Matheus Sampaio Queiroga
1cd953f90f
Signed-off-by: Matheus Sampaio Queiroga <srherobrine20@gmail.com>
69 lines
2.1 KiB
Go
69 lines
2.1 KiB
Go
package ar
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import (
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"errors"
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"io/fs"
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"strconv"
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"strings"
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"time"
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)
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const arMagic = "!<arch>\n" // Ar magic header
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var (
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ErrInvalidFile error = errors.New("invalid ar file")
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)
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// Offset Length Name Format
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// ------------------------------------------------------------------
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// 0 16 File identifier ASCII
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// 16 12 File modification timestamp (in seconds) Decimal
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// 28 6 Owner ID Decimal
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// 34 6 Group ID Decimal
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// 40 8 File mode (type and permission) Octal
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// 48 10 File size in bytes Decimal
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// 58 2 Ending characters 0x60 0x0A
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type Header struct {
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Filename string // File name
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Size int64 // File size
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ModeTime time.Time // Mode date
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Mode fs.FileMode // Mode
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Owner, Group int64 // Owner and Group ID
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}
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func (head Header) gnuHeader() []byte {
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header := make([]byte, 60)
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for i := range header {
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header[i] = 0x20
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}
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copy(header[0:16], []byte(head.Filename))
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copy(header[16:28], []byte(strconv.FormatInt(head.ModeTime.Unix(), 10)))
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copy(header[28:34], []byte(strconv.FormatInt(head.Owner, 10)))
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copy(header[34:40], []byte(strconv.FormatInt(head.Group, 10)))
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copy(header[40:48], []byte(strconv.FormatInt(int64(head.Mode), 10)))
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copy(header[48:58], []byte(strconv.FormatInt(head.Size, 10)))
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header[58] = 0x60
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header[59] = 0x0A
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return header
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}
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func (head *Header) parseGnuHeader(header []byte) {
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head.Filename = strings.TrimSpace(string(header[0:16]))
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if head.Filename[len(head.Filename)-1] == '/' {
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head.Filename = head.Filename[:len(head.Filename)-1]
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}
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head.Size, _ = strconv.ParseInt(strings.TrimSpace(string(header[48:58])), 10, 64)
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head.Owner, _ = strconv.ParseInt(strings.TrimSpace(string(header[28:34])), 10, 64)
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head.Group, _ = strconv.ParseInt(strings.TrimSpace(string(header[34:40])), 10, 64)
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// Mode
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modeInt, _ := strconv.ParseUint(strings.TrimSpace(string(header[40:48])), 10, 32)
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head.Mode = fs.FileMode(modeInt)
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// Mode time
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modeTime, _ := strconv.ParseInt(strings.TrimSpace(string(header[16:28])), 10, 64)
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head.ModeTime = time.Unix(modeTime, 0)
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}
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