hadoop/hadoop-common-project/hadoop-common/src/main/bin/hadoop

#!/usr/bin/env bash

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

function hadoop_usage()
{
  echo "Usage: hadoop [--config confdir] COMMAND"
  echo "       where COMMAND is one of:"
  echo "  archive -archiveName NAME -p <parent path> <src>* <dest>"
  echo "                       create a Hadoop archive"
  echo "  checknative [-a|-h]  check native Hadoop and compression "
  echo "                         libraries availability"
  echo "  classpath            prints the class path needed to get the"
  echo "                         Hadoop jar and the required libraries"
  echo "  credential           interact with credential providers"
  echo "  daemonlog            get/set the log level for each daemon"
  echo "  distch path:owner:group:permisson"
  echo "                       distributed metadata changer"
  echo "  distcp <srcurl> <desturl> "
  echo "                       copy file or directories recursively"
  echo "  fs                   run a generic filesystem user client"
  echo "  jar <jar>            run a jar file"
  echo "  jnipath              prints the java.library.path"
  echo "  key                  manage keys via the KeyProvider"
  echo "  version              print the version"
  echo " or"
  echo "  CLASSNAME            run the class named CLASSNAME"
  echo ""
  echo "Most commands print help when invoked w/o parameters."
}


# This script runs the hadoop core commands.

# let's locate libexec...
if [[ -n "${HADOOP_PREFIX}" ]]; then
  DEFAULT_LIBEXEC_DIR="${HADOOP_PREFIX}/libexec"
else
  this="${BASH_SOURCE-$0}"
  bin=$(cd -P -- "$(dirname -- "${this}")" >/dev/null && pwd -P)
  DEFAULT_LIBEXEC_DIR="${bin}/../libexec"
fi

HADOOP_LIBEXEC_DIR="${HADOOP_LIBEXEC_DIR:-$DEFAULT_LIBEXEC_DIR}"
# shellcheck disable=SC2034
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh" ]]; then
  . "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh"
else
  echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/hadoop-config.sh." 2>&1
  exit 1
fi

if [ $# = 0 ]; then
  hadoop_exit_with_usage 1
fi

COMMAND=$1
shift

case ${COMMAND} in
  balancer|datanode|dfs|dfsadmin|dfsgroups|  \
  namenode|secondarynamenode|fsck|fetchdt|oiv| \
  portmap|nfs3)
    hadoop_error "WARNING: Use of this script to execute ${COMMAND} is deprecated."
    COMMAND=${COMMAND/dfsgroups/groups}
    hadoop_error "WARNING: Attempting to execute replacement \"hdfs ${COMMAND}\" instead."
    hadoop_error ""
    #try to locate hdfs and if present, delegate to it.
    if [[ -f "${HADOOP_HDFS_HOME}/bin/hdfs" ]]; then
      # shellcheck disable=SC2086
      exec "${HADOOP_HDFS_HOME}/bin/hdfs" \
      --config "${HADOOP_CONF_DIR}" "${COMMAND}"  "$@"
    elif [[ -f "${HADOOP_PREFIX}/bin/hdfs" ]]; then
      # shellcheck disable=SC2086
      exec "${HADOOP_PREFIX}/bin/hdfs" \
      --config "${HADOOP_CONF_DIR}" "${COMMAND}" "$@"
    else
      hadoop_error "HADOOP_HDFS_HOME not found!"
      exit 1
    fi
  ;;
  
  #mapred commands for backwards compatibility
  pipes|job|queue|mrgroups|mradmin|jobtracker|tasktracker)
    hadoop_error "WARNING: Use of this script to execute ${COMMAND} is deprecated."
    COMMAND=${COMMAND/mrgroups/groups}
    hadoop_error "WARNING: Attempting to execute replacement \"mapred ${COMMAND}\" instead."
    hadoop_error ""
    #try to locate mapred and if present, delegate to it.
    if [[ -f "${HADOOP_MAPRED_HOME}/bin/mapred" ]]; then
      exec "${HADOOP_MAPRED_HOME}/bin/mapred" \
      --config "${HADOOP_CONF_DIR}" "${COMMAND}" "$@"
    elif [[ -f "${HADOOP_PREFIX}/bin/mapred" ]]; then
      exec "${HADOOP_PREFIX}/bin/mapred" \
      --config "${HADOOP_CONF_DIR}" "${COMMAND}" "$@"
    else
      hadoop_error "HADOOP_MAPRED_HOME not found!"
      exit 1
    fi
  ;;
  archive)
    CLASS=org.apache.hadoop.tools.HadoopArchives
    hadoop_debug "Injecting TOOL_PATH into CLASSPATH"
    hadoop_add_classpath "${TOOL_PATH}"
  ;;
  checknative)
    CLASS=org.apache.hadoop.util.NativeLibraryChecker
  ;;
  classpath)
    if [[ "$#" -eq 1 ]]; then
      CLASS=org.apache.hadoop.util.Classpath
    else   
      hadoop_finalize
      echo "${CLASSPATH}"
      exit 0
    fi
  ;;
  credential)
    CLASS=org.apache.hadoop.security.alias.CredentialShell
  ;;
  daemonlog)
    CLASS=org.apache.hadoop.log.LogLevel
  ;;
  distch)
    CLASS=org.apache.hadoop.tools.DistCh
    hadoop_debug "Injecting TOOL_PATH into CLASSPATH"
    hadoop_add_classpath "${TOOL_PATH}"
  ;;
  distcp)
    CLASS=org.apache.hadoop.tools.DistCp
    hadoop_debug "Injecting TOOL_PATH into CLASSPATH"
    hadoop_add_classpath "${TOOL_PATH}"
  ;;
  fs)
    CLASS=org.apache.hadoop.fs.FsShell
  ;;
  jar)
    CLASS=org.apache.hadoop.util.RunJar
  ;;
  jnipath)
    hadoop_finalize
    echo "${JAVA_LIBRARY_PATH}"
    exit 0
  ;;
  key)
    CLASS=org.apache.hadoop.crypto.key.KeyShell
  ;;
  version)
    CLASS=org.apache.hadoop.util.VersionInfo
  ;;
  -*|hdfs)
    hadoop_exit_with_usage 1
  ;;
  *)
    CLASS="${COMMAND}"
  ;;
esac

# Always respect HADOOP_OPTS and HADOOP_CLIENT_OPTS
hadoop_debug "Appending HADOOP_CLIENT_OPTS onto HADOOP_OPTS"
HADOOP_OPTS="${HADOOP_OPTS} ${HADOOP_CLIENT_OPTS}"

hadoop_add_param HADOOP_OPTS Xmx "${JAVA_HEAP_MAX}"

hadoop_finalize
hadoop_java_exec "${COMMAND}" "${CLASS}" "$@"