Question

I saw a question on stackflow about parsing arguments. I tried to write this, but it’s not working and now it’s getting on my nerves.

The usual way of running a script on the terminal is ./scriptname, but I later introduced the argument -d. So, if I put ./scriptname it will not run. If I put ./scriptname -d it will.

Now I want to put another argument for the path (where the files are moving, in this case "/home/elg19/documents") such that when I do not include the path, it won’t run. But, if I put ./scriptname -d path I want to replace $To in the existing script with the command argument after -d.

#!/bin/bash
From="/home/mark/doc"
To=$2

if [ $1 = -d ]; then
    cd "$From"
    for i in pdf txt doc; do
      find . -type f -name "*.${i}" -exec mv "{}" "$To" \;
    done
fi

Answer 1

Your desired usage isn’t completely clear, but it seems to be:

scriptname -d path

So, you can do it the extensible way, or the brute force way. Since you’re changing directories willy-nilly, you also need to ensure that the paths are absolute, not relative.

Brute force

#!/bin/bash
From="/home/mark/doc"
if [ $# = 2 ] && [ "$1" = '-d' ] && [ -d $2 ]
then
    case "$2" in
    (/*) cd "$From" &&
         for extn in pdf txt doc
         do find . -type f -name "*.$extn" -exec mv {} "$To" \;
         done;;
    (*)  echo "$0: path name must be absolute ($2 is not)" 1>&2; exit 1;;
    esac
else
    echo "Usage: $0 -d /absolute/dirname" 1>&2; exit 1
fi

Extensible

#!/bin/bash
From="/home/mark/doc"
To=""

usage()
{
    echo "Usage: $(basename $0 .sh) -d /absolute/dirname" 1>&2
    exit 1
}

while getopts d: opt
do
    case "$opt" in
    (d)  if [ ! -d "$OPTARG" ]
         then echo "$0: $OPTARG is not a directory" 1>&2; exit 1
         else
             case "$OPTARG" in
             (/*) To="$OPTARG";;
             (*)  echo "$0: path name must be absolute ($2 is not)" 1>&2; exit 1;;
             esac
         fi;;
    (*)  usage;;
    esac
done
shift $(($OPTIND - 1))

if [ $# != 0 ] || [ -z "$To" ]
then usage
fi

cd "$From" &&
for extn in pdf txt doc
do find . -type f -name "*.$extn" -exec mv {} "$To" \;
done

For example, it will be very easy to add a -f from option to deal with changing the source of the files.

Note that you could also use:

for extn in pdf txt doc
do find "$From" -type f -name "*.$extn" -exec mv {} "$To" \;
done

This would allow you to permit relative names for the ‘from’ and ‘to’ directories because it does not change directory.