Ubuntu – Can anyone explain why sudo ls with a wildcard doesn’t work

bashcommand linesudowildcards

$ sudo -iu abc ls -ltr /sites/servers/server_instance/logs/access*
ls: cannot access /sites/servers/server_instance/logs/access*: No such file or directory

$ sudo -iu abc ls -ltr /sites/servers/server_instance/logs/
total 594812
-rwxrwxrwx 1 abc abc      45 Mar 21 12:42 old.log
-rwxrwxrwx 1 abc abc      304537970 Mar 24 12:45 console.log
-rwxrwxrwx 1 abc abc      304537970 Mar 24 13:20 access_nginx.log

Can anyone explain why this happens? I am stuck on a script due to this.

Best Answer

  • One possibility is that you don't have permissions to access one or more of the directories in that path (/sites/servers/server_instance/logs). The wildcard expansion is carried out by your shell, and then the expanded paths are passed to the sudo command.

    If your user doesn't have permissions, expansion wouldn't work in the first command. It would be run as-is (ls -ltr /sites/servers/server_instance/logs/access*), and there isn't a file literally named access*). If abc does have the required permissions for all the directories in the path, the second command, which didn't have any wildcards, would be untouched by your shell, and it would work fine.

    $ sudo namei -lx foo/bar/baz
    f: foo/bar/baz
    drwxr-xr-x muru    muru    foo
    drwx------ test    test    bar
    drwxr-xr-x muru    muru    baz
    
    $ sudo ls foo/bar/b*
    ls: cannot access 'foo/bar/b*': No such file or directory
    
    $ sudo -u test ls foo/bar/
    baz