How long is this string?

Question

It's strange this question hasn't been asked yet, so here it is:

Calculate the length of a string given through STDIN

Rules

• As said, your string will be given through STDIN, not via command line arguments

• Print the length of the string to STDOUT

• Only ASCII chars will be given, and all printable ASCII chars count!

• This is a code-golf, so the answer with the shortest length wins!

Good Luck and have fun!

Answer 1

Shakespeare Programming Language, 156 bytes

Thanks JoKing for nice trick with [Exeunt].

,.Ajax,.Page,.Act I:.Scene I:.[Exeunt][Enter Ajax and Page]Ajax:Open mind Be you nicer zero?Page:If soyou be the sum ofa cat you.If solet usact I.Open heart

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Answer 2

Golfscript (1 byte)

,

And that's why this question hadn't already been asked.

Answer 3

05AB1E, 1 byte

g

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Explanation:
(As if it would be necessary..)

     # Implicit input from STDIN
g    # Length
     # Implicit output to STDOUT

Answer 4

Java 8, 63 bytes

A lambda taking empty input and throwing IOException.

n->{int c=0;while(System.in.read()>=0)c++;System.out.print(c);}

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Answer 5

brainfuck, 163 bytes

,[>+<,]>[>>+>+<<<-]>>>[<<<+>>>-]<<+>[<->[>++++++++++<[->-[>+>>]>[+[-<+>]>+>>]<<<<<]>[-]++++++++[<++++++>-]>[<<+>>-]>[<<+>>-]<<]>]<[->>++++++++[<++++++>-]]<[.[-]<]<

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Somebody had to make this a little interesting.

Explanation:

,[>+<,]>

This is a modified cat program that, rather than outputting each read value, increments the 2nd cell each time a value is read.

The entire rest of the program is for outputting a cell's value as a number rather than an ASCII codepoint.

Answer 6

Hexagony, 11 bytes

,~<@!"/>"){

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More readable version:

  , ~ <
 @ ! " /
> " ) { . 
 . . . .
  . . .

Answer 7

Pyth, 2 bytes

lz

Explanation

l          #length of
 z         #input

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Answer 8

Haskell, 25 20 bytes

^{-5 bytes for making this a function only (initially thought that it has to be a full program)}

interact$show.length

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Answer 9

Brain-Flak + -a flag, 6 bytes

Even Brain-Flak has a built-in for this challenge...

([]<>)

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Without using [] but still rather simple (10 bytes): ({<{}>()})

Answer 10

Whitespace, 73 64 bytes

[S S S N
_Push_0][N
S S N
_Create_Label_LOOP][S N
S _Duplicate][S N
S _Duplicate][T N
T   S _Read_STDIN_as_character][T   T   T   _Retrieve][S S S T  S T T   S T T   S N
_Push_182][T    S S T   _Subtract][N
T   S S N
_If_0_jump_to_Label_PRINT_AND_EXIT][S S S T N
_Push_1][T  S S S _Add][N
S N
N
_Jump_to_Label_LOOP][N
S S S N
_Create_Label_PRINT_AND_EXIT][T N
S T _Print_to_STDOUT]

Letters S (space), T (tab), and N (new-line) added as highlighting only.
[..._some_action] added as explanation only.

Input requires a trailing ¶, because Whitespace has no way to tell when the input-characters are complete. Whitespace only has two STDIN inputs: integer or character. A full string should be inputted one by one, but Whitespace doesn't know when it has all. So perhaps this answer is non-competing due to the restriction of Whitespace, but I've chosen a character outside the printable ASCII range to add as leading character for inputs, so the program knows when to stop and output the length.

Try it online (with raw spaces, tabs and new-lines only).

