sprintf

(PHP 4, PHP 5, PHP 7)

sprintf형식화한 문자열을 반환

설명

string sprintf ( string $format [, mixed $args [, mixed $... ]] )

포맷 문자열 format에 따라 생성한 문자열을 반환합니다.

인수

format

포맷 문자열은 0개 이상의 지시어를 조합합니다: 일반 문자는 (%을 제외하고) 결과에 그대로 복사하고, 변환 특정어는 각각의 인수로 교체한 결과를 가집니다. 이는 sprintf()printf()에 모두 적용됩니다.

각각의 변환 특정어는 퍼센트 기호(%)에 다음의 요소들이 붙어서 구성됩니다:

  1. 선택적인 부호 지정어는 숫자에 부호(-나 +)를 강제합니다. 기본값은 숫자가 음수일때만 - 부호를 사용합니다. 이 지정어는 양수일때도 + 부호를 붙이고, PHP 4.3.0에서 추가되었습니다.
  2. 선택적인 패딩 지정어는 적합한 문자열의 크기를 얻기 위한 패딩에 사용하는 문자를 지정합니다. 이는 스페이스 문자나 0 (제로 문자)일 수 있습니다. 기본값은 스페이스로 채웁니다. 다른 패딩 문자는 작은 따옴표(')를 앞에 붙여서 지정할 수 있습니다. 아래의 예제를 참고하십시오.
  3. 선택적인 정렬 지정어는 결과를 왼쪽 정렬할지, 오른쪽 정렬할 지를 결정합니다. 기본값은 오른쪽 정렬입니다; 여기에 - 문자를 사용하면 왼쪽 정렬이 됩니다.
  4. 선택적인 수, 너비 지정어는 얼마나 많은 문자(최소한)가 결과에 들어갈지를 결정합니다.
  5. 선택적인 정밀도 지정어는 부동소수점 수에서 얼마나 많은 소수점 아래의 수를 표시할지를 결정합니다. 이 지정어를 문자열에 사용하면, 잘라내는 점으로 작동하여 문자열의 최대 문자수를 제한합니다.
  6. 형 지정어는 인수 데이터를 어떤 형으로 취급할지 결정합니다. 가능한 형은:

    • % - 퍼센트 문자. 인수는 필요하지 않습니다.
    • b - 인수를 정수로 취급하고, 2진수로 표현합니다.
    • c - 인수를 정수로 취급하고, 아스키 값에 해당하는 문자로 표현합니다.
    • d - 인수를 정수로 취급하고, (부호 있는) 10진수로 표현합니다.
    • e - 인수를 과학 형식으로 취급합니다. (예. 1.2e+2) 정밀도 지정어는 PHP 5.2.1부터 소수점 아래 자리수를 정합니다. 이전 버전에서는 유효숫자의 갯수(하나 적음)로 취급했었습니다.
    • u - 인수를 정수로 취급하고, 부호 없는 10진수로 표현합니다.
    • f - 인수를 소수로 취급하고, 부동소수점 수로 표현합니다. (로케일 관련)
    • F - 인수를 소수로 취급하고, 부동소수점 수로 표현합니다. (로케일 무관) PHP 4.3.10과 PHP 5.0.3부터 사용할 수 있습니다.
    • o - 인수를 정수로 취급하고, 8진수로 표현합니다.
    • s - 인수를 문자열로 취급하고 표현합니다.
    • x - 인수를 정수로 취급하고 16진수(소문자 표시)로 표현합니다.
    • X - 인수를 정수로 취급하고, 16진수(대문자 표시)로 표현합니다.

포맷 문자열은 인수 넘버링/교환을 지원합니다. 다음은 예제입니다:

Example #1 인수 교환

<?php
$format 
= ;There are %d monkeys in the %s';
printf($format, $num, $location);
?>
이는 "There are 5 monkeys in the tree"를 출력할 것입니다. 그러나, 국제화를 위해서 포맷 문자열을 별도의 파일로 작성하고, 이것을 다음처럼 재작성했다고 생각해봅시다:

Example #2 인수 교환

<?php
$format 
'The %s contains %d monkeys';
printf($format$num$location);
?>
문제가 생겼습니다. 포맷 문자열에서의 순서와 코드에서 인수의 순서가 일치하지 않습니다. 여기서 코드를 수정하지 않고, 단순히 포맷 문자열에 어떤 인수를 가져올지를 지정할 수 있습니다. 포맷 문자열을 다음과 같이 작성하면 됩니다:

Example #3 인수 교환

<?php
$format 
'The %2$s contains %1$d monkeys';
printf($format$num$location);
?>
코드에 많은 인수를 추가하지 않고도 반복해서 출력할 수 있다는 추가적인 장점이 존재합니다. 예를 들면:

Example #4 인수 교환

<?php
$format 
'The %2$s contains %1$d monkeys.
           That\'s a nice %2$s full of %1$d monkeys.'
;
printf($format$num$location);
?>

args

...

반환값

형식화 문자열 format에 따라서 생성된 문자열을 반환합니다.

