Does the parent directory have permissions on the subdirectory? [Linux]

Source of the problem:

Log on to the server (a server account in the lab), want to create a file in the current directory, but prompt "file system Read Only", unable to create the file. by ls-l

View the current user's permissions in the current directory and discover that they have RWX permissions. So I thought maybe it was because I didn't have W permissions in my parent directory that I couldn't create a file in the current directory.

But found in the parent directory I also rwx permissions ... (Finally, I feel the problem may be that the server administrator has write protection to the hard drive)

So I did the following experiment to verify that the permissions of the parent directory to subdirectories have no effect? "For example, I have no write permission in the parent directory (TESTDIR), I am in the current directory

(testdir/abc/) Can I perform a write operation?

LxW ~$ls-LDtestdir/DRWXRWXR-X3LxW LxW4096Dec -  the:Tentestdir/LxW~$chmod  -testdir/LxW~$ls-LDtestdir/ Dr-X------ 3LxW LxW4096Dec -  the:Tentestdir/LxW~$ CD testdir/LxW testdir$Touchparentfile #合理, no w permission for TestDirTouch: CannotTouch' parentfile ': Permission Deniedlxw testdir$ls-Ltotal8DRWXRWXR-X2LxW LxW4096Dec - Ten: -ABC-rw-rw-r--1LxW LxW4Dec -  the:TenTxtlxw testdir$ CD ABC/LxW abc$lsLxW abc$TouchChildfile #父目录虽然没有w权限, but as long as I have access to the current directory (with x permission), I am able to follow my permissions in the current directory. LxW abc$lsChildfile

So, after the above authentication, although the parent directory does not have the W permission, but as long as I can enter the current directory (with x permission), I can follow my permissions in the current directory, do

Operation.

Now I leave the testdir/directory with only X permissions:

LxW ~$chmod  -testdir/LxW~$ ll-d testdir/ D--x------ 3LxW LxW4096Dec -  the:TenTestDir//LxW ~$ CD testdir/LxW testdir$ls #合理, no r permission ls: Cannot open Directory.: Permission Deniedlxw testdir$ ll-d ABC #虽然我在testDir/no r permission to see what files it has, but if I know beforehand what files it has, I can view these files through LS. DRWXRWXR-X2LxW LxW4096Dec - Ten: -abc/LxW testdir$ ll txt #同上-rw-rw-r--1LxW LxW4Dec -  the:TenTxtlxw testdir$Toucha #合理, no W permissionTouch: CannotTouch' a ': Permission Deniedlxw testdir$ cd Abclxw abc$lsChildfilelxw abc$ ll-LD. DRWXRWXR-X2LxW LxW4096Dec - Ten: -./LxW abc$TouchChildFile2 #虽然我在父目录中没有rw权限, but as soon as I get to the directory (x permission), I can follow my permissions in the current directory. LxW abc$ls-Ltotal0-rw-rw-r--1LxW LxW0Dec - Ten: -Childfile-rw-rw-r--1LxW LxW0Dec - Ten: -ChildFile2

So, through the above experiment, I think that as long as the parent directory has x permissions, the permissions of the parent directory and the permissions of the subdirectories are not directly related and do not affect each other .

Finally, the following example further illustrates:

LxW ~$chmod  -testdir/LxW~$ls-LDtestdir/ drw------- 3LxW LxW4096Dec -  the:Tentestdir/LxW~$ CD testdir/#合理, no X permissionsBash:cd:testDir/: Permission Deniedlxw~$ls-L testdir/#有r权限ls: Cannot access testdir/Txt:permission deniedls: Cannot access testdir/abc:permission deniedtotal0D?????????            ? ? ? ? ?ABC-?????????            ? ? ? ? ?txtLxW ~$ cd testdir/abcbash:cd:testDir/Abc:permission denied

Last statement, I have RWX permission to the ABC directory, I have RW permission on TestDir, but I can't enter TESTDIR/ABC ( the permissions of the parent directory affect the

subdirectories , because I don't have X permissions on TestDir.

If you have any different views, you are welcome to communicate with me.

Does the parent directory have permissions on the subdirectory? [Linux]