1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.tradefed.util;
18 
19 import java.util.ArrayList;
20 import java.util.List;
21 
22 /**
23  * Utility used to parse(USER,PID and NAME) from the "ps" command output
24  */
25 public class PsParser {
26 
27     private static final String LINE_SEPARATOR = "\\n";
28     private static final String PROCESS_INFO_SEPARATOR = "\\s+";
29     private static final String BAD_PID = "bad pid '-A'";
30 
31     /**
32      * Parse username, process id and process name from the ps command output and convert to list of
33      * ProcessInfo objects.
34      *
35      * @param psOutput output of "ps" command.
36      * @return list of processInfo
37      */
getProcesses(String psOutput)38     public static List<ProcessInfo> getProcesses(String psOutput) {
39 
40         List<ProcessInfo> processesInfo = new ArrayList<ProcessInfo>();
41         if (psOutput.isEmpty()) {
42             return processesInfo;
43         }
44         String processLines[] = psOutput.split(LINE_SEPARATOR);
45 
46         /*
47          * (ps -A || ps) command prints "bad pid '-A'" as first line before the ps header in
48          * N and older builds so skip the first two lines.
49          */
50         int startLineNum = 1;
51         if (processLines[0].equals(BAD_PID)) {
52             startLineNum = 2;
53         }
54 
55         /*
56          * Sample output:
57          * USER PID PPID VSZ    RSS   WCHAN      PC  S NAME
58          * root   1   0  11140  1848  epoll_wait  0  S init
59          *
60          * Not collecting information other than USER,PID and NAME because they are
61          * not always printed for all the processess.
62          */
63         for (int lineCount = startLineNum; lineCount < processLines.length; lineCount++) {
64             String processInfoStr[] = processLines[lineCount].split(PROCESS_INFO_SEPARATOR);
65             ProcessInfo psInfo = new ProcessInfo(processInfoStr[0],
66                     Integer.parseInt(processInfoStr[1]), processInfoStr[processInfoStr.length - 1]);
67             processesInfo.add(psInfo);
68         }
69         return processesInfo;
70     }
71 
72 }
73 
74