Explanation in pseudo-code:

Integer counter = 0
Start LOOP:
  Integer input = STDIN as character
  If(input == '¶')
    Jump to function PRINT_AND_EXIT
  counter = counter + 1
  Jump to next iteration of LOOP

function PRINT_AND_EXIT:
  Print counter as integer to STDOUT

Example input: acb¶

Command        Explanation                 Stack        HEAP                    STDIN   STDOUT  STDERR

SSSN           Push 0                      [0]
NSSN           Create Label_LOOP           [0]
 SNS           Duplicate top (0)           [0,0]
 SNS           Duplicate top (0)           [0,0,0]
 TNTS          Read STDIN as character     [0,0]        {0:97}                  'a'
 TTT           Retrieve                    [0,97]       {0:97}
 SSSTSTTSTTSN  Push 182                    [0,97,182]   {0:97}
 TSST          Subtract top two (97-182)   [0,-85]      {0:97}
 NTSSN         If 0: Jump to Label_EXIT    [0]          {0:97}
 SSSTN         Push 1                      [0,1]        {0:97}
 TSSS          Add top two (0+1)           [1]          {0:97}
 NSNN          Jump to Label_LOOP          [1]          {0:97}

 SNS           Duplicate top (1)           [1,1]        {0:97}
 SNS           Duplicate top (1)           [1,1,1]      {0:97}
 TNTS          Read STDIN as character     [1,1]        {0:97,1:99}             'c'
 TTT           Retrieve                    [1,99]       {0:97,1:99}
 SSSTSTTSTTSN  Push 182                    [1,99,182]   {0:97,1:99}
 TSST          Subtract top two (99-182)   [1,-83]      {0:97,1:99}
 NTSSN         If 0: Jump to Label_EXIT    [1]          {0:97,1:99}
 SSSTN         Push 1                      [1,1]        {0:97,1:99}
 TSSS          Add top two (1+1)           [2]          {0:97,1:99}
 NSNN          Jump to Label_LOOP          [2]          {0:97,1:99}

 SNS           Duplicate top (2)           [2,2]        {0:97,1:99}
 SNS           Duplicate top (2)           [2,2,2]      {0:97,1:99}
 TNTS          Read STDIN as character     [2,2]        {0:97,1:99,2:98}        'b'
 TTT           Retrieve                    [2,98]       {0:97,1:99,2:98}
 SSSTSTTSTTSN  Push 182                    [2,98,182]   {0:97,1:99,2:98}
 TSST          Subtract top two (98-182)   [2,-84]      {0:97,1:99,2:98}
 NTSSN         If 0: Jump to Label_EXIT    [2]          {0:97,1:99,2:98}
 SSSTN         Push 1                      [2,1]        {0:97,1:99,2:98}
 TSSS          Add top two (2+1)           [3]          {0:97,1:99,2:98}
 NSNN          Jump to Label_LOOP          [3]          {0:97,1:99,2:98}

 SNS           Duplicate top (3)           [3,3]        {0:97,1:99,2:98}
 SNS           Duplicate top (3)           [3,3,3]      {0:97,1:99,2:98}
 TNTS          Read STDIN as character     [3,3]        {0:97,1:99,2:98,3:182}  '¶'
 TTT           Retrieve                    [3,182]      {0:97,1:99,2:98,3:182}
 SSSTSTTSTTSN  Push 182                    [3,182,182]  {0:97,1:99,2:98,3:182}
 TSST          Subtract top two (182-182)  [3,0]        {0:97,1:99,2:98,3:182}
 NTSSN         If 0: Jump to Label_EXIT    [3]          {0:97,1:99,2:98,3:182}

NSSSN          Create Label_EXIT           [3]          {0:97,1:99,2:98,3:182}
 TNST          Print as integer to STDOUT  []                                          3
                                                                                               error

Stops program with error: No exit defined.

Answer 11

APL+WIN, 2 bytes

Prompts for character string input then counts characters:

⍴⍞

Answer 12

Keg, 3 bytes

?!.

Well, I can't golf this program well.

TIO

Answer 13

Octave, 14 bytes

nnz(input(''))

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Answer 14

R, 23 bytes

cat(nchar(readLines()))

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Answer 15

Retina, 3 bytes

s`.