변경점

버전 설명
4.0.6 인수 넘버링/교환 추가.

예제

Example #5 printf(): 다양한 예제

<?php
$n 
=  43951789;
$u = -43951789;
$c 65// 아스키 65는 'A'

// 이중 %%에 주목, '%' 문자를 출력합니다.
printf("%%b = '%b'\n"$n); // 2진 표현
printf("%%c = '%c'\n"$c); // 아스키 문자 출력, chr() 함수와 동일
printf("%%d = '%d'\n"$n); // 표준 정수
printf("%%e = '%e'\n"$n); // 과학 표현
printf("%%u = '%u'\n"$n); // 양의 정수에 대한 부호 없는 정수 표현
printf("%%u = '%u'\n"$u); // 음의 정수에 대한 부호 없는 정수 표현
printf("%%f = '%f'\n"$n); // 부동소수점 표현
printf("%%o = '%o'\n"$n); // 8진 표현
printf("%%s = '%s'\n"$n); // 문자열 표현
printf("%%x = '%x'\n"$n); // 16진 표현 (소문자)
printf("%%X = '%X'\n"$n); // 16진 표현 (대문자)

printf("%%+d = '%+d'\n"$n); // 양의 정수에 대한 부호지정어
printf("%%+d = '%+d'\n"$u); // 음의 정수에 대한 부호지정어
?>

위 예제의 출력:

%b = '10100111101010011010101101'
%c = 'A'
%d = '43951789'
%e = '4.39518e+7'
%u = '43951789'
%u = '4251015507'
%f = '43951789.000000'
%o = '247523255'
%s = '43951789'
%x = '29ea6ad'
%X = '29EA6AD'
%+d = '+43951789'
%+d = '-43951789'

Example #6 printf(): 문자열 지정어

<?php
$s 
'monkey';
$t 'many monkeys';

printf("[%s]\n",      $s); // 표준 문자열 출력
printf("[%10s]\n"     $s); // 공백으로 오른쪽 정렬
printf("[%-10s]\n",   $s); // 공백으로 왼쪽 정렬
printf("[%010s]\n",   $s); // 0 채우기도 문자열에 작동
printf("[%'#10s]\n",  $s); // 사용자 채우기 문자 '#' 사용
printf("[%10.10s]\n"$t); // 왼쪽 정렬이지만 10문자로 자름
?>

위 예제의 출력:

[monkey]
[    monkey]
[monkey    ]
[0000monkey]
[####monkey]
[many monke]

Example #7 sprintf(): 0으로 채운 정수

<?php
$isodate 
sprintf("%04d-%02d-%02d"$year$month$day);
?>

Example #8 sprintf(): 통화 표현하기

<?php
$money1 
68.75;
$money2 54.35;
$money $money1 $money2;
// echo $money 는 "123.1"를 출력합니다;
$formatted sprintf("%01.2f"$money);
// echo $formatted 는 "123.10"를 출력합니다.
?>

Example #9 sprintf(): 과학 표현

<?php
$number 
362525200;

echo 
sprintf("%.3e"$number); // 3.625e+8 출력
?>

참고

  • printf() - 형식화한 문자열을 출력
  • sscanf() - 문자열을 형식에 따라 해석
  • fscanf() - Parses input from a file according to a format
  • vsprintf() - Return a formatted string
  • number_format() - Format a number with grouped thousands

add a note add a note

User Contributed Notes 40 notes

up
53
Alex R. Gibbs
6 years ago
1.  A plus sign ('+') means put a '+' before positive numbers while a minus sign ('-') means left justify.  The documentation incorrectly states that they are interchangeable.  They produce unique results that can be combined:

<?php
echo sprintf ("|%+4d|%+4d|\n",   1, -1);
echo
sprintf ("|%-4d|%-4d|\n",   1, -1);
echo
sprintf ("|%+-4d|%+-4d|\n", 1, -1);
?>

outputs:

|  +1|  -1|
|1   |-1  |
|+1  |-1  |

2.  Padding with a '0' is different than padding with other characters.  Zeros will only be added at the front of a number, after any sign.  Other characters will be added before the sign, or after the number:

<?php
echo sprintf ("|%04d|\n",   -2);
echo
sprintf ("|%':4d|\n",  -2);
echo
sprintf ("|%-':4d|\n", -2);

// Specifying both "-" and "0" creates a conflict with unexpected results:
echo sprintf ("|%-04d|\n",  -2);

// Padding with other digits behaves like other non-zero characters:
echo sprintf ("|%-'14d|\n", -2);
echo
sprintf ("|%-'04d|\n", -2);
?>

outputs:

|-002|
|::-2|
|-2::|
|-2  |
|-211|
|-2  |
up
40
remy dot damour at -please-no-spam-laposte dot net
10 years ago
With printf() and sprintf() functions, escape character is not backslash '\' but rather '%'.

