Extracted from Pike v7.6 release 61 at 2005-12-30.
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Method sprintf()


Method sprintf

string sprintf(string format, mixed ... args)

Description

Print formated output to string.

The format string is a string containing a description of how to output the data in args . This string should generally speaking have one %<modifiers><operator> format specifier (examples: %s, %0d, %-=20s) for each of the arguments.

The following modifiers are supported:

'0'

Zero pad numbers (implies right justification).

'!'

Toggle truncation.

' '

Pad positive integers with a space.

'+'

Pad positive integers with a plus sign.

'-'

Left adjust within field size (default is right).

'|'

Centered within field size.

'='

Column mode if strings are greater than field size.

'/'

Rough line break (break at exactly field size instead of between words).

'#'

Table mode, print a list of '\n' separated word (top-to-bottom order).

'$'

Inverse table mode (left-to-right order).

'n'

(Where n is a number or *) field size specifier.

'.n'

Precision specifier.

':n'

Field size precision specifier.

';n'

Column width specifier.

'*'

If n is a * then next argument is used for precision/field size.

"'"

Set a pad string. ' cannot be a part of the pad string (yet).

'~'

Get pad string from argument list.

'<'

Use same argument again.

'^'

Repeat this on every line produced.

'@'

Repeat this format for each element in the argument array.

'>'

Put the string at the bottom end of column instead of top.

'_'

Set width to the length of data.

'[n]'

Select argument number n. Use * to use the next argument as selector.


The following operators are supported:

'%'

Percent.

'b'

Signed binary integer.

'd'

Signed decimal integer.

'u'

Unsigned decimal integer.

'o'

Signed octal integer.

'x'

Lowercase signed hexadecimal integer.

'X'

Uppercase signed hexadecimal integer.

'c'

Character. If a fieldsize has been specified this will output the low-order bytes of the integer in network (big endian) byte order. To get little endian byte order, negate the field size.

'f'

Float. (Locale dependent formatting.)

'g'

Heuristically chosen representation of float. (Locale dependent formatting.)

'G'

Like %g, but uses uppercase E for exponent.

'e'

Exponential notation float. (Locale dependent output.)

'E'

Like %e, but uses uppercase E for exponent.

'F'

Binary IEEE representation of float (%4F gives single precision, %8F gives double precision.)

's'

String.

'O'

Any value, debug style. Do not rely on the exact formatting; how the result looks can vary depending on locale, phase of the moon or anything else the _sprintf method implementor wanted for debugging.

'n'

No operation (ignore the argument).

't'

Type of the argument.

'{'

Perform the enclosed format for every element of the argument array.

'}'

Most modifiers and operators are combinable in any fashion, but some combinations may render strange results.

If an argument is an object that implements lfun::_sprintf() , that callback will be called with the operator as the first argument, and the current modifiers as the second. The callback is expected to return a string.

Example

Pike v7.4 release 13 running Hilfe v3.5 (Incremental Pike Frontend) > sprintf("The unicode character %c has character code %04X.", 'A', 'A'); (1) Result: "The unicode character A has character code 0041." > sprintf("#%@02X is the HTML code for purple.", Image.Color.purple->rgb()); (2) Result: "#A020F0 is the HTML code for purple." > int n=4711; > sprintf("%d = hexadecimal %x = octal %o = %b binary", n, n, n, n); (3) Result: "4711 = hexadecimal 1267 = octal 11147 = 1001001100111 binary"

Note

sprintf style formatting is applied by many formatting functions, such write() and werror .

Example

> write(#"Formatting examples: Left adjusted [%-10d] Centered [%|10d] Right adjusted [%10d] Zero padded [%010d] ", n, n, n, n); Formatting examples: Left adjusted [4711 ] Centered [ 4711 ] Right adjusted [ 4711] Zero padded [0000004711] (5) Result: 142 int screen_width=70; > write("%-=*s\n", screen_width, >> "This will wordwrap the specified string within the "+ >> "specified field size, this is useful say, if you let "+ >> "users specify their screen size, then the room "+ >> "descriptions will automagically word-wrap as appropriate.\n"+ >> "slosh-n's will of course force a new-line when needed.\n"); This will wordwrap the specified string within the specified field size, this is useful say, if you let users specify their screen size, then the room descriptions will automagically word-wrap as appropriate. slosh-n's will of course force a new-line when needed. (6) Result: 355 > write("%-=*s %-=*s\n", screen_width/2, >> "Two columns next to each other (any number of columns will "+ >> "of course work) independantly word-wrapped, can be useful.", >> screen_width/2-1, >> "The - is to specify justification, this is in addherence "+ >> "to std sprintf which defaults to right-justification, "+ >> "this version also supports centre and right justification."); Two columns next to each other (any The - is to specify justification, number of columns will of course this is in addherence to std work) independantly word-wrapped, sprintf which defaults to can be useful. right-justification, this version also supports centre and right justification. (7) Result: 426 > write("%-$*s\n", screen_width, >> "Given a\nlist of\nslosh-n\nseparated\n'words',\nthis option\n"+ >> "creates a\ntable out\nof them\nthe number of\ncolumns\n"+ >> "be forced\nby specifying a\npresision.\nThe most obvious\n"+ >> "use is for\nformatted\nls output."); Given a list of slosh-n separated 'words', this option creates a table out of them the number of columns be forced by specifying a presision. The most obvious use is for formatted ls output. (8) Result: 312 > write("%-#*s\n", screen_width, >> "Given a\nlist of\nslosh-n\nseparated\n'words',\nthis option\n"+ >> "creates a\ntable out\nof them\nthe number of\ncolumns\n"+ >> "be forced\nby specifying a\npresision.\nThe most obvious\n"+ >> "use is for\nformatted\nls output."); Given a creates a by specifying a list of table out presision. slosh-n of them The most obvious separated the number of use is for 'words', columns formatted this option be forced ls output. (9) Result: 312 > sample = ([ "align":"left", "valign":"middle" ]); (10) Result: ([ /* 2 elements */ "align":"left", "valign":"middle" ]) > write("<td%{ %s='%s'%}>\n", (array)sample); <td valign='middle' align='left'> (11) Result: 34 > write("Of course all the simple printf options "+ >> "are supported:\n %s: %d %x %o %c\n", >> "65 as decimal, hex, octal and a char", >> 65, 65, 65, 65); Of course all the simple printf options are supported: 65 as decimal, hex, octal and a char: 65 41 101 A (12) Result: 106 > write("%[0]d, %[0]x, %[0]X, %[0]o, %[0]c\n", 75); 75, 4b, 4B, 113, K (13) Result: 19 > write("%|*s\n",screen_width, "THE END"); THE END (14) Result: 71

See also

lfun::_sprintf()