| 1 | // Copyright 2013 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 | package vcs |
| 6 | |
| 7 | import ( |
| 8 | "os" |
| 9 | "strings" |
| 10 | ) |
| 11 | |
| 12 | // envForDir returns a copy of the environment |
| 13 | // suitable for running in the given directory. |
| 14 | // The environment is the current process's environment |
| 15 | // but with an updated $PWD, so that an os.Getwd in the |
| 16 | // child will be faster. |
| 17 | func envForDir(dir string) []string { |
| 18 | env := os.Environ() |
| 19 | // Internally we only use rooted paths, so dir is rooted. |
| 20 | // Even if dir is not rooted, no harm done. |
| 21 | return mergeEnvLists([]string{"PWD=" + dir}, env) |
| 22 | } |
| 23 | |
| 24 | // mergeEnvLists merges the two environment lists such that |
| 25 | // variables with the same name in "in" replace those in "out". |
| 26 | func mergeEnvLists(in, out []string) []string { |
| 27 | NextVar: |
| 28 | for _, inkv := range in { |
| 29 | k := strings.SplitAfterN(inkv, "=", 2)[0] |
| 30 | for i, outkv := range out { |
| 31 | if strings.HasPrefix(outkv, k) { |
| 32 | out[i] = inkv |
| 33 | continue NextVar |
| 34 | } |
| 35 | } |
| 36 | out = append(out, inkv) |
| 37 | } |
| 38 | return out |
| 39 | } |
| 40 |
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