Shell Programming and Scripting

You don't.

Is the following file (scf) a shell script?:

Code:

$ ls -l scf
-------r--  1 dwc  staff  35 Apr 20 01:27 scf
$ cat scf
supercalifragilisticexpialidocious

It can be for someone whose user name is not dwc, does not have a primary group name or supplementary group name staff, and has an executable file named supercalifragilisticexpialidocious somewhere in their search path.

Although not the more efficient, your first attempt was pretty close. The main issue is your case line was ignored interpreted as a comment, starting with a "#".
I also removed '-name "*"' which is useless being always true.

Code:

find . -type f  -exec sh -c '
    case "$(head -n 1 "$1")" in
      \#!*) exit 0;;
    esac
exit 1
' sh {} \; -print

Answering to your last question, I would start with the "file" command. There is no simple heuristic to sort out shell scripts from other text files so most non shebanged scripts will show up as "ASCII text" with this command:

Code:

find . -type f -exec file {} + | grep text

There might be versions of find where -name "*" is everything but .*.
If this is intended then \! -name ".*" would be more clear.

*deleted by author*

According to the standards, -name "*" should match every path being evaluated. But, note that the entries . and .. are not evaluated unless they were named as operands on the command line.

You really can't.

All a user needs to do is source a file anyway. In bash:

Code:

bash 4.1$ . TextFile

That'll run through commands in TextFile just as if it were executable and started with "#!/bin/bash".

Not sure what the point of finding scripts is anyway, since all they do is the same thing the user can do with a command line.

And what about files .bashrc or .profile?

Check that the file is a text file that is executable?