diff options
Diffstat (limited to 'content/c-go-cgo.article')
| -rw-r--r-- | content/c-go-cgo.article | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/content/c-go-cgo.article b/content/c-go-cgo.article index 71773b9..19a01f3 100644 --- a/content/c-go-cgo.article +++ b/content/c-go-cgo.article @@ -50,7 +50,7 @@ The `Seed` function does the reverse, in a way. It takes a regular Go `int`, con C.srandom(C.uint(i)) } -Note that cgo knows the `unsigned`int` type as `C.uint`; see the [[http://golang.org/cmd/cgo][cgo documentation]] for a complete list of these numeric type names. +Note that cgo knows the `unsigned`int` type as `C.uint`; see the [[https://golang.org/cmd/cgo][cgo documentation]] for a complete list of these numeric type names. The one detail of this example we haven't examined yet is the comment above the `import` statement. @@ -63,7 +63,7 @@ Cgo recognizes this comment. Any lines starting with `#cgo` followed by a space There is a limitation: if your program uses any `//export` directives, then the C code in the comment may only include declarations (`extern`int`f();`), not definitions (`int`f()`{`return`1;`}`). You can use `//export` directives to make Go functions accessible to C code. -The `#cgo` and `//export` directives are documented in the [[http://golang.org/cmd/cgo/][cgo documentation]]. +The `#cgo` and `//export` directives are documented in the [[https://golang.org/cmd/cgo/][cgo documentation]]. * Strings and things @@ -88,7 +88,7 @@ This next example implements a `Print` function that writes a string to standard Memory allocations made by C code are not known to Go's memory manager. When you create a C string with `C.CString` (or any C memory allocation) you must remember to free the memory when you're done with it by calling `C.free`. -The call to `C.CString` returns a pointer to the start of the char array, so before the function exits we convert it to an [[http://golang.org/pkg/unsafe/#Pointer][`unsafe.Pointer`]] and release the memory allocation with `C.free`. A common idiom in cgo programs is to [[http://golang.org/doc/articles/defer_panic_recover.html][`defer`]] the free immediately after allocating (especially when the code that follows is more complex than a single function call), as in this rewrite of `Print`: +The call to `C.CString` returns a pointer to the start of the char array, so before the function exits we convert it to an [[https://golang.org/pkg/unsafe/#Pointer][`unsafe.Pointer`]] and release the memory allocation with `C.free`. A common idiom in cgo programs is to [[https://golang.org/doc/articles/defer_panic_recover.html][`defer`]] the free immediately after allocating (especially when the code that follows is more complex than a single function call), as in this rewrite of `Print`: func Print(s string) { cs := C.CString(s) @@ -98,10 +98,10 @@ The call to `C.CString` returns a pointer to the start of the char array, so bef * Building cgo packages -To build cgo packages, just use [[http://golang.org/cmd/go/#Compile_packages_and_dependencies][`go`build`]] or [[http://golang.org/cmd/go/#Compile_and_install_packages_and_dependencies][`go`install`]] as usual. The go tool recognizes the special `"C"` import and automatically uses cgo for those files. +To build cgo packages, just use [[https://golang.org/cmd/go/#Compile_packages_and_dependencies][`go`build`]] or [[https://golang.org/cmd/go/#Compile_and_install_packages_and_dependencies][`go`install`]] as usual. The go tool recognizes the special `"C"` import and automatically uses cgo for those files. * More cgo resources -The [[http://golang.org/cmd/cgo/][cgo command]] documentation has more detail about the C pseudo-package and the build process. The [[http://golang.org/misc/cgo/][cgo examples]] in the Go tree demonstrate more advanced concepts. +The [[https://golang.org/cmd/cgo/][cgo command]] documentation has more detail about the C pseudo-package and the build process. The [[https://golang.org/misc/cgo/][cgo examples]] in the Go tree demonstrate more advanced concepts. Finally, if you're curious as to how all this works internally, take a look at the introductory comment of the runtime package's [[https://golang.org/src/runtime/cgocall.go][cgocall.go]]. |