cp: making cp compatible with "same-file" gnu test case #6158
Description
Hi,
currently, our cp is failing gnu test case same-file, so I'm using this issue to log my findings and to discuss how to approach the problems. From my initial impression, same-file is failing for a number of reasons, and I'm listing them out here.
-b is not respecting VERSION_CONTROL environment variable.
It says in here that whenever --backup is given with an argument it takes precedence over VERSION_CONTROL and it also says that -b is equivalent to --backup=existing that means when -b is given cp should ignore the VERSION_CONTROL and set the backup method to "existing" and this is how uu-cp works, but gnu's implementation seems to respect the VERSION_CONTROL environment variable when -b is given.
gnu's cp
~ >> touch foo
~ >> touch bar
~ >> export VERSION_CONTROL=numbered
~ >> cp -b foo bar
~ >> ls
bar bar.~1~ foo
our cp
~ >> touch foo
~ >> touch bar
~ >> export VERSION_CONTROL=numbered
~ >> cp -b foo bar
~ >> ls
bar bar~ foo
difference in behaviors and error messages
this test case fails also because of the way how uutil-cp handles error code and messages, the following tables show the difference between two implementations, behaviors that should be changed are marked with these
when a file(foo) is copied to the symlink(symlink -> foo) that points to the same file
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | 1 | 1 | "cp: 'foo' and 'symlink' are the same file" | "cp: 'foo' and 'symlink' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -d | 1 | 1 | "cp: 'foo' and 'symlink' are the same file" | "cp: 'foo' and 'symlink' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -f | 1 | 1 | "cp: 'foo' and 'symlink' are the same file" | "cp: 'foo' and 'symlink' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -df | 1 | 1 | "cp: 'foo' and 'symlink' are the same file" | "cp: 'foo' and 'symlink' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| --rem | 0 | 0 | none | none | "foo symlink" | "foo symlink" | none | none |
| -b | 0 | 0 | none | none | " |
"foo symlink symlink.~1~ -> foo" | none | none |
| -bd | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -bf | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -bdf | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -l | 1 | 1 | " |
"cp: cannot create hard link 'symlink' to 'foo'" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -dl | 1 | 1 | " |
"cp: cannot create hard link 'symlink' to 'foo'" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -fl | " |
0 | " |
none | " |
"foo symlink" | none | none |
| -dfl | " |
0 | " |
none | " |
"foo symlink" | none | none |
| -bl | 0 | 0 | none | none | " |
"foo symlink symlink.~1~ -> foo" | none | none |
| -bdl | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -bfl | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -bdfl | " |
0 | " |
none | " |
"foo symlink symlink.~1~ -> foo" | symlink-loop | none |
| -s | 1 | 1 | " |
"cp: cannot create symlink 'symlink' to 'foo'" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -sf | " |
0 | " |
none | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
when a symlink(symlink -> foo) that points to a file(foo) is copied to the same file
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -d | " |
1 | " |
"cp: 'symlink' and 'foo' are the same file" | " |
"foo symlink -> foo" | symlink-loop symlink-loop | none |
| -f | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -df | " |
1 | " |
"cp: 'symlink' and 'foo' are the same file" | " |
"foo symlink -> foo" | symlink-loop symlink-loop | none |
| --rem | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -b | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -bd | 0 | 0 | none | none | " |
"foo -> foo foo.~1~ symlink -> foo" | symlink-loop symlink-loop | symlink-loop symlink-loop |
| -bf | " |
1 | " |
"cp: 'symlink' and 'foo' are the same file" | " |
"foo symlink -> foo" | cp FAILED cp FAILED | none |
| -bdf | 0 | 0 | none | none | " |
"foo -> foo foo.~1~ symlink -> foo" | symlink-loop symlink-loop | symlink-loop symlink-loop |
| -l | " |
0 | " |
none | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -dl | 0 | 0 | none | none | " |
"foo symlink -> foo" | symlink-loop symlink-loop | none |
| -fl | " |
0 | " |
none | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -bl | " |
0 | " |
none | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -bfl | " |
0 | " |
none | " |
"foo symlink -> foo" | symlink-loop symlink-loop | none |
| -s | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
| -sf | 1 | 1 | "cp: 'symlink' and 'foo' are the same file" | "cp: 'symlink' and 'foo' are the same file" | "foo symlink -> foo" | "foo symlink -> foo" | none | none |
when a file(foo) is copied to the same file(foo)
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -d | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -f | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -df | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| --rem | 1 | 1 | " |
"cp: 'foo' and 'foo' are the same file" | " |
"foo" | symlink-loop symlink-loop | none |
| -b | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -bd | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -bf | 0 | 0 | none | none | " |
"foo foo.~1~" | cp FAILED cp FAILED | none |
| -bdf | 0 | 0 | none | none | " |
"foo foo.~1~" | cp FAILED cp FAILED | none |
