Re^5: system call windows

And I never understood the predilection *nix people have for "avoiding the shell". It seems to me that all of the justifictions I've read ... could equally be done to the program you ask the shell to run on your behalf.

The major issue I see with it is interpolating user input into the shell command. If one uses fixed strings, or one makes sure that any variables interpolated into the command are always sanitized, then I have no problem with using the shell. The problem arises when people aren't aware of the potential security issues, do the escaping wrong, or when scripts start out with "safe" use of the shell but are later modified to accept different user input and the maintainer forgets to properly sanitize the inputs accordingly. Hence my usual advice to just avoid the shell in the first place, and only use it if one knows what one is doing.

Comment on Re^5: system call windows

Replies are listed 'Best First'.
Re^6: system call windows by BrowserUk (Patriarch) on Mar 10, 2019 at 21:40 UTC
Hence my usual advice to just avoid the shell Hm. Sounds a little like advising people to wear condoms at all times rather than just when appropriate. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". The enemy of (IT) success is complexity. In the absence of evidence, opinion is indistinguishable from prejudice. Suck that fhit	[reply]
Re^7: system call windows by haukex (Archbishop) on Mar 10, 2019 at 23:01 UTC
Hence my usual advice to just avoid the shell [... and only use it if one knows what one is doing.] Sounds a little like advising people to wear condoms at all times rather than just when appropriate. That's a pretty good analogy for what I said: If one knows and trusts one's user, one doesn't need to "wear a condom" and can put their input into the shell unprotected (although it can still be useful to prevent accidents). But if one is going to be sleeping with the entire internet...	[reply]