From b8c6298c421a200fc2b2ea1873784120e86c552c Mon Sep 17 00:00:00 2001 From: Dave Beazley Date: Thu, 31 Aug 2000 04:36:54 +0000 Subject: [PATCH] New example git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@743 626c5289-ae23-0410-ae9c-e8d60b6d4f22 --- Examples/perl5/index.html | 1 + Examples/perl5/variables/Makefile | 18 ++++++ Examples/perl5/variables/example.c | 86 +++++++++++++++++++++++++++++ Examples/perl5/variables/example.h | 6 ++ Examples/perl5/variables/example.i | 44 +++++++++++++++ Examples/perl5/variables/example.pl | 65 ++++++++++++++++++++++ Examples/perl5/variables/index.html | 65 ++++++++++++++++++++++ 7 files changed, 285 insertions(+) create mode 100644 Examples/perl5/variables/Makefile create mode 100644 Examples/perl5/variables/example.c create mode 100644 Examples/perl5/variables/example.h create mode 100644 Examples/perl5/variables/example.i create mode 100644 Examples/perl5/variables/example.pl create mode 100644 Examples/perl5/variables/index.html diff --git a/Examples/perl5/index.html b/Examples/perl5/index.html index 007477ab8..8aa1f4b0e 100644 --- a/Examples/perl5/index.html +++ b/Examples/perl5/index.html @@ -16,6 +16,7 @@ The following examples illustrate the use of SWIG with Perl. be used to wrap a C function and a global variable.
  • constants. This shows how preprocessor macros and certain C declarations are turned into constants. +
  • variables. This example shows how to access C global variables from Perl.

    Compilation Issues

    diff --git a/Examples/perl5/variables/Makefile b/Examples/perl5/variables/Makefile new file mode 100644 index 000000000..e5944f9af --- /dev/null +++ b/Examples/perl5/variables/Makefile @@ -0,0 +1,18 @@ +TOP = ../.. +SWIG = $(TOP)/../swig +SRCS = example.c +TARGET = example +INTERFACE = example.i +SWIGOPT = +all:: + $(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \ + SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' perl5 + +static:: + $(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \ + SWIGOPT='$(SWIGOPT)' TARGET='myperl' INTERFACE='$(INTERFACE)' perl5_static + +clean:: + rm -f *_wrap* *.o core *~ *.so *.pm myperl + +check: all diff --git a/Examples/perl5/variables/example.c b/Examples/perl5/variables/example.c new file mode 100644 index 000000000..37e9feb33 --- /dev/null +++ b/Examples/perl5/variables/example.c @@ -0,0 +1,86 @@ +/* File : example.c */ + +/* I'm a file containing some C global variables */ + +#include +#include +#include "example.h" + +int ivar = 0; +short svar = 0; +long lvar = 0; +unsigned int uivar = 0; +unsigned short usvar = 0; +unsigned long ulvar = 0; +signed char scvar = 0; +unsigned char ucvar = 0; +char cvar = 0; +float fvar = 0; +double dvar = 0; +char *strvar = 0; +const char *cstrvar = 0; +int *iptrvar = 0; +char name[256] = "Dave"; +char path[256] = "/home/beazley"; + + +/* Global variables involving a structure */ +Point *ptptr = 0; +Point pt = { 10, 20 }; + +/* A variable that we will make read-only in the interface */ +int status = 1; + +/* A debugging function to print out their values */ + +void print_vars() { + printf("ivar = %d\n", ivar); + printf("svar = %d\n", svar); + printf("lvar = %ld\n", lvar); + printf("uivar = %u\n", uivar); + printf("usvar = %u\n", usvar); + printf("ulvar = %lu\n", ulvar); + printf("scvar = %d\n", scvar); + printf("ucvar = %u\n", ucvar); + printf("fvar = %g\n", fvar); + printf("dvar = %g\n", dvar); + printf("cvar = %c\n", cvar); + printf("strvar = %s\n", strvar ? strvar : "(null)"); + printf("cstrvar = %s\n", cstrvar ? cstrvar : "(null)"); + printf("iptrvar = %x\n", iptrvar); + printf("name = %s\n", name); + printf("ptptr = %x (%d, %d)\n", ptptr, ptptr ? ptptr->x : 0, ptptr ? ptptr->y : 0); + printf("pt = (%d, %d)\n", pt.x, pt.y); + printf("status = %d\n", status); +} + +/* A function to create an integer (to test iptrvar) */ + +int *new_int(int value) { + int *ip = (int *) malloc(sizeof(int)); + *ip = value; + return ip; +} + +/* A function to create a point */ + +Point *new_Point(int x, int y) { + Point *p = (Point *) malloc(sizeof(Point)); + p->x = x; + p->y = y; + return p; +} + +char * Point_print(Point *p) { + static char buffer[256]; + if (p) { + sprintf(buffer,"(%d,%d)", p->x,p->y); + } else { + sprintf(buffer,"null"); + } + return buffer; +} + +void pt_print() { + printf("(%d, %d)\n", pt.x, pt.y); +} diff --git a/Examples/perl5/variables/example.h b/Examples/perl5/variables/example.h new file mode 100644 index 000000000..0f7e89594 --- /dev/null +++ b/Examples/perl5/variables/example.h @@ -0,0 +1,6 @@ +/* File: example.h */ + +typedef struct { + int x,y; +} Point; + diff --git a/Examples/perl5/variables/example.i b/Examples/perl5/variables/example.i new file mode 100644 index 000000000..d62f973da --- /dev/null +++ b/Examples/perl5/variables/example.i @@ -0,0 +1,44 @@ +/* File : example.i */ +%module example +%{ +#include "example.h" +%} + +/* Some global variable declarations */ +extern int ivar; +extern short svar; +extern long lvar; +extern unsigned int uivar; +extern unsigned short usvar; +extern unsigned long ulvar; +extern signed char scvar; +extern unsigned char ucvar; +extern char cvar; +extern float fvar; +extern double dvar; +extern char *strvar; +extern const char *cstrvar; +extern int *iptrvar; +extern char name[256]; + +extern Point *ptptr; +extern Point pt; + + +/* Some read-only variables */ + +%readonly +extern int status; +extern char path[256]; +%readwrite + +/* Some helper functions to make it easier to test */ +extern void print_vars(); +extern int *new_int(int value); +extern Point *new_Point(int x, int y); +extern char *Point_print(Point *p); +extern void pt_print(); + + + + diff --git a/Examples/perl5/variables/example.pl b/Examples/perl5/variables/example.pl new file mode 100644 index 000000000..e4f2e879f --- /dev/null +++ b/Examples/perl5/variables/example.pl @@ -0,0 +1,65 @@ +# file: example.pl + +use example; + +# Try to set the values of some global variables + +$example::ivar = 42; +$example::svar = -31000; +$example::lvar = 65537; +$example::uivar = 123456; +$example::usvar = 61000; +$example::ulvar = 654321; +$example::scvar = -13; +$example::ucvar = 251; +$example::cvar = "S"; +$example::fvar = 3.14159; +$example::dvar = 2.1828; +$example::strvar = "Hello World"; +$example::cstrvar = "Goodbye"; +$example::iptrvar= example::new_int(37); +$example::ptptr = example::new_Point(37,42); +$example::name = "Bill"; + +# Now print out the values of the variables + +print "Variables (values printed from Python)"; + +print "ivar = $example::ivar\n"; +print "svar = $example::svar\n"; +print "lvar = $example::lvar\n"; +print "uivar = $example::uivar\n"; +print "usvar = $example::usvar\n"; +print "ulvar = $example::ulvar\n"; +print "scvar = $example::scvar\n"; +print "ucvar = $example::ucvar\n"; +print "fvar = $example::fvar\n"; +print "dvar = $example::dvar\n"; +print "cvar = $example::cvar\n"; +print "strvar = $example::strvar\n"; +print "cstrvar = $example::cstrvar\n"; +print "iptrvar = $example::iptrvar\n"; +print "name = $example::name\n"; +print "ptptr = $example::ptptr", example::Point_print($example::ptptr), "\n"; +print "pt = $example::pt", example::Point_print($example::pt), "\n"; + +print "\nVariables (values printed from C)\n"; + +example::print_vars(); + +print "\nI'm going to try and update a structure variable.\n"; + +$example::pt = $example::ptptr; + +print "The new value is "; +example::pt_print(); +print "You should see the value", example::Point_print($example::ptptr), "\n"; + + +print "\nNow I'm going to try and modify some read only variables\n"; + +print " Tring to set 'path'\n"; +$example::path = "Whoa!"; + +print " Trying to set 'status'\n"; +$example::status = 0; diff --git a/Examples/perl5/variables/index.html b/Examples/perl5/variables/index.html new file mode 100644 index 000000000..a278445fe --- /dev/null +++ b/Examples/perl5/variables/index.html @@ -0,0 +1,65 @@ + + +SWIG:Examples:perl5:variables + + + + +SWIG/Examples/perl5/variables/ +
    + +

