Execution Privileges?

[davejjj]

Who is allowed to execute chmod on a file? Only the owner?

If I don't have x privilege for a file then why am I allowed to execute it by shelling out?

What files am I allowed to execute by shelling out?

Thanks.

[nujinini]

Hello davejjj,

May I please ask what you mean by "shelling out"?

Anyways, the owner or anybody with privileges as root (su -, or sudo) can chmod. If I am not mistaken.

[devils casper]

If I don't have x privilege for a file then why am I allowed to execute it by shelling out?

What do you mean by shelling out? Even google couldn't find out relevant info.
Have you checked manual of chmod command?

[elija]

Could shelling out be

bash myscript

although even in that case I'm not sure of the answer to the original question.

[jayd512]

You may be right, elija.
The only other thought I had would be specifying the path.

/entire/path/to/command

[Cabhan]

With regards to "shelling out":

Executing a script works differently from executing a compiled program. In particular, executing a script is simply giving input to another program. When you execute a script like:

#!/usr/bin/perl

LINES

The OS, behind the scenes, converts it to executing the program /usr/bin/perl, with the input of the script.

So, the answer to "why can you execute it by shelling out?" (assuming that shelling out means executing the script as "bash SCRIPT" instead of "./SCRIPT") is that as long as a user can read the file, he could input it into the interpreter program directly.

Note that if you had a script that was both unexecutable and unreadable, it could not be executed at all.

This does not apply to compiled programs, which are executed directly by the system. If a compiled program does not have executable privileges, it cannot be executed. However, if it is readable, it could be copied, the copy made executable, and then executed.

[jayd512]

Makes sense...
I think we're all just stuck here wondering, though, until the OP pops back in to explain what he means.

[davejjj]

Hello davejjj,

May I please ask what you mean by "shelling out"?

Anyways, the owner or anybody with privileges as root (su -, or sudo) can chmod. If I am not mistaken.

Oh, I'm sorry, I was led to believe that was the standard terminology. What I mean is that if you have written a script and you have not set the x bit for that file, you can still type...

sh ./myscript

...and execute the script. This led me to wonder whether this only worked because of the specifics of the situation. Thanks. Sorry for the delay in getting back here.