Ie. to print '%' character you need to escape it with itself:
<?php
printf
('%%%s%%', 'koko'); #output: '%koko%'
?>
up
20
kontakt at myseosolution dot de
4 years ago
There are already some comments on using sprintf to force leading leading zeros but the examples only include integers. I needed leading zeros on floating point numbers and was surprised that it didn't work as expected.

Example:
<?php
sprintf
('%02d', 1);
?>

This will result in 01. However, trying the same for a float with precision doesn't work:

<?php
sprintf
('%02.2f', 1);
?>

Yields 1.00.

This threw me a little off. To get the desired result, one needs to add the precision (2) and the length of the decimal seperator "." (1). So the correct pattern would be

<?php
sprintf
('%05.2f', 1);
?>

Output: 01.00

Please see http://stackoverflow.com/a/28739819/413531 for a more detailed explanation.
up
8
timo dot frenay at gmail dot com
8 years ago
Here is how to print a floating point number with 16 significant digits regardless of magnitude:

<?php
    $result
= sprintf(sprintf('%%.%dF', max(15 - floor(log10($value)), 0)), $value);
?>

This works more reliably than doing something like sprintf('%.15F', $value) as the latter may cut off significant digits for very small numbers, or prints bogus digits (meaning extra digits beyond what can reliably be represented in a floating point number) for very large numbers.
up
10
jfgrissom at gmail dot com
10 years ago
I had a nightmare trying to find the two's complement of a 32 bit number.

I got this from http://www.webmasterworld.com/forum88/13334.htm (credit where credit is due... =P  )

Quote: ...find out the 2's complement of any number, which is -(pow(2, n) - N) where n is the number of bits and N is the number for which to find out its 2's complement.

This worked magic for me... previously I was trying to use

sprintf ("%b",$32BitDecimal);
But it always returned 10000000000000000000000 when the $32BitDecimal value got above 2,000,000,000.

This -(pow(2, n) - N)
Worked remarkably well and was very accurate.

Hope this helps someone fighting with two's complement in PHP.
up
8
viktor at textalk dot com
10 years ago
A more complete and working version of mb_sprintf and mb_vsprintf. It should work with any "ASCII preserving" encoding such as UTF-8 and all the ISO-8859 charsets. It handles sign, padding, alignment, width and precision. Argument swapping is not handled.

<?php
if (!function_exists('mb_sprintf')) {
  function
mb_sprintf($format) {
     
$argv = func_get_args() ;
     
array_shift($argv) ;
      return
mb_vsprintf($format, $argv) ;
  }
}
if (!
function_exists('mb_vsprintf')) {
 
/**
   * Works with all encodings in format and arguments.
   * Supported: Sign, padding, alignment, width and precision.
   * Not supported: Argument swapping.
   */
 
function mb_vsprintf($format, $argv, $encoding=null) {
      if (
is_null($encoding))
         
$encoding = mb_internal_encoding();

     
// Use UTF-8 in the format so we can use the u flag in preg_split
     
$format = mb_convert_encoding($format, 'UTF-8', $encoding);

     
$newformat = ""; // build a new format in UTF-8
     
$newargv = array(); // unhandled args in unchanged encoding

     
while ($format !== "") {
     
       
// Split the format in two parts: $pre and $post by the first %-directive
        // We get also the matched groups
       
list ($pre, $sign, $filler, $align, $size, $precision, $type, $post) =
           
preg_split("!\%(\+?)('.|[0 ]|)(-?)([1-9][0-9]*|)(\.[1-9][0-9]*|)([%a-zA-Z])!u",
                      
$format, 2, PREG_SPLIT_DELIM_CAPTURE) ;

       
$newformat .= mb_convert_encoding($pre, $encoding, 'UTF-8');
       
        if (
$type == '') {
         
// didn't match. do nothing. this is the last iteration.
       
}
        elseif (
$type == '%') {
         
// an escaped %
         
$newformat .= '%%';
        }
        elseif (
$type == 's') {
         
$arg = array_shift($argv);
         
$arg = mb_convert_encoding($arg, 'UTF-8', $encoding);
         
$padding_pre = '';
         
$padding_post = '';
         
         
// truncate $arg
         
if ($precision !== '') {
           
$precision = intval(substr($precision,1));
            if (
$precision > 0 && mb_strlen($arg,$encoding) > $precision)
             
$arg = mb_substr($precision,0,$precision,$encoding);
          }
         
         
// define padding
         
if ($size > 0) {
           
$arglen = mb_strlen($arg, $encoding);
            if (
$arglen < $size) {
              if(
$filler==='')
                 
$filler = ' ';
              if (
$align == '-')
                 
$padding_post = str_repeat($filler, $size - $arglen);
              else
                 
$padding_pre = str_repeat($filler, $size - $arglen);
            }
          }
         
         
// escape % and pass it forward
         
$newformat .= $padding_pre . str_replace('%', '%%', $arg) . $padding_post;
        }
        else {
         
// another type, pass forward
         
$newformat .= "%$sign$filler$align$size$precision$type";
         
$newargv[] = array_shift($argv);
        }
       
$format = strval($post);
      }
     
// Convert new format back from UTF-8 to the original encoding
     
$newformat = mb_convert_encoding($newformat, $encoding, 'UTF-8');
      return
vsprintf($newformat, $newargv);
  }
}
?>
up
8
php at sharpdreams dot com
15 years ago
Note that when using the argument swapping, you MUST number every argument, otherwise sprintf gets confused. This only happens if you use number arguments first, then switch to a non-numbered, and then back to a numbered one.

