Print Byte Slice As String

ID

go.print_byte_slice_as_string

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Code Smell

Language

Go

Tags

CWE:1164, code-style, readability

Description

Reports a []byte argument passed to a fmt print function (Print, Println, Sprint, Sprintln, Fprint, Fprintln) without a string conversion.

Rationale

Without a conversion, those functions render a byte slice as its decimal byte values ([104 105]) rather than the text it holds. Wrapping it in string(b) prints the intended characters and reads more clearly. The rule fires only for an unnamed []byte — either a []byte(…​) conversion or a so-typed identifier; named byte-slice types are left alone because they may implement fmt.Stringer, in which case the print is already correct.

import "fmt"

func fn(b []byte) {
    fmt.Print(b)         // FLAW — prints byte values
    fmt.Print(string(b)) // OK
}

Remediation

Convert the byte slice with string(b) before printing it.

References