Using columns in bash - linux

Question

I've used the column command to split some of my output into 3 different columns. Problem is with the final column, the filetype output is being split into a 4th and 5th column because of the spaces.
Can somebody tell me how to change my code so that output stays under the Filetype column?
list_files()
{
if [ "$(ls -A ~/.junkdir)" ]
then
filesdir=/home/student/.junkdir/*
echo "Listing files in Junk Directory"
output="FILENAME SIZE(BYTES) TYPE \n\n---------------- ---------------- ------------------- "
for listed_file in $filesdir
do
file_name=$(basename "file $listed_file" | cut -d ' ' -f1)
file_size=$(du --bytes $listed_file | awk '{print $1}')
file_type=$(file $listed_file | cut -d ' ' -f2-)
output="$output\n${file_name} ${file_size} ${file_type}\n"
done
echo -ne $output | column -t
else
echo 'Junk directory is empty'
fi
}
The output at the moment..
Listing files in Junk Directory
FILENAME SIZE(BYTES) TYPE
---------------- ---------------- -------------------
files.txt 216 ASCII text
forLoop 401 Bourne-Again shell script,
ASCII text executable

Answer 1

I rarely give full solution, but it seems you are really stuck.
list_files2()
{
filesdir=/home/student/.junkdir/*
printf "FILENAME\1SIZE(BYTES)\1TYPE\1\n\n----------------\1----------------\1-------------------\n"
for listed_file in $filesdir
do
file_name=$(basename "file $listed_file" | cut -d ' ' -f1)
file_size=$(du --bytes $listed_file | awk '{print $1}')
file_type=$(file $listed_file | cut -d ' ' -f2-)
printf "%s\1%s\1%s\n" "${file_name}" "${file_size}" "${file_type}"
done
}
list_files()
{
if [ "$(ls -A ~/.junkdir)" ]
then
echo "Listing files in Junk Directory"
list_files2 | column -t -s $'\1'
else
echo 'Junk directory is empty'
fi
}
I slightly reorganized your code and made some other changes as well. I will explain what I did.
$'\1' is the 0x01 char. Even though I proposed to use $'\0', it's weird that my version of column has weird interaction with it appearing in the input. But in shell scripting practice, it's generally a bad idea to assume blank separator. In your case, you got caught by space, which is reasonable, because white space has so much overloaded meaning, you cannot prevent it from appearing in a human readable text. The solution to this is to consider using exotic chars like 0x00 or 0x01 as separator instead, which is almost always the case that it won't show up as a part of the text. So it's very safe to use and in fact, it's common in portable shell scripting to use 0x00 as separator.
Do not concatenate string like you did. In fact, there are couple problems with it.
one is you keep concatenating string while you don't really need the intermediate result.
another biteback is what if inside of your text, strings like \n exist and it should be interpreted as literal? echo -e is not going to distinguish that. yet another SO question on the road.
using printf in fact is more flavorable in shell, though I use echo a lot myself as well. Here the benefit of using printf is evident.
I don't have your files so I didn't try it, though I would expect it works. Let me know if there're glitches here and there.

Answer 2

Perhaps you can try
output="$output\n${file_name}\t${file_size}\t${file_type}\n"
...
echo -ne $output