control.go

Documentation: github.com/sassoftware/relic/lib/signdeb

     1  //
     2  // Copyright (c) SAS Institute Inc.
     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 signdeb
    18  
    19  import (
    20  	"archive/tar"
    21  	"bufio"
    22  	"bytes"
    23  	"compress/bzip2"
    24  	"compress/gzip"
    25  	"errors"
    26  	"io"
    27  	"io/ioutil"
    28  	"path"
    29  	"strings"
    30  
    31  	"github.com/xi2/xz"
    32  )
    33  
    34  type PackageInfo struct {
    35  	Package, Version, Arch string
    36  }
    37  
    38  // Parse basic package info from a control.tar.gz stream
    39  func parseControl(r io.Reader, ext string) (*PackageInfo, error) {
    40  	var err error
    41  	switch ext {
    42  	case ".gz":
    43  		r, err = gzip.NewReader(r)
    44  	case ".bz2":
    45  		r = bzip2.NewReader(r)
    46  	case ".xz":
    47  		r, err = xz.NewReader(r, 0)
    48  	case "":
    49  	default:
    50  		err = errors.New("unrecognized compression on control.tar")
    51  	}
    52  	if err != nil {
    53  		return nil, err
    54  	}
    55  	tr := tar.NewReader(r)
    56  	found := false
    57  	for {
    58  		hdr, err := tr.Next()
    59  		if err == io.EOF {
    60  			break
    61  		} else if err != nil {
    62  			return nil, err
    63  		}
    64  		if path.Clean(hdr.Name) == "control" {
    65  			found = true
    66  			break
    67  		}
    68  	}
    69  	if !found {
    70  		return nil, errors.New("control.tar has no control file")
    71  	}
    72  	blob, err := ioutil.ReadAll(tr)
    73  	if err != nil {
    74  		return nil, err
    75  	}
    76  	info := new(PackageInfo)
    77  	scanner := bufio.NewScanner(bytes.NewReader(blob))
    78  	for scanner.Scan() {
    79  		line := scanner.Text()
    80  		i := strings.IndexAny(line, " \t\r\n")
    81  		j := strings.Index(line, ":")
    82  		if j < 0 || i < j {
    83  			continue
    84  		}
    85  		key := line[:j]
    86  		value := strings.Trim(line[j+1:], "  \t\r\n")
    87  		switch strings.ToLower(key) {
    88  		case "package":
    89  			info.Package = value
    90  		case "version":
    91  			info.Version = value
    92  		case "architecture":
    93  			info.Arch = value
    94  		}
    95  	}
    96  	if scanner.Err() != nil {
    97  		return nil, scanner.Err()
    98  	}
    99  	if info.Package == "" || info.Version == "" {
   100  		return nil, errors.New("control file is missing package and/or version fields")
   101  	}
   102  	return info, nil
   103  }
   104
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