I am trying to run one of the example from Beej's Guide to Network Programming (https://beej.us/guide/bgnet/), specifically showip.c (The link to the program is here: https://beej.us/guide/bgnet/examples/showip.c). Using gcc, I've typed in

gcc -o showip showip.c

Then ran the program

showip www.example.net

and I get an error showip: command not found on the same directory where the code and the program is compiled at. I'm not sure why this is the case. I've even cloned the code from his GitHub and used makefile to compile the program and yet I'm getting the same error. What exactly am I doing it wrong here?

CodePudding user response：

This is actually problem with how you're running the program.

On Linux systems (unlike Windows systems) an executable in the current directory is not by default searched by the shell for programs to run. If the given program does not contain a path element (i.e. there are no / characters in the name) then only the directories listed in the PATH environment variable are searched.

Since the current directory is not part of your PATH, prefix the command with the directory:

./showip www.example.net

CodePudding user response：

Since the program showip is not in your $PATH you have to tell your shell that it's in the current directory:

./showip

Or add the current directory to your $PATH but it's a less secure option:

PATH=:$PATH

or

PATH=.:$PATH

and run it as you're trying now:

showip

CodePudding user response：

Is the working directory on your path? Likely not.

Try ./showip