04.05.2017, 17:54, "Eduardo Bustamante" <dual...@gmail.com>: > On Wed, May 3, 2017 at 5:40 PM, Nikolay Aleksandrovich Pavlov (ZyX) > <kp-...@yandex.ru> wrote: > [...] >> If $PATH in bash contains ~ (e.g. `PATH='~/bin'`) it is incorrectly >> treated >> as if $HOME is present. > > Hm. You can start bash in POSIX mode > (https://www.gnu.org/software/bash/manual/bash.html#Bash-POSIX-Mode) > if you want to disable this feature. i.e. > > dualbus@debian:~$ bash --posix -c 'printf "%s\n" "#!/bin/bash" > "echo hi" > ~/cmd; chmod +x ~/cmd; PATH=\~; declare -p PATH; cmd' > declare -x PATH="~" > bash: cmd: command not found > > dualbus@debian:~$ bash -c 'printf "%s\n" "#!/bin/bash" "echo hi" > > ~/cmd; chmod +x ~/cmd; PATH=\~; declare -p PATH; cmd' > declare -x PATH="~" > hi
POSIX mode is inconvenient to use: different rc files, a bunch of differences regarding scripts, other things. No process substitution, this is a stopper. > > Bash's behavior here is intentional by the way, review the function > find_in_path_element in > http://git.savannah.gnu.org/cgit/bash.git/tree/findcmd.c?h=devel#n527, > it will perform tilde expansion if the path component starts with a > tilde. Perhaps it should be documented under > https://www.gnu.org/software/bash/manual/bash.html#Bourne-Shell-Variables > that bash treats tildes inside PATH specially. > > Also, I think it's a bit of a stretch to call this a security problem. > The scenario you describe (a user having a directory literally named > `~' with a bin subdirectory, a malicious program creating evil > binaries in $HOME/bin, the user having a misconfigured PATH, ...) is > highly unlikely. There still is a consistency problem. $PATH is not a bash-specific variable for it to have bash-specific features, and I really saw such bugs in either vim-dev or neovim bug tracker (not sure, can’t construct a good search to look for non-letter characters like tilde). More likely in Neovim because in Vim it would need to have &shell set not to bash. Also actually found an [issue][1] in powerline, it does not have that much bugs to search. This is going to be a problem in all cases when bash is used with something which searches in $PATH, but is not bash, so if intentional it is a misfeature. [1]: https://github.com/powerline/powerline/issues/850
