Recursively list files from a given directory in Bash

Question

I know that it can be done using ls -R path. But I'm trying to learn the syntax and control structures of the shell language, so I'm trying to write my own code:

#!/bin/sh

arg=$1;

lsRec() {
    for x in $1*; do
        if [ -d "$x" ]; then
            lsRec $x;
        else
            echo "$x";
        fi
    done
}

lsRec $arg;

When I call the command ./ej2.sh ~/Documents/, the terminal throws: segmentation fault (core dumped). Why I'm getting this error?, Am I missing something in my code?

Thanks.

Answer 1

Your algorithm is entering endless loop since lsRec function implicitly expects its argument to end in "/". First level works, as you pass path ending with "/" as input, but second level doesn't, as the path you're making recursive call with doesn't end in "/". What you could do is either add the slash when you make a recursive call, so it'll look like lsRec $x/, or (better yet) add the slash in the loop arguments as in for x in $1/*; do (as system generally ignores multiple adjacent path separators).

Moving forward, I'd advise you to quote the values (e.g. for x in "$1/"*, lsRec "$x", lsRec "$arg") to avoid issues when path contains whitespace characters. You'll get there when you create a directory with space in its name under directory hierarchy you're scanning.