<?php
$sql
= sprintf( "select * from %1\$s left join %2\$s on( %1\$s.id = %2\$s.midpoint ) where %1\$s.name like '%%%s%%' and %2\$s.tagname is not null", "table1", "table2", "bob" );
// Wont work:
// Sprintf will complain about not enough arguments.
$sql = sprintf( "select * from %1\$s left join %2\$s on( %1\$s.id = %2\$s.midpoint ) where %1\$s.name like '%%%3\$s%%' and %2\$s.tagname is not null", "table1", "table2", "bob" );
// Will work: note the %3\$s
?>
up
15
Jay Gilford
10 years ago
I created this function a while back to save on having to combine mysql_real_escape_string onto all the params passed into a sprintf. it works literally the same as the sprintf other than that it doesn't require you to escape your inputs. Hope its of some use to people

<?php
function mressf()
{
   
$args = func_get_args();
    if (
count($args) < 2)
        return
false;
   
$query = array_shift($args);
   
$args = array_map('mysql_real_escape_string', $args);
   
array_unshift($args, $query);
   
$query = call_user_func_array('sprintf', $args);
    return
$query;
}
?>

Regards
Jay
Jaygilford.com
up
5
john at jbwalker dot com
5 years ago
I couldn't find what should be a WARNING in the documentation above, that if you have more specifiers than variables to match them sprintf returns NOTHING. This fact, IMHO, should also be noted under return values.
up
6
dwieeb at gmail dot com
9 years ago
If you use the default padding specifier (a space) and then print it to HTML, you will notice that HTML does not display the multiple spaces correctly. This is because any sequence of white-space is treated as a single space.

To overcome this, I wrote a simple function that replaces all the spaces in the string returned by sprintf() with the character entity reference "&nbsp;" to achieve non-breaking space in strings returned by sprintf()

<?php
//Here is the function:
function sprintf_nbsp() {
  
$args = func_get_args();
   return
str_replace(' ', '&nbsp;', vsprintf(array_shift($args), array_values($args)));
}

//Usage (exactly like sprintf):
$format = 'The %d monkeys are attacking the [%10s]!';
$str = sprintf_nbsp($format, 15, 'zoo');
echo
$str;
?>

The above example will output:
The 15 monkeys are attacking the [       zoo]!

<?php
//The variation that prints the string instead of returning it:
function printf_nbsp() {
  
$args = func_get_args();
   echo
str_replace(' ', '&nbsp;', vsprintf(array_shift($args), array_values($args)));
}
?>
up
8
Pacogliss
14 years ago
Just a reminder for beginners : example 6 'printf("[%10s]\n",    $s);' only works (that is, shows out the spaces) if you put the html '<pre></pre>' tags ( head-scraping time saver ;-).
up
5
david at rayninfo dot co dot uk
14 years ago
Using sprintf to force leading leading zeros

foreach (range(1, 10) as $v) {echo "<br>tag_".sprintf("%02d",$v);}

displays
tag_01
tag_02
tag_03
.. etc
up
3
no dot email dot address at example dot com
17 years ago
Using argument swapping in sprintf() with gettext: Let's say you've written the following script:

<?php
$var
= sprintf(gettext("The %2\$s contains %1\$d monkeys"), 2, "cage");
?>

Now you run xgettext in order to generate a .po file. The .po file will then look like this:

#: file.php:9
#, ycp-format
msgid "The %2\\$s contains %1\\$d monkeys"
msgstr ""

Notice how an extra backslash has been added by xgettext.

Once you've translated the string, you must remove all backslashes from the ID string as well as the translation, so the po file will look like this:

#: file.php:9
#, ycp-format
msgid "The %2$s contains %1$d monkeys"
msgstr "Der er %1$d aber i %2$s"

Now run msgfmt to generate the .mo file, restart Apache to remove the gettext cache if necessary, and you're off.
up
6
Hayley Watson
7 years ago
If you use argument numbering, then format specifications with the same number get the same argument; this can save repeating the argument in the function call.

<?php

$pattern
= '%1$s %1$\'#10s %1$s!';

printf($pattern, "badgers");
?>
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4
carmageddon at gmail dot com
8 years ago
If you want to convert a decimal (integer) number into constant length binary number in lets say 9 bits, use this:

$binary = sprintf('%08b', $number );

for example:
<?php
$bin
= sprintf('%08b',511 );
echo
$bin."\n";
?>

would output 111111111
And 2 would output 00000010

I know the leading zeros are useful to me, perhaps they are to someone else too.
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7
christian at wenz dot org
14 years ago
@ henke dot andersson at comhem dot se: Use vprintf()/vsprintf() for that.
up
3
hdimac at gmail dot com
5 years ago
In the examples, is being shown printf, but it should say sprintf, which is the function being explained... just a simple edition mistake.
up
1
php at mikeboers dot com
11 years ago
And continuing on the same theme of a key-based sprintf...

