40 lines
1.0 KiB
Go
40 lines
1.0 KiB
Go
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package vcs
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import (
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"os"
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"strings"
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)
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// envForDir returns a copy of the environment
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// suitable for running in the given directory.
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// The environment is the current process's environment
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// but with an updated $PWD, so that an os.Getwd in the
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// child will be faster.
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func envForDir(dir string) []string {
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env := os.Environ()
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// Internally we only use rooted paths, so dir is rooted.
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// Even if dir is not rooted, no harm done.
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return mergeEnvLists([]string{"PWD=" + dir}, env)
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}
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// mergeEnvLists merges the two environment lists such that
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// variables with the same name in "in" replace those in "out".
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func mergeEnvLists(in, out []string) []string {
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NextVar:
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for _, inkv := range in {
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k := strings.SplitAfterN(inkv, "=", 2)[0]
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for i, outkv := range out {
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if strings.HasPrefix(outkv, k) {
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out[i] = inkv
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continue NextVar
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}
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}
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out = append(out, inkv)
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}
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return out
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}
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