github.com/apache/arrow/go/v7@v7.0.1/parquet/cmd/parquet_schema/main.go (about)

     1  // Licensed to the Apache Software Foundation (ASF) under one
     2  // or more contributor license agreements.  See the NOTICE file
     3  // distributed with this work for additional information
     4  // regarding copyright ownership.  The ASF licenses this file
     5  // to you under the Apache License, Version 2.0 (the
     6  // "License"); you may not use this file except in compliance
     7  // with the License.  You may obtain a copy of the License at
     8  //
     9  // http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  
    17  package main
    18  
    19  import (
    20  	"fmt"
    21  	"os"
    22  
    23  	"github.com/apache/arrow/go/v7/parquet/file"
    24  	"github.com/apache/arrow/go/v7/parquet/schema"
    25  	"github.com/docopt/docopt-go"
    26  )
    27  
    28  const usage = `Parquet Schema Dumper.
    29  Usage:
    30    parquet_schema -h | --help
    31    parquet_schema <file>
    32  Options:
    33    -h --help   Show this screen.`
    34  
    35  func main() {
    36  	args, _ := docopt.ParseDoc(usage)
    37  	rdr, err := file.OpenParquetFile(args["<file>"].(string), false, nil, nil)
    38  	if err != nil {
    39  		fmt.Fprintln(os.Stderr, "Error opening parquet file: ", err)
    40  		os.Exit(1)
    41  	}
    42  
    43  	schema.PrintSchema(rdr.MetaData().Schema.Root(), os.Stdout, 2)
    44  }