diff options
Diffstat (limited to 'README.EXT')
| -rw-r--r-- | README.EXT | 1009 |
1 files changed, 0 insertions, 1009 deletions
diff --git a/README.EXT b/README.EXT deleted file mode 100644 index 12d379e09b..0000000000 --- a/README.EXT +++ /dev/null @@ -1,1009 +0,0 @@ -.\" README.EXT - -*- Text -*- created at: Mon Aug 7 16:45:54 JST 1995 - -This document explains how to make extension libraries for Ruby. - -1. Basic knowledge - -In C, variables have types and data do not have types. In contrast, -Ruby variables do not have static type and data themselves have -types. So, data need to be converted across the languages. - -Data in Ruby represented C type `VALUE'. Each VALUE data have its -data-type. - -To retrieve an C data from the VALUE, you need to: - - (1) Identify VALUE's data type - (2) Convert VALUE into C data - -Converting to wrong data type may cause serious problems. - - -1.1 Data-types - -Ruby interpreter has data-types as below: - - T_NIL nil - T_OBJECT ordinary object - T_CLASS class - T_MODULE module - T_FLOAT floating point number - T_STRING string - T_REGEXP regular expression - T_ARRAY array - T_FIXNUM Fixnum(31bit integer) - T_HASH associative array - T_STRUCT (Ruby) structure - T_BIGNUM multi precision integer - T_TRUE true - T_FALSE false - T_DATA data - -Otherwise, there are several other types used internally: - - T_ICLASS - T_MATCH - T_VARMAP - T_SCOPE - T_NODE - -Most of the types are represented by C structures. - -1.2 Check Data Type of the VALUE - -The macro TYPE() defined in ruby.h shows data-type of the VALUE. -TYPE() returns the constant number T_XXXX described above. To handle -data-types, the code will be like: - - switch (TYPE(obj)) { - case T_FIXNUM: - /* process Fixnum */ - break; - case T_STRING: - /* process String */ - break; - case T_ARRAY: - /* process Array */ - break; - default: - /* raise exception */ - rb_raise(rb_eTypeError, "not valid value"); - break; - } - -There is the data-type check function. - - void Check_Type(VALUE value, int type) - -It raises an exception, if the VALUE does not have the type specified. - -There are faster check-macros for fixnums and nil. - - FIXNUM_P(obj) - NIL_P(obj) - -1.3 Convert VALUE into C data - -The data for type T_NIL, T_FALSE, T_TRUE are nil, true, false -respectively. They are singletons for the data type. - -The T_FIXNUM data is the 31bit length fixed integer (63bit length on -some machines), which can be convert to the C integer by using -FIX2INT() macro. There also be NUM2INT() which converts any Ruby -numbers into C integer. The NUM2INT() macro includes type check, so -the exception will be raised if conversion failed. - -Other data types have corresponding C structures, e.g. struct RArray -for T_ARRAY etc. VALUE of the type which has corresponding structure -can be cast to retrieve the pointer to the struct. The casting macro -RXXXX for each data type like RARRAY(obj). see "ruby.h". - -For example, `RSTRING(size)->len' is the way to get the size of the -Ruby String object. The allocated region can be accessed by -`RSTRING(str)->ptr'. For arrays, `RARRAY(ary)->len' and -`RARRAY(ary)->ptr' respectively. - -Notice: Do not change the value of the structure directly, unless you -are responsible about the result. It will be the cause of interesting -bugs. - -1.4 Convert C data into VALUE - -To convert C data to the values of Ruby: - - * FIXNUM - - left shift 1 bit, and turn on LSB. - - * Other pointer values - - cast to VALUE. - -You can determine whether VALUE is pointer or not, by checking LSB. - -Notice Ruby does not allow arbitrary pointer value to be VALUE. They -should be pointers to the structures which Ruby knows. The known -structures are defined in <ruby.h>. - -To convert C numbers to Ruby value, use these macros. - - INT2FIX() for integers within 31bits. - INT2NUM() for arbitrary sized integer. - -INT2NUM() converts integers into Bignums, if it is out of FIXNUM -range, but bit slower. - -1.5 Manipulate Ruby data - -As I already told, it is not recommended to modify object's internal -structure. To manipulate objects, use functions supplied by Ruby -interpreter. Useful functions are listed below (not all): - - String functions - - rb_str_new(char *ptr, int len) - - Creates a new Ruby string. - - rb_str_new2(char *ptr) - - Creates a new Ruby string from C string. This is equivalent to - rb_str_new(ptr, strlen(ptr)). - - rb_tainted_str_new(char *ptr, int len) - - Creates a new tainted Ruby string. Strings from external data - should be tainted. - - rb_tainted_str_new2(char *ptr) - - Creates a new tainted Ruby string from C string. - - rb_str_cat(VALUE