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// Fork, exec, wait, etc.
6
7package windows
8
9// EscapeArg rewrites command line argument s as prescribed
10// in http://msdn.microsoft.com/en-us/library/ms880421.
11// This function returns "" (2 double quotes) if s is empty.
12// Alternatively, these transformations are done:
13// - every back slash (\) is doubled, but only if immediately
14//   followed by double quote (");
15// - every double quote (") is escaped by back slash (\);
16// - finally, s is wrapped with double quotes (arg -> "arg"),
17//   but only if there is space or tab inside s.
18func EscapeArg(s string) string {
19	if len(s) == 0 {
20		return "\"\""
21	}
22	n := len(s)
23	hasSpace := false
24	for i := 0; i < len(s); i++ {
25		switch s[i] {
26		case '"', '\\':
27			n++
28		case ' ', '\t':
29			hasSpace = true
30		}
31	}
32	if hasSpace {
33		n += 2
34	}
35	if n == len(s) {
36		return s
37	}
38
39	qs := make([]byte, n)
40	j := 0
41	if hasSpace {
42		qs[j] = '"'
43		j++
44	}
45	slashes := 0
46	for i := 0; i < len(s); i++ {
47		switch s[i] {
48		default:
49			slashes = 0
50			qs[j] = s[i]
51		case '\\':
52			slashes++
53			qs[j] = s[i]
54		case '"':
55			for ; slashes > 0; slashes-- {
56				qs[j] = '\\'
57				j++
58			}
59			qs[j] = '\\'
60			j++
61			qs[j] = s[i]
62		}
63		j++
64	}
65	if hasSpace {
66		for ; slashes > 0; slashes-- {
67			qs[j] = '\\'
68			j++
69		}
70		qs[j] = '"'
71		j++
72	}
73	return string(qs[:j])
74}
75
76func CloseOnExec(fd Handle) {
77	SetHandleInformation(Handle(fd), HANDLE_FLAG_INHERIT, 0)
78}
79
80// FullPath retrieves the full path of the specified file.
81func FullPath(name string) (path string, err error) {
82	p, err := UTF16PtrFromString(name)
83	if err != nil {
84		return "", err
85	}
86	n := uint32(100)
87	for {
88		buf := make([]uint16, n)
89		n, err = GetFullPathName(p, uint32(len(buf)), &buf[0], nil)
90		if err != nil {
91			return "", err
92		}
93		if n <= uint32(len(buf)) {
94			return UTF16ToString(buf[:n]), nil
95		}
96	}
97}
98