keeping track of a moving shell script - linux

Question

I hope someone can help me out. For the past month or so I have be learning the Bash... I have a program ( a simple language study program ) that I want to be able to install and run from a script.
I have a script that will create a new folder and move itself into it. The way I am doing it at the moment is below, although I have had problems with arrays that I am using later. I was wondering if there was a cleaner way of getting the new path to file name. Any help or insight would be greatly appreciated.
#!/bin/bash
echo "# path to me ---------------> ${0} "
echo "# parent path --------------> ${0%/*} "
echo "# my name ------------------> ${0##*/} "
if [[ ! -d ${0%/*}/SomeNewFolder ]] && [[ ! -d ${0%/*}/../SomeNewFolder ]]
then
mkdir ${0%/*}/SomeNewFolder
mv ${0} ${0%/*}/SomeNewFolder/${0##*/}
fi
echo ${0%/*}
newpath=$(echo "${0%/*}/SomeNewFolder")
echo $newpath
All the best, Ben
exit

Answer 1

For clarity, I would probably declare named variables for your common values instead of constantly reusing the ${0} array. It's also good practice to quote variables and strings.
The only major issue I saw, was running ./script.sh would make $0 equal just the filename, so I add "./" to the beginning in that case.
#!/bin/bash -u
ME="${0}"
if [[ ! "$ME" =~ /^\// ]]; then
ME="./$ME"
fi
PARENT="${ME%/*}"
FILENAME="${ME##*/}"
FOLDER="SomeNewFolder"
NEW="$PARENT/$FOLDER"
if [[ ! -d "$NEW" ]] && [[ "${PARENT%/*}" != "$FOLDER" ]]; then
mkdir "$NEW"
mv "$ME" "$NEW"
fi
echo "$PARENT"
echo "$NEW"

Answer 2

Well, you could do something like this to get an absolute path:
PARENTPATH=$( cd "$( dirname "$0" )" && pwd )
NEWPATH=${PARENTPATH}/SomeNewFolder

Answer 3

me="$0"
newdir=SomeNewFolder
if [[ $me =~ ^/ ]] ; then
full_path="$me"
else
full_path="$PWD/$me"
fi
full_path="${full_path//\/\.\///}" # prettify
path_to_me="${full_path%/*}"
parent_dir="${path_to_me##*/}"
if [ ! "$parent_dir" = "$newdir" ] ; then
mkdir -p "$path_to_me/$newdir"
mv -f "$full_path" "$path_to_me/$newdir/"
fi
Basically similar to what lunixbochs was doing, but with a few minor alterations
lower case variable names so as not to be confused with environment variables
crudely estimates absolute path
-f and -p becuase interactivity is never cool, and why not

Answer 4

Installing and setting up programs is more appropriately done from a make file. Granted, it seems intimidating at first, but the basics, such as what you want, are quite simple. For your project, you would ideally have three item:
your program
your run script
your makefile i.e. your installer
This breaks apart each of these different components, making each of them easier to manage. If you tar them together, you can move the tar file to a new computer and reinstall without any changes. Bash is a wonderful tool, but an installer it is not.
Sample make script below:
.PHONY: all clean
SCRIPT=yourScriptName.sh
SUBFOLDER=someFolder
all: $(SCRIPT)
$(SCRIPT): $(SUBFOLDER)
cp $(SCRIPT) $(SUBFOLDER)
$(SUBFOLDER):
mkdir $(SUBFOLDER)
clean:
-rm -f $(SUBFOLDER)/$(SCRIPT)
-rmdir $(SUBFOLDER)
IMPORTANT! make is whitespace sensitive! Those indents are tabs not four spaces.