你这里的 test.abc = 5 最好改成 test.abc = htons(5)，
然后 Go 这边你用 encoding/binary 就可以读了，参见：

$ go doc encoding/binary.Read
package binary // import "encoding/binary"

func Read(r io.Reader, order ByteOrder, data interface{}) error
    Read reads structured binary data from r into data. Data must be a pointer
    to a fixed-size value or a slice of fixed-size values. Bytes read from r are
    decoded using the specified byte order and written to successive fields of
    the data. When decoding boolean values, a zero byte is decoded as false, and
    any other non-zero byte is decoded as true. When reading into structs, the
    field data for fields with blank (_) field names is skipped; i.e., blank
    field names may be used for padding. When reading into a struct, all
    non-blank fields must be exported or Read may panic.

    The error is EOF only if no bytes were read. If an EOF happens after reading
    some but not all the bytes, Read returns ErrUnexpectedEOF.

【 在 lioncat7 (lioncat) 的大作中提到: 】
: 收json，发送私有协议udp
: udp对应c代码大概是
: struct demo｛
: int abc；
: char content[32];
: ｝;
: struct demo test;
: memset(&test, 0, sizeof(test));
: test.abc =5;
: strcpy(test.content, "my test");
: send(fd, &test, sizeof(test));
: go里面好像不能指定string的固定长度，我解析json之后，难道只能一个字节一个字节赋值？
--
修改:flw FROM 27.38.197.*
FROM 27.38.197.*

27 bytes 那里可以简化一下，
直接用 bytes.Repeat 生成个切片发出去就好了，类似于 memset：

$ go doc bytes.Repeat

package bytes // import "bytes"

func Repeat(b []byte, count int) []byte
    Repeat returns a new byte slice consisting of count copies of b.

    It panics if count is negative or if the result of (len(b) * count)
    overflows.

【 在 lioncat7 (lioncat) 的大作中提到: 】
: 写完了， 感谢指路
: 部分关键代码
: import (
:     "encoding/binary"
: )
:     buff := bytes.NewBuffer([]byte{})
:     var abc int32
:        abc = 7777
:     err = binary.Write(buff, binary.BigEndian, &abc)
:     if err != nil {
:         log.Panic(err)
:     }
:         content := "abcdefg"
:       err = binary.Write(buff, binary.BigEndian, []byte(content))
:       if err != nil {
:               log.Panic(err)
:       }
:     var zeroByte uint8
:         /* fixed length 27 bytes */
:     end := 27 - len(content)
:     for i := 1; i <= end; i++ {
:         err = binary.Write(buff, binary.BigEndian, &zeroByte)
:         if err != nil {
:             log.Panic(err)
:         }
:     }
:     sendBuff := buff.Bytes()
:     _, err = socket.Write(sendBuff) // 发送数据
:     if err != nil {
:         fmt.Println("发送数据失败，err: ", err)
:         return
:     }
--
FROM 27.38.197.*