str, char *ptr, int len) - - Appends len bytes data from ptr to the Ruby string. - - Array functions - - rb_ary_new() - - Creates an array with no element. - - rb_ary_new2(int len) - - Creates an array with no element, with allocating internal buffer - for len elements. - - rb_ary_new3(int n, ...) - - Creates an n-elements array from arguments. - - rb_ary_new4(int n, VALUE *elts) - - Creates an n-elements array from C array. - - rb_ary_push(VALUE ary, VALUE val) - rb_ary_pop(VALUE ary) - rb_ary_shift(VALUE ary) - rb_ary_unshift(VALUE ary, VALUE val) - rb_ary_entry(VALUE ary, int idx) - - Array operations. The first argument to each functions must be an - array. They may dump core if other types given. - -2. Extend Ruby with C - -2.1 Add new features to Ruby - -You can add new features (classes, methods, etc.) to the Ruby -interpreter. Ruby provides the API to define things below: - - * Classes, Modules - * Methods, Singleton Methods - * Constants - -2.1.1 Class/module definition - -To define class or module, use functions below: - - VALUE rb_define_class(char *name, VALUE super) - VALUE rb_define_module(char *name) - -These functions return the newly created class or module. You may -want to save this reference into the variable to use later. - -To define nested class or module, use functions below: - - VALUE rb_define_class_under(VALUE outer, char *name, VALUE super) - VALUE rb_define_module_under(VALUE outer, char *name) - -2.1.2 Method/singleton method definition - -To define methods or singleton methods, use functions below: - - void rb_define_method(VALUE klass, char *name, - VALUE (*func)(), int argc) - - void rb_define_singleton_method(VALUE object, char *name, - VALUE (*func)(), int argc) - -The `argc' represents the number of the arguments to the C function, -which must be less than 17. But I believe you don't need that much. :-) - -If `argc' is negative, it specifies calling sequence, not number of -the arguments. - -If argc is -1, the function will be called like: - - VALUE func(int argc, VALUE *argv, VALUE obj) - -where argc is the actual number of arguments, argv is the C array of -the arguments, and obj is the receiver. - -if argc is -2, the arguments are passed in Ruby array. The function -will be called like: - - VALUE func(VALUE obj, VALUE args) - -where obj is the receiver, and args is the Ruby array containing -actual arguments. - -There're two more functions to define method. One is to define -private method: - - void rb_define_private_method(VALUE klass, char *name, - VALUE (*func)(), int argc) - -The other is to define module function, which is private AND singleton -method of the module. For example, sqrt is the module function -defined in Math module. It can be call in the form like: - - Math.sqrt(4) - -or - - include Math - sqrt(4) - -To define module function - - void rb_define_module_function(VALUE module, char *name, - VALUE (*func)(), int argc) - -Oh, in addition, function-like method, which is private method defined -in Kernel module, can be defined using: - - void rb_define_global_function(char *name, VALUE (*func)(), int argc) - -To define alias to the method, - - void rb_define_alias(VALUE module, const char* new, const char* old); - -2.1.3 Constant definition - -We have 2 functions to define constants: - - void rb_define_const(VALUE klass, char *name, VALUE val) - void rb_define_global_const(char *name, VALUE val) - -The former is to define constant under specified class/module. The -latter is to define global constant. - -2.2 Use Ruby features from C - -There are several ways to invoke Ruby's features from C code. - -2.2.1 Evaluate Ruby Program in String - -Easiest way to call Ruby's function from C program is to evaluate the -string as Ruby program. This function will do the job. - - VALUE rb_eval_string(char *str) - -Evaluation is done under current context, thus current local variables -of the innermost method (which is defined by Ruby) can be accessed. - -2.2.2 ID or Symbol - -You can invoke methods directly, without parsing the string. First I -need to explain about symbols (which data type is ID). ID is the -integer number to represent Ruby's identifiers such as variable names. -It can be accessed from Ruby in the form like: - - :Identifier - -You can get the symbol value from string within C code, by using - - rb_intern(char *name) - -In addition, the symbols for one character operators (e.g +) is the -code for that character. - -2.2.3 Invoke Ruby method from C - -To invoke methods directly, you can use the function below - - VALUE rb_funcall(VALUE recv, ID mid, int argc, ...) - -This