forked from juju/utils
/
setenv.go
32 lines (29 loc) · 821 Bytes
/
setenv.go
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// Copyright 2013 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package utils
import (
"strings"
)
// Setenv sets an environment variable entry in the given env slice (as
// returned by os.Environ or passed in exec.Cmd.Environ) to the given
// value. The entry should be in the form "x=y" where x is the name of the
// environment variable and y is its value; if not, env will be
// returned unchanged.
//
// If a value isn't already present in the slice, the entry is appended.
//
// The new environ slice is returned.
func Setenv(env []string, entry string) []string {
i := strings.Index(entry, "=")
if i == -1 {
return env
}
prefix := entry[0 : i+1]
for i, e := range env {
if strings.HasPrefix(e, prefix) {
env[i] = entry
return env
}
}
return append(env, entry)
}