defg

share|improve this answer

edited May 31 at 14:07

answered May 31 at 14:02

wjandreawjandrea

588414

answered May 31 at 14:02

wjandreawjandrea

588414

answered May 31 at 14:02

wjandreawjandrea

588414