{
    "mode": "perldoc",
    "parameter": "bigint",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/perldoc/bigint/json",
    "generated": "2026-06-11T06:52:41Z",
    "synopsis": "use bigint;\n$x = 2 + 4.5,\"\\n\";                    # BigInt 6\nprint 2  512,\"\\n\";                  # really is what you think it is\nprint inf + 42,\"\\n\";                  # inf\nprint NaN * 7,\"\\n\";                   # NaN\nprint hex(\"0x1234567890123490\"),\"\\n\"; # Perl v5.10.0 or later\n{\nno bigint;\nprint 2  256,\"\\n\";                # a normal Perl scalar now\n}\n# Import into current package:\nuse bigint qw/hex oct/;\nprint hex(\"0x1234567890123490\"),\"\\n\";\nprint oct(\"01234567890123490\"),\"\\n\";",
    "sections": {
        "NAME": {
            "content": "bigint - Transparent BigInteger support for Perl\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "use bigint;\n\n$x = 2 + 4.5,\"\\n\";                    # BigInt 6\nprint 2  512,\"\\n\";                  # really is what you think it is\nprint inf + 42,\"\\n\";                  # inf\nprint NaN * 7,\"\\n\";                   # NaN\nprint hex(\"0x1234567890123490\"),\"\\n\"; # Perl v5.10.0 or later\n\n{\nno bigint;\nprint 2  256,\"\\n\";                # a normal Perl scalar now\n}\n\n# Import into current package:\nuse bigint qw/hex oct/;\nprint hex(\"0x1234567890123490\"),\"\\n\";\nprint oct(\"01234567890123490\"),\"\\n\";\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "All operators (including basic math operations) except the range operator \"..\" are overloaded.\nInteger constants are created as proper BigInts.\n\nFloating point constants are truncated to integer. All parts and results of expressions are also\ntruncated.\n\nUnlike integer, this pragma creates integer constants that are only limited in their size by the\navailable memory and CPU time.\n\nuse integer vs. use bigint\nThere is one small difference between \"use integer\" and \"use bigint\": the former will not affect\nassignments to variables and the return value of some functions. \"bigint\" truncates these\nresults to integer too:\n\n# perl -Minteger -wle 'print 3.2'\n3.2\n# perl -Minteger -wle 'print 3.2 + 0'\n3\n# perl -Mbigint -wle 'print 3.2'\n3\n# perl -Mbigint -wle 'print 3.2 + 0'\n3\n\n# perl -Mbigint -wle 'print exp(1) + 0'\n2\n# perl -Mbigint -wle 'print exp(1)'\n2\n# perl -Minteger -wle 'print exp(1)'\n2.71828182845905\n# perl -Minteger -wle 'print exp(1) + 0'\n2\n\nIn practice this makes seldom a difference as parts and results of expressions will be truncated\nanyway, but this can, for instance, affect the return value of subroutines:\n\nsub threeinteger { use integer; return 3.2; }\nsub threebigint { use bigint; return 3.2; }\n\nprint threeinteger(), \" \", threebigint(),\"\\n\";    # prints \"3.2 3\"\n",
            "subsections": [
                {
                    "name": "Options",
                    "content": "bigint recognizes some options that can be passed while loading it via use. The options can\n(currently) be either a single letter form, or the long form. The following options exist:\n\na or accuracy\nThis sets the accuracy for all math operations. The argument must be greater than or equal to\nzero. See Math::BigInt's bround() function for details.\n\nperl -Mbigint=a,2 -le 'print 12345+1'\n\nNote that setting precision and accuracy at the same time is not possible.\n\np or precision\nThis sets the precision for all math operations. The argument can be any integer. Negative\nvalues mean a fixed number of digits after the dot, and are <B>ignored</B> since all\noperations happen in integer space. A positive value rounds to this digit left from the dot. 0\nor 1 mean round to integer and are ignore like negative values.\n\nSee Math::BigInt's bfround() function for details.