Bash script to copy the directory structure from source directory into target directory - linux

Question

I am very new to Bash scritping and to get some practice, I am attempting to write a script that takes in a source directory and a destination directory. The script will search the source directory and copy its structure of sub-directories into the target directory (any files will be ignored, just the directories themselves will be duplicated). The source directory can have any number of sub-directories at any depth. What would be the best way to achieve this? I have started by attempting to write a recursive function where, if a directory is found, the function is called recursively onto this directory. However, due to my lack of experience with scripting, I have been stumped.
Here is what I have so far:
#! /bin/bash
if [ ! $# -eq 2 ]; then
echo "ERROR: Script needs 2 arguments: $0 source/directory/ target/directory/"
exit
fi
SOURCE_DIR=$1
TARGET_DIR=$2
function searchForDirectory {
for FILE in ls $SOURCE_DIR/*; do #should be 'ls *current_directory*'
if [ -d $FILE ]; then
searchForDirectory #call function recursively onto $FILE
#Do stuff here to create copy of this directory in target dir
fi
done
}
if [ ! -d $SOURCE_DIR ]; then
echo "ERROR: Source directory does not exist"
exit
else
searchForDirectory
fi
I know that this is just a skeleton function, and a lot more work would need to be put into it, but I'm just looking for guidance as to whether this is the correct way to go about this before I go any further, and if so, what would be my next step? How do I pass a directory into my function?
EDIT: Here is my solution thanks to Ivan's help below
#! /bin/bash
if [ ! $# -eq 2 ]; then
echo -e "\nERROR: Script needs 2 arguments:\n$0 source/directory/ target/directory/\n"
exit
fi
function recursiveDuplication {
for file in `ls $1`; do
if [ -d $1/$file ] && [ ! -d $2/$file ]; then
mkdir $2/$file
recursiveDuplication $1/$file $2/$file
elif [[ $1/$file == *.png ]]; then
convert $1/$file $2/$file
fi
done
}
if [ ! -d $1 ]; then
echo -e "\nERROR: $1 does not exist\n"
exit
elif [ -d $2 ] && [ ! -w $2 ]; then
echo -e "\nERROR: You do not have permission to write to $2\n"
exit
elif [ ! -d $2 ]; then
echo -e "\nSUCCESS: $2 has been created"
mkdir $2
fi
recursiveDuplication $1 $2
There are two issues with this solution:
As Rany Albeg Wein explained below, using 'ls' is not a good solution - and I have seen why when there is a space in a directory/*.png name.
I am also attempting to copy any *.png file from the source to the target and convert it to a *.jpg image in the target. How can I do this? I am attempting to use ImageMagick's convert image.png image.jpg command, but do not know how to do so when the image.png is being referred to as $file?

Answer 1

you can simplify a lot
$ find a -type d | xargs -I d mkdir -p copy/d
copy the tree structure from directory a to new directory under copy
$ tree a
a
|-- b
| |-- c
| | `-- file4
| |-- d
| | `-- file4
| `-- file3
`-- file2
3 directories, 4 files
$ tree copy
copy
`-- a
`-- b
|-- c
`-- d
4 directories, 0 files

Answer 2

This solution has been tested with directory names containing special chars, a loop in the directory tree and a broken symbolic link.
There is bellow a stansard solution:
( cd source/ ; find . -depth -type d -printf "%p\0" | xargs -0 -I xxx mkdir -p ../destination/xxx )
And there is a second solution using gnu cpio:
( cd source/ ; find . -depth -type d -printf "%p\0" | cpio --null -pd ../destination )
The test:
$ mkdir -p source/a/ba/c/d/e
$ mkdir -p source/a/bb/c/d/e
$ mkdir -p source/a/b/ca/d/e
$ ln -s source/broken/link source/a/ba/c/d/e/broken
$ (cd source/a/ba && ln -s ../../a tree-loop)
$ mkdir -p source/z/"$(printf "\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37\40\41\42\43\44\45\46\47\72\73\74\75\76\77\100\133\134\135\1336\137\140\173\174\175\176\177dir")"
$ touch source/a/b/"$(printf "\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37\40\41\42\43\44\45\46\47\72\73\74\75\76\77\100\133\134\135\1336\137\140\173\174\175\176\177file")"
$ ls
source
$ find source -depth
source/z/??????????????????????????????? !"#$%&':;<=>?#[\][6_`{|}~?dir
source/z
source/a/ba/tree-loop
source/a/ba/c/d/e/broken
source/a/ba/c/d/e
source/a/ba/c/d
source/a/ba/c
source/a/ba
source/a/b/ca/d/e
source/a/b/ca/d
source/a/b/ca
source/a/b/??????????????????????????????? !"#$%&':;<=>?#[\][6_`{|}~?file
source/a/b
source/a/bb/c/d/e
source/a/bb/c/d
source/a/bb/c
source/a/bb
source/a
source
$ ( cd source/ ; find . -depth -type d -printf "%p\0" | xargs -0 -I xxx mkdir -p ../destination/xxx )
$ find destination/ -depth
destination/z/??????????????????????????????? !"#$%&':;<=>?#[\][6_`{|}~?dir
destination/z
destination/a/ba/c/d/e
destination/a/ba/c/d
destination/a/ba/c
destination/a/ba
destination/a/b/ca/d/e
destination/a/b/ca/d
destination/a/b/ca
destination/a/b
destination/a/bb/c/d/e
destination/a/bb/c/d
destination/a/bb/c
destination/a/bb
destination/a
destination/
The gnu cpio test:
$ rm -rf destination
$ ( cd source/ ; find . -depth -type d -printf "%p\0" | cpio --null -pd ../destination )
0 blocks
$ find destination -depth
destination/z/??????????????????????????????? !"#$%&':;<=>?#[\][6_`{|}~?dir
destination/z
destination/a/ba/c/d/e
destination/a/ba/c/d
destination/a/ba/c
destination/a/ba
destination/a/b/ca/d/e
destination/a/b/ca/d
destination/a/b/ca
destination/a/b
destination/a/bb/c/d/e
destination/a/bb/c/d
destination/a/bb/c
destination/a/bb
destination/a
destination

Answer 3

#!/bin/bash
# 1st argument - source dir, 2nd - destination
function rrr {
for i in `ls $1`
do
if [ -d $1/$i ]
then
mkdir $2/$i
rrr $1/$i $2/$i
fi
done
}
rrr $1 $2