Bash script segmentation fault

Question

My assignment is to write a bash script that reads a directory and returns the file type of each file within, including all subdirectories. Using the find command is not allowed. I've tried to implement this using essentially two for loops, but I'm getting a segmentation fault. I found that the script does work however when I pass a directory without subdirectories. Would someone be willing to look over a noob's code and tell me what's wrong? Thank you very much.

#!/bin/bash
func () {
for name in $1
do
  if [ -f "$name" ]
  then
    file "$name"
  elif [ -d "$name" ]
  then
    func "$1"
  fi
done
}

directory="$1/*"
for name in $directory
do
  if [ -f "$name" ]
  then
    file "$name"
  elif [ -d "$name" ]
  then
    func "$1"
  fi
done

Answer 1

If the "$name" it's processing is a directory, you need to call func on its contents, and not the original argument, or you get an infinite loop, and hence the segfault.

Your code can be greatly reduced by using a function on the original argument, and have the function apply to each item separately. Right now you're repeating most of what happens in the function in the main body anyway.

#!/bin/bash
func () {
    local arg="$1"
    if [[ -f "$arg" ]] ; then
        file -- "$arg"
        return
    fi
    if [[ -d "$arg" ]] ; then
        for file in "$arg"/* ; do
            func "$file"
        done
    fi
}

func "$1"

Answer 2

The simplest approach, if you can use bash features, is to enable globstar and use that:

shopt -s globstar
for f in "$1"/**; do 
    if [ -f "$f" ]; then 
        file -- "$f"
    fi
done

Using the logic in your original script, you just need to give it the right input:

#!/bin/bash
func () {
for name in "$1"/*
do
  if [ -f "$name" ]
  then
    file "$name"
  elif [ -d "$name" ]
  then
    func "$name"
  fi
done
}

directory="$1"
for name in "$directory"/*
do
  if [ -f "$name" ]
  then
    file "$name"
  elif [ -d "$name" ]
  then
    func "$name"
  fi
done

You were using func $1 instead of func $name so you were entering an endless loop which led to the segfault. Next time, just add an echo to see what you are processing, that would have shown you the error immediately.

Also, you really don't need to repeat code like that. The whole point of functions is to avoid such repetition, so you could simply do:

#!/bin/bash
func () {
for name in "$1"/*
do
  echo "FF $name"
  if [ -f "$name" ]
  then
    file "$name"
  elif [ -d "$name" ]
  then
    func "$name"
  fi
done
}

directory="$1"
for name in "$directory"/*
do
  func "$name"
done