NAME printf - formatted print to standard output SYNOPSIS printf(fmt, x_1, x_2, ...) TYPES fmt string x_1, x_2, ... any return null DESCRIPTION The function printf() is similar to the C function with the same name. The most significant difference is that there is no requirement that the types of values of the arguments x_i match the corresponding format specifier in fmt. Thus, whatver the format specifier, a number is printed as a number, a string as a string, a list as a list, a matrix as a matrix, an xx-object as an xx-object, etc. Except when a '%' is encountered, characters of the string fmt are printed in succession to the standard output. Occurrence of a '%' indicates the intention to build a format specifier. This is completed by a succession of characters as follows: an optional '-' zero or more decimal digits an optional '. followed by zero or more decimal deigits an optional 'l' one of the letters: d, s, c, f, e, g, r, o, x, b, If any other character is read, the '%' and any characters between '%' and the character are ignored and no specifier is formed. E.g. "%+f" prints as if only "f" were read; "% 10s" prints as "10s", "%X" prints as "X", "%%" prints as "%". The characters in a format specifier are interpreted as follows: a minus sign sets the right-pad flag; the first group of digits determines the width w; w = 0 if there are no digits a dot indicates the precision is to be read from the following digits; if there is no dot, precision = config("display"). any digits following the . determines the precision p; p = 0 if there are no digits any 'l' before the final letter is ignored the final letter determines the mode as follows: d, s, c current config("mode") f real (decimal, floating point) e exponential g general format (real or exponential) r fractional o octal x hexadecimal b binary If the number of arguments after fmt is less than the number of format specifiers in fmt, the "missing" arguments may be taken to be null values - these contribute nothing to the output; if a positive width w has been specified, the effect is to produce w spaces, e.g., printf("abc%6dxyz") prints "abc xyz". Control charters may be given in fmt by escaping them with the \ character. The following control charter escape sequences are recognized: \a audible bell byte 0x07 in ASCII encoding \b backspace byte 0x08 in ASCII encoding \f form feed byte 0x0c in ASCII encoding \n newline byte 0x0b in ASCII encoding \r return byte 0x0a in ASCII encoding \t tab byte 0x0d in ASCII encoding \v vertical tab byte 0x09 in ASCII encoding If i <= the number of specifiers in fmt, the value of argument x_i is printed in the format specified by the i-th specifier. If a positive width w has been specified and normal printing of x_i does not include a '\n' character, what is printed will if necessary be padded with spaces so that the length of the printed output is at least the w. Note that control characters (e.g., '\a', '\b', '\f', '\n', '\r', '\t', '\n') count as one character. If the 'right-pad' flag has been set, the padding is on the right; otherwise it is on the left. If i > the number of specifiers in fmt, the value of argument x_i does not contribute to the printing. However, as all arguments are evaluated before printing occurs, side-effects of the evaluation of x_i might affect the result. If the i-th specifier is of numerical type, any numbers in the printing of x_i will be printed in the specified format, unless this is modified by the printing procedure for x_i's type. Any specified precision will be ignored except for floating-point mode. The (g) general format will print the as real (f) (decimal or floating point) or as an exponential (e) depending on the configuration parameter "display". In the case of floating-point (f) format, and the (g) general format, the precision determines the maximum number of decimal places to be displayed. Other aspects of this printing may be affected by the configuration parameters "outround", "tilde", "fullzero", "leadzero". EXAMPLE ; config("epsilon", 1e-6),; : config("display", 6),; ; config("tilde", 1),; ; config("outround", 0),; ; config("fullzero", 0),; ; fmt = "%f,%10f,%-10f,%10.4f,%.4f,%.f.