I'm roughly (I can see a couple cases where it comes out wierd) copying the syntax of Python's string formatting with a dictionary. The improvement over the several past attempts is that this one still respects all of the formating options, as you can see in my example.

And the error handling is really crappy (just an echo). I just threw this together so do with it what you will. =]

<?php

function sprintf_array($string, $array)
{
   
$keys    = array_keys($array);
   
$keysmap = array_flip($keys);
   
$values  = array_values($array);
   
    while (
preg_match('/%\(([a-zA-Z0-9_ -]+)\)/', $string, $m))
    {   
        if (!isset(
$keysmap[$m[1]]))
        {
            echo
"No key $m[1]\n";
            return
false;
        }
       
       
$string = str_replace($m[0], '%' . ($keysmap[$m[1]] + 1) . '$', $string);
    }
   
   
array_unshift($values, $string);
   
var_dump($values);
    return
call_user_func_array('sprintf', $values);
}

echo
sprintf_array('4 digit padded number: %(num)04d ', array('num' => 42));

?>

Cheers!
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5
jaimthorn at yahoo dot com
11 years ago
I needed a piece of code similar to the one Matt posted below, on the 10th of March, 2008.  However, I wasn't completely satisfied with Matt's code (sorry, Matt!  No offense intended!), because

1) I don't like to initialize variables when it's not really needed, and
2) it contains two bugs.

What are the bugs?

First, Matt's code tests for count($vars) > 0, but if $var == "Hello world!", then count($var) == 1, but the foreach() will crash because $var has to be an array.  So instead, my code tests for is_array($var).

Second, if a key in $vars is a prefix of any of the later keys in the array (like 'object' is the beginning of 'objective') then the str_replace messes things up.  This is no big deal if your keys are hard-coded and you can make sure the keys don't interfere, but in my code the keys are variable.  So I decided to first sort the array on a decreasing length of the key.

<?php

function cmp($a, $b)
{
    return
strlen($b) - strlen($a);
}

function
sprintf2($str, $vars, $char = '%')
{
    if(
is_array($vars))
    {
       
uksort($vars, "cmp");

        foreach(
$vars as $k => $v)
        {
           
$str = str_replace($char . $k, $v, $str);
        }
    }

    return
$str;
}

echo
sprintf2( 'Hello %your_name, my name is %my_name! I am %my_age, how old are you? I like %object and I want to %objective_in_life!'
            
, array( 'your_name'         => 'Matt'
                   
, 'my_name'           => 'Jim'
                   
, 'my_age'            => 'old'
                   
, 'object'            => 'women'
                   
, 'objective_in_life' => 'write code'
                   
)
             );

?>

If possible, and if you're willing, you can also embed the key fields in the text between percent-signs, rather than prefixing the keys with one.  Sorting is no longer necessary, and the execution time is less than half of the code above:

<?php

function sprintf3($str, $vars, $char = '%')
{
   
$tmp = array();
    foreach(
$vars as $k => $v)
    {
       
$tmp[$char . $k . $char] = $v;
    }
    return
str_replace(array_keys($tmp), array_values($tmp), $str);
}

echo
sprintf3( 'Hello %your_name%, my name is %my_name%! I am %my_age%, how old are you? I like %object% and I want to %objective_in_life%!'
            
, array( 'your_name'         => 'Matt'
                   
, 'my_name'           => 'Jim'
                   
, 'my_age'            => 'old'
                   
, 'object'            => 'women'
                   
, 'objective_in_life' => 'write code'
                   
)
             );
?>

If you're willing to embed the keys in the text, you may also be willing to embed the keys themselves in percent signs, thus shaving off another 30% of the execution time:

<?php

function sprintf4($str, $vars)
{
    return
str_replace(array_keys($vars), array_values($vars), $str);
}

echo
sprintf4( 'Hello %your_name%, my name is %my_name%! I am %my_age%, how old are you? I like %object% and I want to %objective_in_life%!'
            
, array( '%your_name%'         => 'Matt'
                   
, '%my_name%'           => 'Jim'
                   
, '%my_age%'            => 'old'
                   
, '%object%'            => 'women'
                   
, '%objective_in_life%' => 'write code'
                   
)
             );
?>

Of course, by now the sprintf function is no longer something you'd want to write to mum and dad about...
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2
abiltcliffe at bigfoot.com
17 years ago
To jrust at rustyparts.com, note that if you're using a double-quoted string and *don't* escape the dollar sign with a backslash, $s and $d will be interpreted as variable references. The backslash isn't part of the format specifier itself but you do need to include it when you write the format string (unless you use single quotes).
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3
krzysiek dot 333 at gmail dot com - zryty dot hekko dot pl
8 years ago
Encoding and decoding IP adress to format: 1A2B3C4D (mysql column: char(8) )