\n\nperl -Mbignum=p,5 -le 'print 123456789+123'\n\nNote that setting precision and accuracy at the same time is not possible.\n\nt or trace\nThis enables a trace mode and is primarily for debugging bigint or Math::BigInt.\n\nhex\nOverride the built-in hex() method with a version that can handle big integers. This overrides\nit by exporting it to the current package. Under Perl v5.10.0 and higher, this is not so\nnecessary, as hex() is lexically overridden in the current scope whenever the bigint pragma is\nactive.\n\noct\nOverride the built-in oct() method with a version that can handle big integers. This overrides\nit by exporting it to the current package. Under Perl v5.10.0 and higher, this is not so\nnecessary, as oct() is lexically overridden in the current scope whenever the bigint pragma is\nactive.\n\nl, lib, try or only\nLoad a different math lib, see \"Math Library\".\n\nperl -Mbigint=lib,GMP -e 'print 2  512'\nperl -Mbigint=try,GMP -e 'print 2  512'\nperl -Mbigint=only,GMP -e 'print 2  512'\n\nCurrently there is no way to specify more than one library on the command line. This means the\nfollowing does not work:\n\nperl -Mbignum=l,GMP,Pari -e 'print 2  512'\n\nThis will be hopefully fixed soon ;)\n\nv or version\nThis prints out the name and version of all modules used and then exits.\n\nperl -Mbigint=v\n"
                },
                {
                    "name": "Math Library",
                    "content": "Math with the numbers is done (by default) by a module called Math::BigInt::Calc. This is\nequivalent to saying:\n\nuse bigint lib => 'Calc';\n\nYou can change this by using:\n\nuse bignum lib => 'GMP';\n\nThe following would first try to find Math::BigInt::Foo, then Math::BigInt::Bar, and when this\nalso fails, revert to Math::BigInt::Calc:\n\nuse bigint lib => 'Foo,Math::BigInt::Bar';\n\nUsing \"lib\" warns if none of the specified libraries can be found and Math::BigInt did fall back\nto one of the default libraries. To suppress this warning, use \"try\" instead:\n\nuse bignum try => 'GMP';\n\nIf you want the code to die instead of falling back, use \"only\" instead:\n\nuse bignum only => 'GMP';\n\nPlease see respective module documentation for further details.\n"
                },
                {
                    "name": "Internal Format",
                    "content": "The numbers are stored as objects, and their internals might change at anytime, especially\nbetween math operations. The objects also might belong to different classes, like Math::BigInt,\nor Math::BigInt::Lite. Mixing them together, even with normal scalars is not extraordinary, but\nnormal and expected.\n\nYou should not depend on the internal format, all accesses must go through accessor methods.\nE.g. looking at $x->{sign} is not a good idea since there is no guaranty that the object in\nquestion has such a hash key, nor is a hash underneath at all.\n"
                },
                {
                    "name": "Sign",
                    "content": "The sign is either '+', '-', 'NaN', '+inf' or '-inf'. You can access it with the sign() method.\n\nA sign of 'NaN' is used to represent the result when input arguments are not numbers or as a\nresult of 0/0. '+inf' and '-inf' represent plus respectively minus infinity. You will get '+inf'\nwhen dividing a positive number by 0, and '-inf' when dividing any negative number by 0.\n"
                },
                {
                    "name": "Method calls",