function invokes the method of the recv, which name is specified -by the symbol mid. - -2.2.4 Accessing the variables and constants - -You can access class variables, and instance variables using access -functions. Also, global variables can be shared between both worlds. -There's no way to access Ruby's local variables. - -The functions to access/modify instance variables are below: - - VALUE rb_ivar_get(VALUE obj, ID id) - VALUE rb_ivar_set(VALUE obj, ID id, VALUE val) - -id must be the symbol, which can be retrieved by rb_intern(). - -To access the constants of the class/module: - - VALUE rb_const_get(VALUE obj, ID id) - -See 2.1.3 for defining new constant. - -3. Information sharing between Ruby and C - -3.1 Ruby constant that C can be accessed from C - -Following Ruby constants can be referred from C. - - Qtrue - Qfalse - -Boolean values. Qfalse is false in the C also (i.e. 0). - - Qnil - -Ruby nil in C scope. - -3.2 Global variables shared between C and Ruby - -Information can be shared between two worlds, using shared global -variables. To define them, you can use functions listed below: - - void rb_define_variable(char *name, VALUE *var) - -This function defines the variable which is shared by the both world. -The value of the global variable pointed by `var', can be accessed -through Ruby's global variable named `name'. - -You can define read-only (from Ruby, of course) variable by the -function below. - - void rb_define_readonly_variable(char *name, VALUE *var) - -You can defined hooked variables. The accessor functions (getter and -setter) are called on access to the hooked variables. - - void rb_define_hooked_variable(char *name, VALUE *var, - VALUE (*getter)(), VALUE (*setter)()) - -If you need to supply either setter or getter, just supply 0 for the -hook you don't need. If both hooks are 0, rb_define_hooked_variable() -works just like rb_define_variable(). - - void rb_define_virtual_variable(char *name, - VALUE (*getter)(), VALUE (*setter)()) - -This function defines the Ruby global variable without corresponding C -variable. The value of the variable will be set/get only by hooks. - -The prototypes of the getter and setter functions are as following: - - (*getter)(ID id, void *data, struct global_entry* entry); - (*setter)(VALUE val, ID id, void *data, struct global_entry* entry); - -3.3 Encapsulate C data into Ruby object - -To wrapping and objectify the C pointer as Ruby object (so called -DATA), use Data_Wrap_Struct(). - - Data_Wrap_Struct(klass, mark, free, ptr) - -Data_Wrap_Struct() returns a created DATA object. The klass argument -is the class for the DATA object. The mark argument is the function -to mark Ruby objects pointed by this data. The free argument is the -function to free the pointer allocation. The functions, mark and -free, will be called from garbage collector. - -You can allocate and wrap the structure in one step. - - Data_Make_Struct(klass, type, mark, free, sval) - -This macro returns an allocated Data object, wrapping the pointer to -the structure, which is also allocated. This macro works like: - - (sval = ALLOC(type), Data_Wrap_Struct(klass, mark, free, sval)) - -Arguments, klass, mark, free, works like their counterpart of -Data_Wrap_Struct(). The pointer to allocated structure will be -assigned to sval, which should be the pointer to the type specified. - -To retrieve the C pointer from the Data object, use the macro -Data_Get_Struct(). - - Data_Get_Struct(obj, type, sval) - -The pointer to the structure will be assigned to the variable sval. - -See example below for detail. - -4. Example - Creating dbm extension - -OK, here's the example to make extension library. This is the -extension to access dbm. The full source is included in ext/ -directory in the Ruby's source tree. - -(1) make the directory - - % mkdir ext/dbm - -Make a directory for the extension library under ext directory. - -(2) create MANIFEST file - - % cd ext/dbm - % touch MANIFEST - -There should be MANIFEST file in the directory for the extension -library. Make empty file now. - -(3) design the library - -You need to design the library features, before making it. - -(4) write C code. - -You need to write C code for your extension library. If your library -has only one source file, choosing ``LIBRARY.c'' as a file name is -preferred. On the other hand, in case your library has plural source -files, avoid choosing ``LIBRARY.c'' for a file name. It may conflict -with intermediate file ``LIBRARY.o'' on some platforms. - -Ruby will execute the initializing function named ``Init_LIBRARY'' in -the library. For