<?php
function encode_ip($dotquad_ip)
{
   
$ip_sep = explode('.', $dotquad_ip);
    return
sprintf('%02x%02x%02x%02x', $ip_sep[0], $ip_sep[1], $ip_sep[2], $ip_sep[3]);
}

function
decode_ip($int_ip)
{
   
$hexipbang = explode('.', chunk_split($int_ip, 2, '.'));
    return
hexdec($hexipbang[0]). '.' . hexdec($hexipbang[1]) . '.' . hexdec($hexipbang[2]) . '.' . hexdec($hexipbang[3]);
}
?>
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3
splogamurugan at gmail dot com
10 years ago
$format = 'There are %1$d monkeys in the %s and %s ';
printf($format, 100, 'Chennai', 'Bangalore');

Expecting to output
"There are 100 monkeys in the Chennai and bangalore"

But, this will output
"There are 100 monkeys in the 100 and Chennai"

Because, the second and Third specifiers takes 1rst and 2nd arguments. Because it is not assigned with any arguments.
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4
nate at frickenate dot com
10 years ago
Here's a clean, working version of functions to allow using named arguments instead of numeric ones. ex: instead of sprintf('%1$s', 'Joe');, we can use sprintf('%name$s', array('name' => 'Joe'));. I've provided 2 different versions: the first uses the php-like syntax (ex: %name$s), while the second uses the python syntax (ex: %(name)s).

<?php

/**
* version of sprintf for cases where named arguments are desired (php syntax)
*
* with sprintf: sprintf('second: %2$s ; first: %1$s', '1st', '2nd');
*
* with sprintfn: sprintfn('second: %second$s ; first: %first$s', array(
*  'first' => '1st',
*  'second'=> '2nd'
* ));
*
* @param string $format sprintf format string, with any number of named arguments
* @param array $args array of [ 'arg_name' => 'arg value', ... ] replacements to be made
* @return string|false result of sprintf call, or bool false on error
*/
function sprintfn ($format, array $args = array()) {
   
// map of argument names to their corresponding sprintf numeric argument value
   
$arg_nums = array_slice(array_flip(array_keys(array(0 => 0) + $args)), 1);

   
// find the next named argument. each search starts at the end of the previous replacement.
   
for ($pos = 0; preg_match('/(?<=%)([a-zA-Z_]\w*)(?=\$)/', $format, $match, PREG_OFFSET_CAPTURE, $pos);) {
       
$arg_pos = $match[0][1];
       
$arg_len = strlen($match[0][0]);
       
$arg_key = $match[1][0];

       
// programmer did not supply a value for the named argument found in the format string
       
if (! array_key_exists($arg_key, $arg_nums)) {
           
user_error("sprintfn(): Missing argument '${arg_key}'", E_USER_WARNING);
            return
false;
        }

       
// replace the named argument with the corresponding numeric one
       
$format = substr_replace($format, $replace = $arg_nums[$arg_key], $arg_pos, $arg_len);
       
$pos = $arg_pos + strlen($replace); // skip to end of replacement for next iteration
   
}

    return
vsprintf($format, array_values($args));
}

/**
* version of sprintf for cases where named arguments are desired (python syntax)
*
* with sprintf: sprintf('second: %2$s ; first: %1$s', '1st', '2nd');
*
* with sprintfn: sprintfn('second: %(second)s ; first: %(first)s', array(
*  'first' => '1st',
*  'second'=> '2nd'
* ));
*
* @param string $format sprintf format string, with any number of named arguments
* @param array $args array of [ 'arg_name' => 'arg value', ... ] replacements to be made
* @return string|false result of sprintf call, or bool false on error
*/
function sprintfn ($format, array $args = array()) {
   
// map of argument names to their corresponding sprintf numeric argument value
   
$arg_nums = array_slice(array_flip(array_keys(array(0 => 0) + $args)), 1);

   
// find the next named argument. each search starts at the end of the previous replacement.
   
for ($pos = 0; preg_match('/(?<=%)\(([a-zA-Z_]\w*)\)/', $format, $match, PREG_OFFSET_CAPTURE, $pos);) {
       
$arg_pos = $match[0][1];
       
$arg_len = strlen($match[0][0]);
       
$arg_key = $match[1][0];

       
// programmer did not supply a value for the named argument found in the format string
       
if (! array_key_exists($arg_key, $arg_nums)) {
           
user_error("sprintfn(): Missing argument '${arg_key}'", E_USER_WARNING);
            return
false;
        }

       
// replace the named argument with the corresponding numeric one
       
$format = substr_replace($format, $replace = $arg_nums[$arg_key] . '$', $arg_pos, $arg_len);
       
$pos = $arg_pos + strlen($replace); // skip to end of replacement for next iteration
   
}

    return
vsprintf($format, array_values($args));
}

?>
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6
matt
11 years ago
Was looking for a assoc way of using sprintf but couldnt find one, probably wasnt looking hard enough so came up with this. Very very simple indeed...