                    "content": "Since all numbers are now objects, you can use all functions that are part of the BigInt API.\nYou can only use the bxxx() notation, and not the fxxx() notation, though.\n\nBut a warning is in order. When using the following to make a copy of a number, only a shallow\ncopy will be made.\n\n$x = 9; $y = $x;\n$x = $y = 7;\n\nUsing the copy or the original with overloaded math is okay, e.g. the following work:\n\n$x = 9; $y = $x;\nprint $x + 1, \" \", $y,\"\\n\";     # prints 10 9\n\nbut calling any method that modifies the number directly will result in both the original and\nthe copy being destroyed:\n\n$x = 9; $y = $x;\nprint $x->badd(1), \" \", $y,\"\\n\";        # prints 10 10\n\n$x = 9; $y = $x;\nprint $x->binc(1), \" \", $y,\"\\n\";        # prints 10 10\n\n$x = 9; $y = $x;\nprint $x->bmul(2), \" \", $y,\"\\n\";        # prints 18 18\n\nUsing methods that do not modify, but test that the contents works:\n\n$x = 9; $y = $x;\n$z = 9 if $x->iszero();                # works fine\n\nSee the documentation about the copy constructor and \"=\" in overload, as well as the\ndocumentation in BigInt for further details.\n"
                },
                {
                    "name": "Methods",
                    "content": ""
                },
                {
                    "name": "inf",
                    "content": "A shortcut to return Math::BigInt->binf(). Useful because Perl does not always handle bareword\n\"inf\" properly.\n\nNaN()\nA shortcut to return Math::BigInt->bnan(). Useful because Perl does not always handle bareword\n\"NaN\" properly.\n\ne\n# perl -Mbigint=e -wle 'print e'\n\nReturns Euler's number \"e\", aka exp(1). Note that under bigint, this is truncated to an\ninteger, and hence simple '2'.\n\nPI\n# perl -Mbigint=PI -wle 'print PI'\n\nReturns PI. Note that under bigint, this is truncated to an integer, and hence simple '3'.\n"
                },
                {
                    "name": "bexp",
                    "content": "bexp($power,$accuracy);\n\nReturns Euler's number \"e\" raised to the appropriate power, to the wanted accuracy.\n\nNote that under bigint, the result is truncated to an integer.\n\nExample:\n\n# perl -Mbigint=bexp -wle 'print bexp(1,80)'\n"
                },
                {
                    "name": "bpi",
                    "content": "bpi($accuracy);\n\nReturns PI to the wanted accuracy. Note that under bigint, this is truncated to an integer,\nand hence simple '3'.\n\nExample:\n\n# perl -Mbigint=bpi -wle 'print bpi(80)'\n"
                },
                {
                    "name": "upgrade",
                    "content": "Return the class that numbers are upgraded to, is in fact returning $Math::BigInt::upgrade.\n"
                },
                {
                    "name": "in_effect",
                    "content": "use bigint;\n\nprint \"in effect\\n\" if bigint::ineffect;       # true\n{\nno bigint;\nprint \"in effect\\n\" if bigint::ineffect;     # false\n}\n\nReturns true or false if \"bigint\" is in effect in the current scope.\n\nThis method only works on Perl v5.9.4 or later.\n"
                }
            ]
        },
        "CAVEATS": {
            "content": "Operator vs literal overloading\n\"bigint\" works by overloading handling of integer and floating point literals, converting them\nto Math::BigInt objects.\n\nThis means that arithmetic involving only string values or string literals will be performed\nusing Perl's built-in operators.\n\nFor example:\n\nuse bignum;\nmy $x = \"900000000000000009\";\nmy $y = \"900000000000000007\";\nprint $x - $y;\n\nwill output 0 on default 32-bit builds, since \"bigint\" never sees the string literals. To\nensure the expression is all treated as \"Math::BigInt\" objects, use a literal number in the\nexpression:\n\nprint +(0+$x) - $y;\n\nranges\nPerl does not allow overloading of ranges, so you can neither safely use ranges with bigint\nendpoints, nor is the iterator variable a bigint.\n\nuse 5.010;\nfor my $i (12..13) {\nfor my $j (20..21) {\nsay $i  $j;  # produces a floating-point number,\n# not a big integer\n}\n}\n",
            "subsections": [
