Re: [PATCH] set bash env variables before running scripts

On 13/3/22 08:58, Andrew Gregory wrote:

Bash sources user configuration files under a number of conditions that can cause issues with scripts when bash is used as the scriptlet shell.

Bash assumes it's being run under rsh/ssh if stdin is connected to a socket and sources the user bashrc unless the environment variable $SHLVL is >= 2. Commit 6a4c6a02de9b45abe4c0f78c4f5d14d92d3359d6 switched from pipes to sockets when communicating with child processes to work around SIGPIPE issues. Normally $SHLVL would be inherited from the shell running pacman, but operations involving scriptlets are generally run with sudo which does not let the $SHLVL variable through unless specifically configured to.

Similarly $BASH_ENV can cause bash to source user-specified configuration files if set.

https://lists.gnu.org/archive/html/help-bash/2022-02/msg00082.html

Signed-off-by: Andrew Gregory ---

Not entirely sure we should actually be unsetting $BASH_ENV, but Chet recommended it.

lib/libalpm/util.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c index 06e0fe7f2..7340ce832 100644 --- a/lib/libalpm/util.c +++ b/lib/libalpm/util.c @@ -659,6 +659,11 @@ int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const argv[], "/", strerror(errno)); exit(1); } + /* bash thinks it's being run under rsh/ssh if stdin is a socket and + * sources ~/.bashrc unles SHLVL is > 1 */

Typo

+ setenv("SHLVL", "1", 0);

From reading everything, I expected this to be >=2. I'm entirely lost why it is set to 1!

+ /* bash sources $BASH_ENV when run non-interactively */ + unsetenv("BASH_ENV"); umask(0022); _alpm_reset_signals(); execv(cmd, argv);