Discard output from the cd command when followed by pwd

[arkq]

This commits fixes the issue when cd is followed by the pwd in a bash one-liner which should get the directory in which the executed script is located. The problem with such approach is that the cd command can print the destination directory in case when one has the CDPATH environmental variable set.

From the man bash:

cd [-L|...] [dir]
Change the current directory to dir. [...] If a non-empty directory
name from CDPATH is used the absolute pathname of the new working
directory is written to the standard output.

Testing

I've only tested the runtime/tests/scripts/onert-test script, so I hope that the rest will be verified by CI. Now, in my setup I'm able to run it. Before that change the outcome was like this:

$ export CDPATH=.:$HOME
$ runtime/tests/scripts/onert-test nnpkg-test
ERROR: 'nnpkg-test' is not supported

ONE-DCO-1.0-Signed-off-by: Arkadiusz Bokowy [email protected]

[seanshpark]

plz split to separate PR for circle-mlir/* ,
and for each compiler/* to each PRs,
and infra/*

[seanshpark]

is this really needed?
what is the problem?

[arkq]

I've just checked this particular one-liner and you are right, everything is OK here!

So, here is the detailed explanation what is going on, and why I've raised this PR:

Create some directory in your $HOME, e.g. mkdir -p $HOME/dir/subdir, then create a bash script in it (and make it executable), like this:

$ cat $HOME/dir/subdir/test.sh
#!/bin/bash
SOURCEDIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
echo "Source dir: $SOURCEDIR"

Then run this script:

$ ./dir/subdir/test.sh 
Source dir: /home/arkq/dir/subdir
$ dir/subdir/test.sh
Source dir: /home/arkq/dir/subdir

Now set the CDPATH env variable and run the script again:

$ export CDPATH=$HOME:$HOME/dir
$ ./dir/subdir/test.sh
Source dir: /home/arkq/dir/subdir
$ dir/subdir/test.sh
Source dir: /home/arkq/dir/subdir
/home/a.bokowy/dir/subdir

In the second test, the cd "$(dirname "${BASH_SOURCE[0]}")" prints the destination directory /home/arkq/dir/subdir, so the entire one-liner gets duplicated output. HOWEVER, if the one-liner uses readlink -f, e.g.: SOURCEDIR="$(cd "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")" && pwd)" the cd gets the absolute path, and in such case the destination directory is not printed!

$ export CDPATH=$HOME:$HOME/dir/subdir
$ cd dir/subdir
/home/arkq/dir/subdir
$ cd $HOME
$ cd $HOME/dir/subdir
$ cd $HOME

So, now the question which approach is better, discarding output or using readlink -f? I think that discarding output is safer, because resolving symlinks will cd you into different directory structure if somewhere along the path symlink was used. Then, relative paths (ones with ../../../) will no longer work.

I will update this PR to account work this finding. Also I will split this PR info separate ones for different parts of this repo.

Many thanks for the review! :)

[seanshpark]

I've only tested the runtime/tests/scripts/onert-test script, so I hope that the rest will be verified by CI.

You should test all your changes. That said, posting 110 files in single PR is not good practice.
And current CI may not check all things, like the bash scripts.