| -l | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -dl | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -fl | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -dfl | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -bl | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -bdl | 0 | 0 | none | none | "foo" | "foo" | none | none |
| -bfl | 0 | 0 | none | none | " |
"foo foo.~1~" | none | none |
| -bdfl | 0 | 0 | none | none | " |
"foo foo.~1~" | none | none |
| -s | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
| -sf | 1 | 1 | "cp: 'foo' and 'foo' are the same file" | "cp: 'foo' and 'foo' are the same file" | "foo" | "foo" | none | none |
when a symlink(sl1 -> foo) that points to a file(foo) is copied to another symlink(sl2 -> foo) that points to same file
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | 1 | 1 | "cp: 'sl1' and 'sl2' are the same file" | "cp: 'sl1' and 'sl2' are the same file" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -d | 0 | 0 | none | none | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -f | 1 | 1 | "cp: 'sl1' and 'sl2' are the same file" | "cp: 'sl1' and 'sl2' are the same file" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -df | 0 | 0 | none | none | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| --rem | 0 | 0 | none | none | "foo sl1 -> foo sl2" | "foo sl1 -> foo sl2" | none | none |
| -b | 0 | 0 | none | none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bd | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -bf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -bdf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -l | 1 | 1 | " |
"cp: cannot create hard link 'sl2' to 'sl1'" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -fl | " |
0 | " |
none | " |
"foo sl1 -> foo sl2" | none | none |
| -bl | 0 | 0 | none | none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bfl | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -s | 1 | 1 | " |
"cp: cannot create symlink 'sl2' to 'sl1'" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -sf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> sl1" | none | none |
when a file(foo) is copied to hardlink(hardlink) of the same file
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | 1 | 1 | "cp: 'sl1' and 'sl2' are the same file" | "cp: 'sl1' and 'sl2' are the same file" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -d | 0 | 0 | none | none | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -f | 1 | 1 | "cp: 'sl1' and 'sl2' are the same file" | "cp: 'sl1' and 'sl2' are the same file" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -df | 0 | 0 | none | none | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| --rem | 0 | 0 | none | none | "foo sl1 -> foo sl2" | "foo sl1 -> foo sl2" | none | none |
| -b | 0 | 0 | none | none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bd | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -bf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -bdf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -l | 1 | 1 | " |
"cp: cannot create hard link 'sl2' to 'sl1'" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -fl | " |
0 | " |
none | " |
"foo sl1 -> foo sl2" | none | none |
| -bl | 0 | 0 | none | none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bfl | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -s | 1 | 1 | " |
"cp: cannot create symlink 'sl2' to 'sl1'" | "foo sl1 -> foo sl2 -> foo" | "foo sl1 -> foo sl2 -> foo" | none | none |
| -sf | " |
0 | " |
none | " |
"foo sl1 -> foo sl2 -> sl1" | none | none |
when a symlink(hlsl) that points to a file(foo) is copied to the hardlink(sl2) of the same symlink
| Options | Exit status | Exit status(GNU) | std error | std error(GNU) | Files in the folder after copying | Files in the folder after copying(GNU) | remarks | remarks(gnu) |
|---|---|---|---|---|---|---|---|---|
| none | " |
1 | " |
"cp: 'hlsl' and 'sl2' are the same file" | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -d | 0 | 0 | none | none | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -f | 1 | 1 | "cp: 'hlsl' and 'sl2' are the same file" | "cp: 'hlsl' and 'sl2' are the same file" | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -df | " |
0 | " |
none | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| --rem | 0 | 0 | none | none | "foo hlsl -> foo sl2" | "foo hlsl -> foo sl2" | none | none |
| -b | 0 | 0 | none | none | " |
"foo hlsl -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bd | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -bf | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -bdf | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 -> foo sl2.~1~ -> foo" | symlink-loop | none |
| -l | " |
1 | " |
"cp: cannot create hard link 'sl2' to 'hlsl'" | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -dl | 0 | 0 | none | none | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -fl | " |
0 | " |
none | " |
"foo hlsl -> foo sl2" | none | none |
| -dfl | " |
0 | " |
none | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -bl | 0 | 0 | none | none | " |
"foo hlsl -> foo sl2 sl2.~1~ -> foo" | none | none |
| -bdl | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 -> foo" | symlink-loop | none |
| -bfl | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 sl2.~1~ -> foo" | symlink-loop | none |
| -bdfl | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 -> foo" | symlink-loop | none |
| -s | " |
1 | " |
"cp: cannot create symlink 'sl2' to 'hlsl'" | "foo hlsl -> foo sl2 -> foo" | "foo hlsl -> foo sl2 -> foo" | none | none |
| -sf | " |
0 | " |
none | " |
"foo hlsl -> foo sl2 -> hlsl" | none | none |