6 ms·

The script does echo variables: echo "banned command $cmd: $output" This is non-portable if there is any possibility that these variables contain backslas

• nequo 4y ago
  TIL: dash$ x="foo\nasd" dash$ echo "$x" foo asd dash$ printf "%s\n" "$x" foo\nasd dash$ zsh% x="foo\nasd" zsh% echo "$x" foo asd zsh% printf "%s\n" "$x" foo\nasd zsh% bash$ x="foo\nasd" bash$ echo "$x" foo\nasd bash$ printf "%s\n" "$x" foo\nasd bash$
  • fragmede 4y ago
    bash$ echo -e $x foo asd bash$
  • norvvryo 4y ago
    Enlightening From POSIX: >echo - write arguments to standard output >If the first operand is -n, or if any of the operands contain a <backslash> character, the results are implementation-defined.
    • deleted 4y ago
      [deleted]
  • remram 4y ago
    Wow, TIL indeed. That's conformant to the Single UNIX Specification as well: https://pubs.opengroup.org/onlinepubs/007908799/xcu/echo.html https://pubs.opengroup.org/onlinepubs/007908799/xcu/echo.htm...
• TechBro8615 4y ago
  The script is for static analysis, so it only needs to run once against each code change, and in theory it shouldn't need to be portable code, unless the code under test is the static analysis code itself. In other words, they control where this script runs and there is no need to run it on more than one platform, so it's okay for it to be non-portable.
  • hvdijk 4y ago
    That's fine if the script only runs on shells that behave the same way, but the script runs under bats, which runs on bash and appears to not change its xpg_echo shell option. This shell option controls echo's behaviour on bash and has a compile-time-configurable default; even scripts that are only meant to run on bash cannot assume either behaviour for echo, as different vendors use different defaults for the option.