    Wrapping C Global Variables

    + +$Header$
    + +

    +When a C global variable appears in an interface file, SWIG tries to +wrap it using a technique known as "variable linking." The idea is +pretty simple---we try to create a Perl variable that magically +retrieves or updates the value of the underlying C variable when it is +accessed. Click here to see a SWIG interface with some variable +declarations in it. + +

    Manipulating Variables from Perl

    + +Accessing a C global variable from Perl is easy---just reference it like a normal Perl variable. +Click here to see a script that updates and prints some global variables. + +

    Creating read-only variables

    + +The %readonly and %readwrite directives can be used to +specify a collection of read-only variables. For example: + +
    +
    +%readonly
+int    status;
+double blah;
+...
+%readwrite
+
    +
    + +The %readonly directive remains in effect until it is explicitly disabled +using the %readwrite directive. + + +

    Notes:

    + +
      +
    • When a global variable has the type "char *", SWIG manages it as a character +string. However, whenever the value of such a variable is set from Perl, the old +value is destroyed using free() or delete (the choice of which depends +on whether or not SWIG was run with the -c++ option). +
    • signed char and unsigned char are handled as small 8-bit integers. +
    • String array variables such as 'char name[256]' are managed as Perl strings, but +when setting the value, the result is truncated to the maximum length of the array. Furthermore, the string is assumed to be null-terminated. +
    • When structures and classes are used as global variables, they are mapped into pointers. +Getting the "value" returns a pointer to the global variable. Setting the value of a structure results in a memory copy from a pointer to the global. +
    • Variables are linked using Perl's magic mechanism. Take a look at the Advanced Perl Programming book to +find out more about this feature. +
    + + + +
    \ No newline at end of file