Add `pwd` test

[yanhaowang]

update get_path.c

[yanhaowang]

I use the output of getcwd, realpath C functions, and $PWD environment variable to ensure the output of the pwd is correct.

1. realpath -> absolute path
2. getcwd -> absolute path
3. $PWD -> logical path

There are two positive test cases and one negative test case here.

1. positive test case 1: pwd in the common path.
2. positive test case 2: pwd in the path has soft_link.
3. negative test case3: pwd in the path has broken soft_link.

Problems:

1. In the pwd source code, it also uses the $PWD and getcwd function. My test case also uses this, will it a little duplicate?

[lwhsu]

After discussing with @bses30074_gmail.com , we will remove the use of get_path.c.

[yanhaowang]

• use different way to test.

[ngie]

bin/pwd/Makefile

5–6

Please put this down near .include <bsd.prog.mk>.

10

This seems superfluous.

bin/pwd/tests/pwd_test.sh

2

Copyright?

40

Bad indentation?

etc/mtree/BSD.tests.dist

42

This line shouldn't have been touched: please check to make sure the indentation is correct here.

[yanhaowang]

• Fix the file format.

[yanhaowang]

• Remove $FreeeBSD$

[ngie]

I'll work on getting this over the finish line.

[ngie]

It looks like @des wrote tests with similar coverage in D55153 and merged them into :main back in February. Taking differential/abandoning revision.