Source file src/cmd/vendor/golang.org/x/sys/windows/exec_windows.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	// Fork, exec, wait, etc.
     6	
     7	package 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.
    18	func 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	
    76	func CloseOnExec(fd Handle) {
    77		SetHandleInformation(Handle(fd), HANDLE_FLAG_INHERIT, 0)
    78	}
    79	
    80	// FullPath retrieves the full path of the specified file.
    81	func 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	

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