example, ``Init_dbm()'' will be executed when loading -the library. - -Here's the example of an initializing function. - --- -Init_dbm() -{ - /* define DBM class */ - cDBM = rb_define_class("DBM", rb_cObject); - /* DBM includes Enumerate module */ - rb_include_module(cDBM, rb_mEnumerable); - - /* DBM has class method open(): arguments are received as C array */ - rb_define_singleton_method(cDBM, "open", fdbm_s_open, -1); - - /* DBM instance method close(): no args */ - rb_define_method(cDBM, "close", fdbm_close, 0); - /* DBM instance method []: 1 argument */ - rb_define_method(cDBM, "[]", fdbm_fetch, 1); - : - -} --- - -The dbm extension wrap dbm struct in C world using Data_Make_Struct. - --- -struct dbmdata { - int di_size; - DBM *di_dbm; -}; - - -obj = Data_Make_Struct(klass, struct dbmdata, 0, free_dbm, dbmp); --- - -This code wraps dbmdata structure into Ruby object. We avoid wrapping -DBM* directly, because we want to cache size information. - -To retrieve dbmdata structure from Ruby object, we define the macro below: - --- -#define GetDBM(obj, dbmp) {\ - Data_Get_Struct(obj, struct dbmdata, dbmp);\ - if (dbmp->di_dbm == 0) closed_dbm();\ -} --- - -This sort of complicated macro do the retrieving and close check for -the DBM. - -There are three kind of way to receiving method arguments. First, the -methods with fixed number of arguments receives arguments like this: - --- -static VALUE -fdbm_delete(obj, keystr) - VALUE obj, keystr; -{ - : -} --- - -The first argument of the C function is the self, the rest are the -arguments to the method. - -Second, the methods with arbitrary number of arguments receives -arguments like this: - --- -static VALUE -fdbm_s_open(argc, argv, klass) - int argc; - VALUE *argv; - VALUE klass; -{ - : - if (rb_scan_args(argc, argv, "11", &file, &vmode) == 1) { - mode = 0666; /* default value */ - } - : -} --- - -The first argument is the number of method arguments. the second -argument is the C array of the method arguments. And the third -argument is the receiver of the method. - -You can use the function rb_scan_args() to check and retrieve the -arguments. For example "11" means, the method requires at least one -argument, and at most receives two arguments. - -The methods with arbitrary number of arguments can receives arguments -by Ruby's array, like this: - --- -static VALUE -fdbm_indexes(obj, args) - VALUE obj, args; -{ - : -} --- - -The first argument is the receiver, the second one is the Ruby array -which contains the arguments to the method. - -** Notice - -GC should know about global variables which refers Ruby's objects, but -not exported to the Ruby world. You need to protect them by - - void rb_global_variable(VALUE *var) - -(5) prepare extconf.rb - -If there exists the file named extconf.rb, it will be executed to -generate Makefile. If not, compilation scheme try to generate -Makefile anyway. - -The extconf.rb is the file to check compilation condition etc. You -need to put - - require 'mkmf' - -at the top of the file. You can use the functions below to check the -condition. - - have_library(lib, func): check whether library containing function exists. - have_func(func, header): check whether function exists - have_header(header): check whether header file exists - create_makefile(target): generate Makefile - -The value of variables below will affect Makefile. - - $CFLAGS: included in CFLAGS make variable (such as -I) - $LDFLAGS: included in LDFLAGS make variable (such as -L) - -If compilation condition is not fulfilled, you do not call -``create_makefile''. Makefile will not generated, compilation will -not be done. - -(6) prepare depend (optional) - -If the file named depend exists, Makefile will include that file to -check dependency. You can make this file by invoking - - % gcc -MM *.c > depend - -It's no harm. Prepare it. - -(7) put file names into MANIFEST (optional) - - % find * -type f -print > MANIFEST - % vi MANIFEST - -Append file names into MANIFEST. The compilation scheme requires -MANIFEST only to be exist. But, you'd better take this step to -distinguish required files. - -(8) generate Makefile - -Try generate Makefile by: - - ruby extconf.rb - -You don't need this step, if you put extension library under ext -directory of the ruby source tree. In that case, compilation of the -interpreter will do this step for you. - -(9) make - -Type - - make - -to compile your extension. You don't need this step neither, if you -put extension library under ext directory of the ruby source tree. - -(9) debug - -You may need to rb_debug the extension. The extensions can be linked -statically by