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Asked: 2017-09-05 01:34:09 +0800 CST

Bash script to create a directory

  • 772

I'm messing around with scripting, I am able to create a script which when run prompts me for a name for a new dir, creates it then creates several files, echoes lines out, then deletes it all.

What I would like to do is morph it slightly so it creates and names the directory all by itself!

Seems a pointless exercise I know, but messing around with it is the best way I learn.

Here is my current script:

#!/bin/bash   
echo "Give a directory name to create:"    
read NEW_DIR    
ORIG_DIR=$(pwd)    
[[ -d $NEW_DIR ]] && echo $NEW_DIR already exists, aborting && exit    
mkdir  $NEW_DIR    
cd $NEW_DIR    
pwd    
for n in 9 8 7 6 5 4 3 2 1 0    
do        
touch file$n    
done

ls file?    

for names in file?    
do       
echo This file is named $names > $names    
done

cat file?

cd $ORIG_DIR

rm -rf $NEW_DIR

echo "Goodbye"
command-line

4 Answers

  1. Best Answer

    Instead of using the read command in order to get the value ofNEW_DIR from the input, You can set hard-coded value for the NEW_DIR variable in the following way:

    replace the following line in your script:

    read NEW_DIR

    with the following line:

    NEW_DIR="new_dir_hard_coded_value"

    Link for more info about bash-scripting-tutorial/bash-variables

    • 6

  2. If you want a surprise, instead of hardcoding the name you could use a technique to generate a random string, for example

    NEW_DIR=$(tr -cd '[:alnum:]' < /dev/urandom | fold -w8 | head -n1)

    This sets NEW_DIR to a string of eight alphanumeric characters. Every time you run the script, the new directory will have a different random name...

    Or to get a random word, pick a dictionary from /usr/share/dict/ and use shuf, for example:

    $ shuf -n1 /usr/share/dict/british-english
soupier
$ shuf -n1 /usr/share/dict/british-english
penguins

    So

    NEW_DIR=$(shuf -n1 /usr/share/dict/british-english)
mkdir "$NEW_DIR"
...
    • 6

  3. Instead of prompting for user input, you can hardcode values into scripts by using variable assignment operator (=). Thus, the following two lines,

    echo "Give a directory name to create:"
read NEW_DIR

    can be replaced by a single line.

    NEW_DIR="whatever_name_you_please"


    BTW, I know this is not relevant to the question but in the for loop you used in your script, you can write shorthand code for the range. Instead of 9 8 7 6 5 4 3 2 1 0, you may write it as

     for n in {9..0}
    • 3

  4. You could even go one step further: You could tell "read" to offer a proposition for the folder name, accept it by pressing return or change it as you like:

    read -p "Give a directory name to create: " -ei "default_name" NEW_DIR;

    this would show a line:

    Give a directory name to create: default_name

    To combine with the above suggestions, you could do the following:

    # pre-set NEW_DIR to a value or to any random string 
# as suggested in the other answers
NEW_DIR="default_name"

# Prompt for new directory name, suggesting previously selected default answer
read -p "Give a directory name to create: " -ei "$NEW_DIR" NEW_DIR;

    Note that read -p "text" will prompt for the text and ask for the answer in the same line. If you want to stick to your code and have it ask for the 2-line-format you could do

    echo "Give a directory name to create:"  
read -ei "$NEW_DIR" NEW_DIR
    • 3