\n"; ; a = sqrt(3); ; printf(fmt,a,a,a,a,a,a); 1.732051, 1.732051,1.732051 , ~1.7320,~1.7320,~1. ; config("display", 5),; : config("tilde", 0),; ; printf("%f\n", pi()); 3.1416 ; config("display", 10),; ; printf("%f\n", pi()); 3.141592654 ; config("tilde", 0),; : config("outround",24),; ; config("fullzero", 1),; ; printf(fmt,a,a,a,a,a,a); 1.732051, 1.732051,1.732051 , 1.7321,1.7321,2. ; mat A[4] = {sqrt(2), 3/7, "undefined", null()}; ; printf("%f%r",A,A); mat [4] (4 elements, 4 nonzero): [0] = 1.414214 [1] = .428571 [2] = "undefined" [3] = NULL mat [4] (4 elements, 4 nonzero): [0] = 707107/500000 [1] = 3/7 [2] = "undefined" [3] = NULL ; config("display", 50),; ; printf("%g %g\n%g %g\n", 1e5, 1e49, 1e50, 1e500); 100000 100000000000000000000000000000000000000000000000000 1e50 1e500 ; config("display", 10),; : config("tilde", 0),; ; printf("%f %f %f\n%f %f %f\n", exp(1), exp(2), exp(3), exp(4), exp(5), exp(6)); 2.7182818285 7.3890560989 20.0855369232 54.5981500331 148.4131591026 403.4287934927 ; printf("%e %e %e\n%e %e %e\n", exp(1), exp(2), exp(3), exp(4), exp(5), exp(6)); 2.7182818285 7.3890560989 2.0085536923e1 5.4598150033e1 1.4841315910e2 4.0342879349e2 ; printf("%g %g %g\n%g %g %g\n", exp(1), exp(2), exp(3), exp(4), exp(5), exp(6)); 2.718281828 7.389056099 20.08553692 54.59815003 148.4131591 403.4287935 ; config("display", 10),; ; config("tilde", 0),; ; printf("%f %f %f\n%f %f %f\n", exp(20), exp(21), exp(22), exp(23), exp(24), exp(25)); 485165195.4097902780 1318815734.4832146972 3584912846.1315915617 9744803446.2489026000 26489122129.8434722941 72004899337.3858725242` ; printf("%e %e %e\n%e %e %e\n", exp(20), exp(21), exp(22), exp(23), exp(24), exp(25)); 4.8516519541e8 1.3188157345e9 3.5849128461e9 9.7448034462e9 2.6489122130e10 7.2004899337e10 ; printf("%g %g %g\n%g %g %g\n", exp(20), exp(21), exp(22), exp(23), exp(24), exp(25)); 485165195.4 1318815734 3584912846 9744803446 2.648912213e10 7.200489934e10 ; /* * NOTE: When displaying many digits after the decimal point * be sure to set display(digits) (see 'help display') to * large enough AND to set epsilon(eps) (see 'help epsilon') * small enough (or if the function has a esp argument, * give a eps argument that is small enough) to display * the value correctly. */ ; config("tilde", 1),; ; /* NOTE: display has too few digits and epsilon is not small enough */ ; display(12),; ; printf("%f\n", pi(1e-10)); 3.1415926536 ; epsilon(1e-10),; ; printf("%f\n", pi()); 3.1415926536 ; /* NOTE: display has too few digits yet epsilon is small enough */ ; display(12),; ; printf("%f\n", pi(1e-72)); ~3.141592653590 ; epsilon(1e-72),; ; printf("%f\n", pi()); ~3.141592653590 ; /* NOTE: display has enough digits but epsilon is not small enough */ ; display(72),; ; printf("%f\n", pi(1e-10)); 3.1415926536 ; epsilon(1e-10),; ; printf("%f\n", pi()); 3.1415926536 /* NOTE: display has enough digits and epsilon is small enough */ ; display(72),; ; printf("%f\n", pi(1e-72)); 3.141592653589793238462643383279502884197169399375105820974944592307816406 ; epsilon(1e-72),; ; printf("%f\n", pi()); 3.141592653589793238462643383279502884197169399375105820974944592307816406 LIMITS The number of arguments of printf() is not to exceed 1024. LINK LIBRARY none SEE ALSO config, display, epsilon, fprintf, strprintf ## Copyright (C) 1999-2006,2018 Landon Curt Noll ## ## Calc is open software; you can redistribute it and/or modify it under ## the terms of the version 2.1 of the GNU Lesser General Public License ## as published by the Free Software Foundation. ## ## Calc is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY ## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General ## Public License for more details. ## ## A copy of version 2.1 of the GNU Lesser General Public License is ## distributed with calc under the filename COPYING-LGPL. You should have ## received a copy with calc; if not, write to Free Software Foundation, Inc. ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ## ## Under source code control: 1996/03/12 22:50:41 ## File existed as early as: 1996 ## ## chongo /\oo/\ http://www.isthe.com/chongo/ ## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/