Re: here strings fold newlines on MacOS

On 30/01/2021 22:44, Rich Lafferty wrote:
> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: darwin18.7.0
> Compiler: clang
> Compilation CFLAGS: -DSSH_SOURCE_BASHRC
> uname output: Darwin flounder.home.mati.ca 18.7.0 Darwin Kernel Version 18.7.0: 
> Tue Nov 10 00:07:31 PST 2020; root:xnu-4903.278.51~1/RELEASE_X86_64 x86_64
> Machine Type: x86_64-apple-darwin18.7.0
>
> Bash Version: 5.1
> Patch Level: 0
> Release Status: release
>
> Description:
> Here strings ('<<<') fold newlines into spaces on MacOS, but not on Linux,
> leading to incompatibilites in bash code expected to work the same on both
> platforms.
>
> Repeat-By:
>
> On Linux:
>
> $ od -bc <<< $(echo -e "foo\nbar")
> 0000000 146 157 157 012 142 141 162 012
>   f o o \n b a r \n
> 0000010
>
> On MacOS:
>
> $ od -bc <<< $(echo -e "foo\nbar")
> 0000000 146 157 157 040 142 141 162 012
>   f o o b a r \n
> 0000010

Are you certain that you're not testing /bin/bash (version 3.2.57) in 
the case of macOS? I ask because the bug you describe is said to have 
been addressed by the release of 4.4-beta [1].

z.  Bash no longer splits the expansion of here-strings, as the
    documentation has always said.

You can work around it by double quoting the command substitution.

[1] https://tiswww.case.edu/php/chet/bash/CHANGES

--
Kerin Millar