<?php

function sprintf2($str='', $vars=array(), $char='%')
{
    if (!
$str) return '';
    if (
count($vars) > 0)
    {
        foreach (
$vars as $k => $v)
        {
           
$str = str_replace($char . $k, $v, $str);
        }
    }

    return
$str;
}

echo
sprintf2('Hello %your_name my name is %my_name! I am %my_age, how old are you? I like %object!', array(
   
'your_name' => 'Ben',
   
'my_name' => 'Matt',
   
'my_age' => '21',
   
'object' => 'food'
));

// Hello Ben my name is Matt! I am 21, how old are you? I like food!

?>

Looks nice anyway :)
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2
Andrew dot Wright at spamsux dot atnf dot csiro dot au
17 years ago
An error in my last example:
$b = sprintf("%30.s", $a);
will only add enough spaces before $a to pad the spaces + strlen($a) to 30 places.

My method of centering fixed text in a 72 character width space is:

$a = "Some string here";
$lwidth = 36; // 72/2
$b = sprintf("%".($lwidth + round(strlen($a)/2)).".s", $a);
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2
Astone
10 years ago
When you're using Google translator, you have to 'escape' the 'conversion specifications' by putting <span class="notranslate"></span> around them.

Like this:

<?php

function getGoogleTranslation($sString, $bEscapeParams = true)
{
   
// "escape" sprintf paramerters
   
if ($bEscapeParams)
    {
       
$sPatern = '/(?:%%|%(?:[0-9]+\$)?[+-]?(?:[ 0]|\'.)?-?[0-9]*(?:\.[0-9]+)?[bcdeufFosxX])/';       
       
$sEscapeString = '<span class="notranslate">$0</span>';
       
$sString = preg_replace($sPatern, $sEscapeString, $sString);
    }

   
// Compose data array (English to Dutch)
   
$aData = array(
       
'v'            => '1.0',
       
'q'            => $sString,
       
'langpair'    => 'en|nl',
    );

   
// Initialize connection
   
$rService = curl_init();
   
   
// Connection settings
   
curl_setopt($rService, CURLOPT_URL, 'http://ajax.googleapis.com/ajax/services/language/translate');
   
curl_setopt($rService, CURLOPT_RETURNTRANSFER, true);
   
curl_setopt($rService, CURLOPT_POSTFIELDS, $aData);
   
   
// Execute request
   
$sResponse = curl_exec($rService);

   
// Close connection
   
curl_close($rService);
   
   
// Extract text from JSON response
   
$oResponse = json_decode($sResponse);
    if (isset(
$oResponse->responseData->translatedText))
    {
       
$sTranslation = $oResponse->responseData->translatedText;
    }
    else
    {
       
// If some error occured, use the original string
       
$sTranslation = $sString;
    }
   
   
// Replace "notranslate" tags
   
if ($bEscapeParams)
    {
       
$sEscapePatern = '/<span class="notranslate">([^<]*)<\/span>/';
       
$sTranslation = preg_replace($sEscapePatern, '$1', $sTranslation);
    }
   
   
// Return result
   
return $sTranslation;
}

?>

Thanks to MelTraX for defining the RegExp!
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2
ian dot w dot davis at gmail dot com
14 years ago
Just to elaborate on downright's point about different meanings for %f, it appears the behavior changed significantly as of 4.3.7, rather than just being different on different platforms. Previously, the width specifier gave the number of characters allowed BEFORE the decimal. Now, the width specifier gives the TOTAL number of characters. (This is in line with the semantics of printf() in other languages.) See bugs #28633 and #29286 for more details.
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2
John Walker
10 years ago
To add to other notes below about floating point problems, I noted that %f and %F will apparently output a maximum precision of 6 as a default so you have to specify 1.15f (eg) if you need more.

In my case, the input (from MySQL) was a string with 15 digits of precision that was displayed with 6. Likely what happens is that the rounding occurs in the conversion to a float before it is displayed. Displaying it as 1.15f (or in my case, %s) shows the correct number.
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1
jrpozo at conclase dot net
14 years ago
Be careful if you use the %f modifier to round decimal numbers as it (starting from 4.3.10) will no longer produce a float number if you set certain locales, so you can't accumulate the result. For example:

setlocale(LC_ALL, 'es_ES');
echo(sprintf("%.2f", 13.332) + sprintf("%.2f", 14.446))

gives 27 instead of 27.78, so use %F instead.
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2
thavarajan at gmail dot com
1 year ago
<?php
echo sprintf("%+08d", 0). "<Br>";
echo
sprintf("%+07d", 0). "<Br>";
echo
sprintf("%+06d", 0). "<Br>";
?>

Will produce an output
+0000000
+000000
+00000
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1
Anonymous
2 years ago
Be cafeful while trying to refactor longer strings with repeated placeholders like

    sprintf("Hi %s. Your name is %s", $name, $name);

to use argument numbering:

   sprintf("Hi %1$s. Your name is %1$s", $name);

This will nuke you at **runtime**, because of `$s` thing being handled as variable. If you got no $s for substitution, notice will be thrown.

