mirror of https://github.com/minio/minio.git
64 lines
1.6 KiB
Go
64 lines
1.6 KiB
Go
/*
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* Mini Object Storage, (C) 2014 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package helpers
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import (
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"bytes"
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"errors"
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"io"
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"os/exec"
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)
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// A simple ExecPipe() pipes exec.Cmd together - somewhat similar to how bash pipes "|" behave.
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// Each command's standard output is connected to the standard input of the next command
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// and the output of the final command is returned
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func ExecPipe(cmds ...*exec.Cmd) (pipeLineOutput io.Reader, pipeLineError error) {
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// Require at least one command
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if len(cmds) < 1 {
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return nil, errors.New("Invalid argument")
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}
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// Collect the output from the command(s)
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var output bytes.Buffer
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lastIndex := len(cmds) - 1
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for i, cmd := range cmds[:lastIndex] {
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cmds[i+1].Stdin, _ = cmd.StdoutPipe()
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}
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// Final ---> output buffer
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cmds[lastIndex].Stdout = &output
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// Start each command
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for _, cmd := range cmds {
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if err := cmd.Start(); err != nil {
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return &output, err
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}
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}
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// We should Wait() for each command to complete
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for _, cmd := range cmds {
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if err := cmd.Wait(); err != nil {
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return &output, err
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}
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}
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// Return the output
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return &output, nil
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}
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