                {
                    "name": "in_effect",
                    "content": "This method only works on Perl v5.9.4 or later.\n"
                },
                {
                    "name": "hex",
                    "content": "\"bigint\" overrides these routines with versions that can also handle big integer values. Under\nPerl prior to version v5.9.4, however, this will not happen unless you specifically ask for it\nwith the two import tags \"hex\" and \"oct\" - and then it will be global and cannot be disabled\ninside a scope with \"no bigint\":\n\nuse bigint qw/hex oct/;\n\nprint hex(\"0x1234567890123456\");\n{\nno bigint;\nprint hex(\"0x1234567890123456\");\n}\n\nThe second call to hex() will warn about a non-portable constant.\n\nCompare this to:\n\nuse bigint;\n\n# will warn only under Perl older than v5.9.4\nprint hex(\"0x1234567890123456\");\n"
                }
            ]
        },
        "MODULES USED": {
            "content": "\"bigint\" is just a thin wrapper around various modules of the Math::BigInt family. Think of it\nas the head of the family, who runs the shop, and orders the others to do the work.\n\nThe following modules are currently used by bigint:\n\nMath::BigInt::Lite      (for speed, and only if it is loadable)\nMath::BigInt\n",
            "subsections": []
        },
        "EXAMPLES": {
            "content": "Some cool command line examples to impress the Python crowd ;) You might want to compare them to\nthe results under -Mbignum or -Mbigrat:\n\nperl -Mbigint -le 'print sqrt(33)'\nperl -Mbigint -le 'print 2*255'\nperl -Mbigint -le 'print 4.5+2*255'\nperl -Mbigint -le 'print 3/7 + 5/7 + 8/3'\nperl -Mbigint -le 'print 123->isodd()'\nperl -Mbigint -le 'print log(2)'\nperl -Mbigint -le 'print 2  0.5'\nperl -Mbigint=a,65 -le 'print 2  0.2'\nperl -Mbignum=a,65,l,GMP -le 'print 7  7777'\n",
            "subsections": []
        },
        "BUGS": {
            "content": "For information about bugs and how to report them, see the BUGS section in the documentation\navailable with the perldoc command.\n\nperldoc bignum\n",
            "subsections": []
        },
        "SUPPORT": {
            "content": "You can find documentation for this module with the perldoc command.\n\nperldoc bigint\n\nFor more information, see the SUPPORT section in the documentation available with the perldoc\ncommand.\n\nperldoc bignum\n",
            "subsections": []
        },
        "LICENSE": {
            "content": "This program is free software; you may redistribute it and/or modify it under the same terms as\nPerl itself.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "bignum and bigrat.\n\nMath::BigInt, Math::BigFloat, Math::BigRat and Math::Big as well as Math::BigInt::FastCalc,\nMath::BigInt::Pari and Math::BigInt::GMP.\n",
            "subsections": []
        },
        "AUTHORS": {
            "content": "*   (C) by Tels <http://bloodgate.com/> in early 2002 - 2007.\n\n*   Maintained by Peter John Acklam <pjacklam@gmail.com<gt>, 2014-.\n",
            "subsections": []
        }
    },
    "summary": "bigint - Transparent BigInteger support for Perl",
    "flags": [],
    "examples": [
        "Some cool command line examples to impress the Python crowd ;) You might want to compare them to",
        "the results under -Mbignum or -Mbigrat:",
        "perl -Mbigint -le 'print sqrt(33)'",
        "perl -Mbigint -le 'print 2*255'",
        "perl -Mbigint -le 'print 4.5+2*255'",
        "perl -Mbigint -le 'print 3/7 + 5/7 + 8/3'",
        "perl -Mbigint -le 'print 123->isodd()'",
        "perl -Mbigint -le 'print log(2)'",
        "perl -Mbigint -le 'print 2  0.5'",
        "perl -Mbigint=a,65 -le 'print 2  0.2'",
        "perl -Mbignum=a,65,l,GMP -le 'print 7  7777'"
    ],
    "see_also": []
}