过滤掉破损的管道错误

The broken pipe error is defined in the syscall package. You can use the equality operator to compare the error to the one in syscall. Check http://golang.org/pkg/syscall/#constants for a complete list of syscall errors. Search "EPIPE" on the page and you will find all the defined errors grouped together.

if err == syscall.EPIPE {
    /* ignore */
}

If you wish to get the actual errno number (although it is pretty useless) you can use a type assertion:

if e, ok := err.(syscall.Errno); ok {
    errno = uintptr(e)
}

Having all but an error interface is enough to perform a type assertion or a type switch to reveal the concrete type held by the interface.