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This isn't even technically a built-in function, but it is a central feature of the language: counting matches of a regular expression, in this case . (wildcard matching any character). The ` makes Retina treat the character(s) preceding it in the line as configuration, so s activates SingleLine mode, which makes . match newlines also, because they are part of printable ASCII.

Answer 16

Batch, 182 bytes

@set s=
@set/ps=
@set "t=%s:"=""%"
@if "%t:"=""%"=="""=""""" goto g
@for %%s in ("%s:"=%" "%t%")do @echo(%%~s>>_
@for %%s in (_)do @set s=%%~zs
@del _
:g
@cmd/cset/as/2-2*!!s

Testing for the empty string without breaking when quotes were present was cumbersome! Explanation:

@set s=

Clear s as set/p leaves s unchanged if the input was empty.

@set/ps=

Take input on STDIN into s.

@set "t=%s:"=""%"

Try to quote all of the quotes in s. However, if s is empty, Batch throws a wobbly, and sets t to "="" instead, which still has an odd number of quotes.

@if "%t:"=""%"=="""=""""" goto g

Quote all of the quotes in t, and compare the result to ""="""". This can only happen if s was empty, in which case we skip the measurement step.

@for %%s in ("%s:"=%" "%t%")do @echo(%%~s>>_

Print s without quotes and s with quoted quotes on separate lines to a temporary file. The ( is needed in case s only contains quotes.

@for %%s in (_)do @set s=%%~zs

Obtain the length of the temporary file.

@del _

Delete the temporary file.

:g

Jump here if the input was empty.

@cmd/cset/as/2-2*!!s

Halve and subtract 2 from the length of the temporary file. However if the input was empty then s will be treated as the numeric value zero, and the result of the expression is then zero as desired.

117 bytes without empty string support:

@set/ps=
@for %%s in ("%s:"=%" "%s:"=""%")do @echo(%%~s>>_
@for %%s in (_)do @set s=%%~zs
@del _
@cmd/cset/as/2-2

93 bytes if support for "s is not necessary (84 bytes without " or empty string support):

@set s=
@set/ps=
@set n=0
:l
@if not "%s%"=="" set/an+=1&set "s=%s:~1%"&goto l
@echo %n%

Empty strings and quotes can even be handled for 212 bytes without resorting to file length builtins:

@set s=
@set/ps=
@set "t=%s:"=""%"
@set n=0
@if "%t:"=""%"=="""=""""" goto g
:l
@set/an+=1
@set "s=%t:~,1%%t:~,1%"
@if "%s%" neq """" set "t=.%t%"
@set "t=%t:~2%"
@if not "%t%"=="" goto l
:g
@echo %n%

Here after quoting the quotes in s we have to be careful to double the first character of t in case it is a quote, then if it is not then prefix a dummy character to t so that the first two characters may be safely removed. This ends up counting the quoted quotes as single characters again.

Answer 17

Ruby, 16 Bytes

This was rather easy.

puts gets.length

needs no explanation ;)

Answer 18

Perl 6,  15  14 bytes

slurp.codes.say

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say +$*IN.comb

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---

• slurp reads everything
• codes gets the number of Unicode codepoints
  (this is different than chars for \r\n)
• say print the .gist with trailing newline
  (put could have been used, which just adds the newline)
• &prefix:« + » converts to Numeric
• $*IN is STDIN
• comb splits its input into a sequence of characters
  (Which when converted to Numeric returns a count)

Answer 19

Python 3, 19 bytes

print(len(input()))

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Answer 20

W s, 1 byte

k

Explanation

% s: we have to read from STDIN.
% Implicitly prepend an input
k % (k)ount the number of items in this thing
% Implicit output

How do I use the parameter?

The cli param system is quite weird (to allow people to type less), so here is an example of how it is used:

$ ..\python W.py code.w [] s
'Hello'
Code: k
#0: a []
#1: k ['a[0]']
out: lambda a:mylen(a[0])
5