Bash script error when trying to create a snapshot

Question

I am trying to create a snapshot using Bash script as below but error occurred.

Environment: FreeBSD, Version: 13.2, Script: Bash

#!/usr/local/bin/bash
name="17102023_1234"
zfs snapshot data/library@$name

run this simple bash script but received error as shown below.

' in named character ' 'data/library@17102023_1234

It works when I put '17102023_1234' after @ instead of variable.

Any help is appreciated. Thanks.

Answer 1

• Gerald Schneider pointed out one "invisible" mistake. Some other operatings systems use two bytes, carriage return (CR) and line feed, to indicate the end of a line. POSIX™‑compliant systems like FreeBSD (mostly is) use, however, only one line feed byte, the CR thus becomes part of the line’s payload.

  name="17102023_1234"␍␊
  

  Gerald’s hypothesis is that the value of name becomes 17102023_1234␍ (the ␍ byte is invisible), so

  zfs snapshot data/library@$name
  

  calls the command

  zfs snapshot data/library@17102023_1234␍
  

  Typically this problem originates from copy‑pasting. You can use dos2unix of the converters/unix2dos port or simply annihilate the CR bytes with

  sed -e's/\r//' -i'' ./my_sript.sh # substitute CR with ε in‑place
  

• FYI, the time and date are already part of every snapshot: inspect the creation property. I use a plain counter as snapshot name because from the creation property alone you cannot learn whether there existed any intermediate snapshots.