adding directory name in the ext/Setup file, so that you -can inspect the extension with the debugger. - -(10) done, now you have the extension library - -You can do anything you want with your library. The author of Ruby -will not claim any restriction about your code depending Ruby API. -Feel free to use, modify, distribute or sell your program. - -Appendix A. Ruby source files overview - -ruby language core - - class.c - error.c - eval.c - gc.c - object.c - parse.y - variable.c - -utility functions - - dln.c - regex.c - st.c - util.c - -ruby interpreter implementation - - dmyext.c - inits.c - main.c - ruby.c - version.c - -class library - - array.c - bignum.c - compar.c - dir.c - enum.c - file.c - hash.c - io.c - marshal.c - math.c - numeric.c - pack.c - prec.c - process.c - random.c - range.c - re.c - signal.c - sprintf.c - string.c - struct.c - time.c - -Appendix B. Ruby extension API reference - -** Types - - VALUE - -The type for Ruby object. Actual structures are defined in ruby.h, -such as struct RString, etc. To refer the values in structures, use -casting macros like RSTRING(obj). - -** Variables and constants - - Qnil - -const: nil object - - Qtrue - -const: true object(default true value) - - Qfalse - -const: false object - -** C pointer wrapping - - Data_Wrap_Struct(VALUE klass, void (*mark)(), void (*free)(), void *sval) - -Wrap C pointer into Ruby object. If object has references to other -Ruby object, they should be marked by using mark function during GC -process. Otherwise, mark should be 0. When this object is no longer -referred by anywhere, the pointer will be discarded by free function. - - Data_Make_Struct(klass, type, mark, free, sval) - -This macro allocates memory using malloc(), assigns it to the variable -sval, and returns the DATA encapsulating the pointer to memory region. - - Data_Get_Struct(data, type, sval) - -This macro retrieves the pointer value from DATA, and assigns it to -the variable sval. - -** defining class/module - - VALUE rb_define_class(char *name, VALUE super) - -Defines new Ruby class as subclass of super. - - VALUE rb_define_class_under(VALUE module, char *name, VALUE super) - -Creates new Ruby class as subclass of super, under the module's -namespace. - - VALUE rb_define_module(char *name) - -Defines new Ruby module. - - VALUE rb_define_module_under(VALUE module, char *name, VALUE super) - -Defines new Ruby module, under the module's namespace. - - void rb_include_module(VALUE klass, VALUE module) - -Includes module into class. If class already includes it, just -ignore. - - void rb_extend_object(VALUE object, VALUE module) - -Extend the object with module's attribute. - -** Defining Global Variables - - void rb_define_variable(char *name, VALUE *var) - -Defines a global variable which is shared between C and Ruby. If name -contains the character which is not allowed to be part of the symbol, -it can't be seen from Ruby programs. - - void rb_define_readonly_variable(char *name, VALUE *var) - -Defines a read-only global variable. Works just like -rb_define_variable(), except defined variable is read-only. - - void rb_define_virtual_variable(char *name, - VALUE (*getter)(), VALUE (*setter)()) - -Defines a virtual variable, whose behavior is defined by pair of C -functions. The getter function is called when the variable is -referred. The setter function is called when the value is set to the -variable. The prototype for getter/setter functions are: - - VALUE getter(ID id) - void setter(VALUE val, ID id) - -The getter function must return the value for the access. - - void rb_define_hooked_variable(char *name, VALUE *var, - VALUE (*getter)(), VALUE (*setter)()) - -Defines hooked variable. It's virtual variable with C variable. The -getter is called as - - VALUE getter(ID id, VALUE *var) - -returning new value. The setter is called as - - void setter(VALUE val, ID id, VALUE *var) - -GC requires to mark the C global variables which hold Ruby values. - - void rb_global_variable(VALUE *var) - -Tells GC to protect these variables. - -** Constant Definition - - void rb_define_const(VALUE klass, char *name, VALUE val) - -Defines a new constant under the class/module. - - void rb_define_global_const(char *name, VALUE val) - -Defines global constant. This is just work as - - rb_define_const(cKernal, name, val) - -** Method Definition - - rb_define_method(VALUE klass, char *name, VALUE (*func)(), int argc) - -Defines a method for the class. func is the function pointer. argc -is the number of arguments. if argc is -1, the function will receive -3 arguments argc, argv, and self. if argc is -2, the