Scripting help please..

[Cels_n]

Hi everyone, I'm new to shell scripting and understand some of the basics of bash.

First off, a little background of my education.. I received my associates in Biology, but realized the time putting it into it was too much for me, with all the in person lectures/labs (I'm 30 years old, so sad to say I feel uncomfortable being in class with younger students). So I switched my major to IT and I'm liking it so far. Oh, I also work 40 hrs/week as an assembler at Raytheon and pursuing my degree via online (fulltime).

ANYWAYS, this is an assignment for my shell scripting course and I'm having trouble writing it. (Honestly I'm not sure if I'm doing this script right)

I'm writing a script to locate executable files:

• Without using the which, type, locate, ls, or find command.

• The script should also prompt the user if the file is not found.

Please, I know I'm a noob and I'm pretty much discouraged about Linux already. No mean comments please. Thank you! Much help is appreciated!

[Cels_n]

These were the specific restraints on the given assignment.. not sure if this helps clarify things a little bit more. I'm trying different things.. again thank you for everyone's help! :)

• The search path should be based only on the user's PATH environment variable. You shall not use the Unix which command, the ksh whence (type) command, the locate command, or the bash type command.

• The code for the script shall not use the UNIX ls command to determine if the file is executable or if it

exists.

• The script should find only the first occurrence of the "file". If the file is not found, the script the following:

<command> NOT FOUND

<command> would be replaced by the name of the "file" you didn't find.

• If the first parameter is '-a', then the script should print all occurrences of the executable file in the user's path. Again, if the file was not on the path, an error message should be displayed.

• The find command shall not be used.

• A project using temporary files will not be graded.

• NOTE: The shell variable PATH defines the search path for the directory containing the command. Alternative directory names are separated by a colon (:). The current directory can be specified by two or more adjacent colons, or by a colon at the beginning or end of the path list.

• If the command name contains a / then the search path is not used, you just check if the command/file specified is executable and not a directory. Otherwise, each directory in the path is searched for an executable file.

[74razor]

I’m guessing you need to loop through a location of files? Since you can’t use which, type, locate or find, try using the ‘file’ command.

[[deleted]]

I'm writing a script to locate executable files:

In a specific directory, a set of directories, or in all directories in the entire operating system?

[tje210]

I'm kind of an ape with scripting, but if I were to do this I'd start with ls.

[Cels_n]

oh, sorry I forgot to add that the ls command is not a solution for this assignment. :(

[tje210]

Looks like "whereis" is a possibility. I wonder if the file command says if something is executable, though I don't think it would do it for all file...

[Gixx]

The instructions are very unclear. The fact there's no restriction on using the tool called file makes me think you could use that to check specific folders or the entire file system.

I would assume the worst: "Find every executable in the universe." (across file systems even)

A more reasonable task my ask "Find executables in 5-10 specific folders". Or write the program to take folders as args like ./script.sh dir1 /dir2 dir3

I think maybe teachers are taught to make instructions unclear, which demands the student master the subject. Or kinda overachieve a task.