EC
io.ErrShortWrite
GoERRORNotableIO

short write

Quick Answer

Use io.WriteString or loop until all bytes are written, checking n against len(data).

What this means

Returned when a Write call writes fewer bytes than requested without returning an explicit error. Indicates a partial write condition.

Why it happens
  1. 1Underlying writer accepted fewer bytes than provided in a single call
  2. 2Network buffer full causing partial write without an OS error

Fix

Use io.WriteString or loop

Use io.WriteString or loop
_, err := io.WriteString(w, s)
if err != nil { log.Fatal(err) }

Why this works

io.WriteString retries internally until all bytes are accepted or an error occurs.

Code examples
Detectgo
n, err := w.Write(data)
if n < len(data) && err == nil {
    err = io.ErrShortWrite
}
Write loopgo
for len(data) > 0 {
    n, err := w.Write(data)
    data = data[n:]
    if err != nil { break }
}
bufio.Writer flushgo
bw := bufio.NewWriter(w)
bw.WriteString("hello")
bw.Flush()
Sources
Official documentation ↗

Go standard library

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