The solution is to use single quotes to prevent variable substitution in string:

   sprintf('Hi %1$s. Your name is %1$s', $name);

If you need variable substitution, then you'd need to split your string to keep it in single quotes:

   sprintf("Hi " . '%1$s' . ". Your {$variable} is " . '%1$s', $name);
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0
Nathan Alan
2 years ago
Just wanted to add that to get the remaining text from the string, you need to add the following as a variable in your scanf

%[ -~]

Example:

sscanf($sql, "[%d,%d]%[ -~]", $sheet_id, $column, $remaining_sql);
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0
Sam Bull
4 years ago
Fix for sprintfn function for named arguments (http://php.net/manual/en/function.sprintf.php#94608):

Change the first line from:
  $arg_nums = array_slice(array_flip(array_keys(array(0 => 0) + $args)), 1);
to:
  $arg_nums = array_keys($args);
  array_unshift($arg_nums, 0);
  $arg_nums = array_flip(array_slice($arg_nums, 1, NULL, true));
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0
nmmm at nmmm dot nu
4 years ago
php printf and sprintf not seems to support star "*" formatting.

here is an example:

printf("%*d\n",3,5);

this will print just "d" instead of "<two spaces>5"
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-1
Anonymous
11 months ago
I have written a wrapper for sprintf. Add a new %S  (upper case s) where the number indicates the number of characters and not bytes.
This is useful for formatting utf-8 strings.

<?php
function SacSprintf( $format) {
       
$argv = func_get_args() ;
       
array_shift($argv) ;

       
$offset = 0;
       
$i = 0;
        while(
preg_match("^A%[+-]*[.]*([0-9.]*)([a-z])^Ai", $format, $match, PREG_OFFSET_CAPTURE, $offset)) {
                if(
$match[2][0] == 'S') {
                        if(
$match[1][0] != '') {
                               
$t1 = explode('.', $match[1][0]);
                               
$t1[0] = intval($t1[0]) + strlen($argv[$i]) - strlen(utf8_decode($argv[$i]));
                               
$l1 = strlen($match[1][0]);
                               
$t2 = implode('.', $t1);
                               
$l2 = strlen($t2) - $l1;
                               
$format = substr_replace( $format, $t2, $match[1][1], strlen($match[1][0]));
                               
$offset += $l2;
                               
$match[2][1] += $l2;
                        }   
                       
$format[$match[2][1]] = 's';
                }   
               
$offset += $match[2][1];
               
$i++;
        }   
        return
vsprintf($format, $argv) ;
}

echo
"<pre>\n";
echo
"      1234567890123456789012345678901234567890\n";
echo
sprintf("Hola, %-20s is my name\n", "José Luis jiménez");
echo
SacSprintf("Hola, %-20S is my name\n", "José Luis jiménez");
echo
"</pre>\n";
?>

The output will be:
      1234567890123456789012345678901234567890
Hola, José Luis jiménez  is my name
Hola, José Luis jiménez    is my name
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0
ivan at php dot net
5 years ago
There is a minor issue in a code of mb_vsprintf function from viktor at textalk dot com.

In "truncate $arg" section the following line:
  $arg = mb_substr($precision,0,$precision,$encoding);
needs to be replaced with:
  $arg = mb_substr($arg,0,$precision,$encoding);
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0
ignat dot scheglovskiy at gmail dot com
7 years ago
Here is an example how alignment, padding and precision specifier can be used to print formatted list of items:

<?php

$out
= "The Books\n";
$books = array("Book 1", "Book 2", "Book 3");
$pages = array("123 pages ", "234 pages", "345 pages");
for (
$i = 0; $i < count($books); $i++) {
   
$out .= sprintf("%'.-20s%'.7.4s\n", $books[$i], $pages[$i]);
}
echo
$out;

// Outputs:
//
// The Books
// Book 1.................123
// Book 2.................234
// Book 3.................345
?>
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0
geertdd at gmail dot com
9 years ago
Note that when using a sign specifier, the number zero is considered positive and a "+" sign will be prepended to it.

<?php
printf
('%+d', 0); // +0
?>
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0
scott dot gardner at mac dot com
11 years ago
In the last example of Example#6, there is an error regarding the output.

printf("[%10.10s]\n", $t); // left-justification but with a cutoff of 10 characters

This outputs right-justified.

In order to output left-justified:

printf("[%-10.10s]\n", $t);
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0
me at umarfarooq dot net
12 years ago
/**
This function returns a formated  string with the legnth you specify
@string holds the string which you want to format
@len holds the length you want to format
**/
function formatString($string, $len)
{
    if (strlen($string) < $len)
    {
        $addchar=($len - strlen($string)) ;
        for ($i = 0; $i < $addchar; $i++)
        {
            $string=sprintf("$string%s", "0");
        }
    }
   
    if (strlen($string) > $len)
    {
        $string=substr($string,0,$len);
    }
   
    return $string;   
}
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