Bug#1053394: dash should not propagate aliases to subshells
On Tue, Oct 3, 2023, at 5:54 AM, Дилян Палаузов wrote: > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_03_01 > > says: > > 2.3.1 Alias Substitution > > When used as specified by this volume of POSIX.1-2017, alias definitions > shall not be inherited by separate invocations of the shell or by the > utility execution environments invoked by the shell. > > > So a subshell shall have no knowledge about the aliases from the > supershell You are mistaken; subshells are not "separate invocations". See section 2.12: A subshell environment shall be created as a duplicate of the shell environment, except that signal traps that are not being ignored shall be set to the default action. > These programs > > #!/bin/bash > alias wslpath=echo > find `wslpath /tmp` > > and > > #!/bin/dash > alias wslpath=echo > find `wslpath /tmp` > > produce different results (bash 5.2.15-3.fc38, dash 0.5.12-1.fc38) when > executed on a WSL2 system. The former program shows the content of the > current directory, the latter program shows the content of /tmp . That is because aliases are not expanded at all in noninteractive bash "native mode" shells. If you were to run bash as "sh" or with its "--posix" option, then you would see the same behavior as with dash. -- vq
Bug#1053394: dash should not propagate aliases to subshells
To: 1053...@bugs.debian.org, d...@vger.kernel.org Hello, https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_03_01 says: 2.3.1 Alias Substitution When used as specified by this volume of POSIX.1-2017, alias definitions shall not be inherited by separate invocations of the shell or by the utility execution environments invoked by the shell. So a subshell shall have no knowledge about the aliases from the supershell, and backticks start a subshell. These programs #!/bin/bash alias wslpath=echo find `wslpath /tmp` and #!/bin/dash alias wslpath=echo find `wslpath /tmp` produce different results (bash 5.2.15-3.fc38, dash 0.5.12-1.fc38) when executed on a WSL2 system. The former program shows the content of the current directory, the latter program shows the content of /tmp . Moreover, I filled this initially towards the Debian Bug tracking system (cf. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1053394) , and was then told to check http://gondor.apana.org.au/~herbert/dash/ . Please include in the repository https://git.kernel.org/pub/scm/utils/dash/dash.git links to http://gondor.apana.org.au/~herbert/dash/ and d...@vger.kernel.org , for instance in src/dash.1, so that it is documented where to report problems in dash. Kind regards Dilyan
Bug#1053394: dash should not propagate aliases to subshells
Control: tag -1 upstream Hello, On Tue, 3 Oct 2023, at 10:53, Дилян Палаузов wrote: > I use actually dash on Fedora version 0.5.12-1.fc38, but the only way to > report bugs towards dash seems to be the Debian bug tracker system. You can report bugs directly to the dash upstream developer at d...@vger.kernel.org as described here: http://gondor.apana.org.au/~herbert/dash/ If would be great if you submitted this issue to them. Thanks! -- Cheers, Andrej
Bug#1053394: dash should not propagate aliases to subshells
Package: dash Version: 0.5.12-6 Hello, I use actually dash on Fedora version 0.5.12-1.fc38, but the only way to report bugs towards dash seems to be the Debian bug tracker system. https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_03_01 says: 2.3.1 Alias Substitution When used as specified by this volume of POSIX.1-2017, alias definitions shall not be inherited by separate invocations of the shell or by the utility execution environments invoked by the shell. So a subshell shall have no knowledge about the aliases from the supershell, and backticks start a subshell. These programs #!/bin/bash alias wslpath=echo find `wslpath /tmp` and #!/bin/dash alias wslpath=echo find `wslpath /tmp` produce different results (bash 5.2.15-3.fc38) when executed on a WSL2 system. The former program shows the content of the current directory, the latter program shows the content of /tmp . Kind regards Dilyan
