file.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  /*
     6  A trivial example of wrapping a C library in Go.
     7  For a more complex example and explanation,
     8  see misc/cgo/gmp/gmp.go.
     9  */
    10  
    11  package stdio
    12  
    13  /*
    14  #include <stdio.h>
    15  #include <stdlib.h>
    16  #include <sys/stat.h>
    17  #include <errno.h>
    18  
    19  char* greeting = "hello, world";
    20  */
    21  import "C"
    22  import "unsafe"
    23  
    24  type File C.FILE
    25  
    26  // Test reference to library symbol.
    27  // Stdout and stderr are too special to be a reliable test.
    28  //var  = C.environ
    29  
    30  func (f *File) WriteString(s string) {
    31  	p := C.CString(s)
    32  	C.fputs(p, (*C.FILE)(f))
    33  	C.free(unsafe.Pointer(p))
    34  	f.Flush()
    35  }
    36  
    37  func (f *File) Flush() {
    38  	C.fflush((*C.FILE)(f))
    39  }
    40  
    41  var Greeting = C.GoString(C.greeting)
    42  var Gbytes = C.GoBytes(unsafe.Pointer(C.greeting), C.int(len(Greeting)))
    43
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