function will -receive 2 arguments, self and args, where args is the Ruby array of -the method arguments. - - rb_define_private_method(VALUE klass, char *name, VALUE (*func)(), int argc) - -Defines a private method for the class. Arguments are same as -rb_define_method(). - - rb_define_singleton_method(VALUE klass, char *name, VALUE (*func)(), int argc) - -Defines a singleton method. Arguments are same as rb_define_method(). - - rb_scan_args(int argc, VALUE *argv, char *fmt, ...) - -Retrieve argument from argc, argv. The fmt is the format string for -the arguments, such as "12" for 1 non-optional argument, 2 optional -arguments. If `*' appears at the end of fmt, it means the rest of -the arguments are assigned to corresponding variable, packed in -array. - -** Invoking Ruby method - - VALUE rb_funcall(VALUE recv, ID mid, int narg, ...) - -Invokes the method. To retrieve mid from method name, use rb_intern(). - - VALUE rb_funcall2(VALUE recv, ID mid, int argc, VALUE *argv) - -Invokes method, passing arguments by array of values. - - VALUE rb_eval_string(char *str) - -Compiles and executes the string as Ruby program. - - ID rb_intern(char *name) - -Returns ID corresponding the name. - - char *rb_id2name(ID id) - -Returns the name corresponding ID. - - char *rb_class2name(VALUE klass) - -Returns the name of the class. - - int rb_respond_to(VALUE object, ID id) - -Returns true if the object responds to the message specified by id. - -** Instance Variables - - VALUE rb_iv_get(VALUE obj, char *name) - -Retrieve the value of the instance variable. If the name is not -prefixed by `@', that variable shall be inaccessible from Ruby. - - VALUE rb_iv_set(VALUE obj, char *name, VALUE val) - -Sets the value of the instance variable. - -** Control Structure - - VALUE rb_iterate(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2) - -Calls the function func1, supplying func2 as the block. func1 will be -called with the argument arg1. func2 receives the value from yield as -the first argument, arg2 as the second argument. - - VALUE rb_yield(VALUE val) - -Evaluates the block with value val. - - VALUE rb_rescue(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2) - -Calls the function func1, with arg1 as the argument. If exception -occurs during func1, it calls func2 with arg2 as the argument. The -return value of rb_rescue() is the return value from func1 if no -exception occurs, from func2 otherwise. - - VALUE rb_ensure(VALUE (*func1)(), void *arg1, void (*func2)(), void *arg2) - -Calls the function func1 with arg1 as the argument, then calls func2 -with arg2, whenever execution terminated. The return value from -rb_ensure() is that of func1. - -** Exceptions and Errors - - void rb_warn(char *fmt, ...) - -Prints warning message according to the printf-like format. - - void rb_warning(char *fmt, ...) - -Prints warning message according to the printf-like format, if -$VERBOSE is true. - - void rb_raise(VALUE exception, char *fmt, ...) - -Raises an exception of class exception. The fmt is the format string -just like printf(). - - void rb_fatal(char *fmt, ...) - -Raises fatal error, terminates the interpreter. No exception handling -will be done for fatal error, but ensure blocks will be executed. - - void rb_bug(char *fmt, ...) - -Terminates the interpreter immediately. This function should be -called under the situation caused by the bug in the interpreter. No -exception handling nor ensure execution will be done. - -** Initialize and Starts the Interpreter - -The embedding API are below (not needed for extension libraries): - - void ruby_init() - -Initializes the interpreter. - - void ruby_options(int argc, char **argv) - -Process command line arguments for the interpreter. - - void ruby_run() - -Starts execution of the interpreter. - - void ruby_script(char *name) - -Specifies the name of the script ($0). - -Appendix B. Functions Available in extconf.rb - -These functions are available in extconf.rb: - - have_library(lib, func) - -Checks whether library which contains specified function exists. -Returns true if the library exists. - - have_func(func, header) - -Checks whether func exists with header. Returns true if the function -exists. To check functions in the additional library, you need to -check that library first using have_library(). - - have_header(header) - -Checks for the header files. Returns true if the header file exists. - - create_makefile(target) - -Generates the Makefile for the extension library. If you don't invoke -this method, the compilation will not be done. - -/* - * Local variables: - * fill-column: 70 - * end: - */ |