Bash Listing Files and Directories: Exercises, Solutions, and Explanations
1.
Write a Bash script that lists all files and directories in the current directory.
Code:
#!/bin/bash
# List all files and directories in the current directory
ls -al
Output:
total 28 drwxr-xr-x 1 rg rg 512 Apr 17 18:23 . drwxr-xr-x 1 root root 512 Jan 17 2022 .. -rw-r--r-- 1 rg rg 2 Apr 15 22:40 abc.sh -rw------- 1 rg rg 2068 Apr 16 16:13 .bash_history -rw-r--r-- 1 rg rg 220 Jan 17 2022 .bash_logout -rw-r--r-- 1 rg rg 3771 Jan 17 2022 .bashrc drwxr-xr-x 1 rg rg 512 Apr 17 12:29 destination_dir -rw-r--r-- 1 rg rg 284 Apr 13 18:09 input.txt drwxr-xr-x 1 rg rg 512 Apr 17 14:04 new_dir drwxr-xr-x 1 rg rg 512 Apr 17 11:18 new_workarea -rw-r--r-- 1 rg rg 2 Apr 13 18:15 nums.txt -rw-r--r-- 1 rg rg 67 Apr 17 11:42 old_error.log -rw-r--r-- 1 rg rg 416 Apr 13 18:17 output.txt drwxr-xr-x 1 rg rg 512 Apr 17 16:04 parent_directory -rw-r--r-- 1 rg rg 655 Jan 17 2022 .profile drwxr-xr-x 1 rg rg 512 Jun 10 2022 .vim -rw------- 1 rg rg 6695 Apr 17 18:23 .viminfo
Explanation:
In the exercise above,
The script utilizes the "ls" command with the -al options to list all files and directories, including hidden ones, with detailed information.
2.
Write a Bash script that lists only the files in the current directory.
Code:
#!/bin/bash
# Bash script to list only files in the current directory
for file in *; do
if [ -f "$file" ]; then
echo "$file"
fi
done
Output:
abc.sh document.txt erorrrr.log file2.txt input.txt nums.txt old_error.log output.txt sample.txt test1.sh test.sh
Explanation:
In the exercise above,
- for file in ; do: This line starts a loop that iterates over each item in the current directory (). The * wildcard matches all files and directories in the current directory.
- if [ -f "$file" ]; then: This line checks if the current item ('$file') is a regular file using the -f test operator. If it is a regular file, the code inside the "if" block will be executed.
- echo "$file": This line prints the name of the file ('$file') to the standard output.
- done: This line marks the end of the loop.
3.
Write a Bash script that lists only the directories in the current directory.
Code:
# Bash script to list only directories in the current directory
for dir in */; do
if [ -d "$dir" ]; then
echo "$dir"
fi
done
Output:
destination_dir/ new_dir/ new_workarea/ parent_directory/ source_directory/ test/
Explanation:
In the exercise above,
- for dir in /; do: This line starts a loop that iterates over each item in the current directory (/). The */ pattern matches all directories in the current directory.
- if [ -d "$dir" ]; then: This line checks if the current item ('$dir') is a directory using the -d test operator. If it is a directory, the code inside the "if" block will be executed.
- echo "$dir": This line prints the name of the directory ('$dir') to the standard output.
- done: This line marks the end of the loop.
4.
Write a Bash script that lists all files and directories in a specific directory provided as an argument to the script.
Code:
#!/bin/bash
# Check if an argument is provided
if [ $# -ne 1 ]; then
echo "Usage: $0 directory_path"
exit 1
fi
# Check if the provided argument is a directory
if [ ! -d "$1" ]; then
echo "$1 is not a directory."
exit 1
fi
# List all files and directories in the provided directory
echo "Files and directories in $1:"
ls -al "$1"
Output:
ad@DESKTOP-3KE0KU4:~$ ./test1.sh test.txt test.txt is not a directory.
ad@DESKTOP-3KE0KU4:~$ ./test1.sh parent_directory Files and directories in parent_directory: total 0 drwxr-xr-x 1 rg rg 512 Apr 17 16:04 . drwxr-xr-x 1 rg rg 512 Apr 17 20:15 .. drwxr-xr-x 1 rg rg 512 Apr 17 16:04 workarea drwxr-xr-x 1 rg rg 512 Apr 17 16:04 workarea2
Explanation:
In the exercise above,
- if [ $# -ne 1 ]; then: This line checks if the number of arguments provided to the script is not equal to 1.
- echo "Usage: $0 directory_path": If the number of arguments is incorrect, this line prints the correct usage of the script.
- exit 1: This line exits the script with a non-zero status, indicating an error.
- if [ ! -d "$1" ]; then: This line checks if the provided argument (directory path) is not a directory.
- echo "$1 is not a directory.": If the provided argument is not a directory, this line prints an error message.
- echo "Files and directories in $1:": This line prints a message indicating the directory whose contents are going to be listed.
- ls -al "$1": This line lists all files and directories in the provided directory ('$1') along with detailed information (-al options for ls command).
5.
Write a Bash script that lists all hidden files (files starting with a dot) in the current directory.
Code:
#!/bin/bash
# List all hidden files in the current directory
for file in .*; do
if [ -f "$file" ]; then
echo "$file"
fi
done
Output:
.bash_history .bash_logout .bashrc .profile .viminfo
Explanation:
In the exercise above,
- for file in .*; do: This line starts a loop that iterates over each entry in the current directory starting with a dot.
- if [ -f "$file" ]; then: This line checks if the current entry is a regular file.
- echo "$file": If the current entry is a regular file, this line prints its name.
- done: This line marks the end of the loop.
6.
Write a Bash script that lists all files modified within the last 24 hours in the current directory.
Code:
#!/bin/bash
# List all files modified within the last 24 hours in the current directory
find . -type f -mtime -1 -print
Output:
./.viminfo ./destination_dir/abc.txt ./destination_dir/pqr.txt ./erorrrr.log ./old_error.log ./source_directory/abc.txt ./source_directory/pqr.txt ./test.sh ./test1.sh
Explanation:
In the exercise above,
find . -type f -mtime -1 -print: This command searches for files (-type f) in the current directory (.) that have been modified within the last 24 hours (-mtime -1) and prints their paths (-print).
7.
Write a Bash script that lists all files larger than 1MB in the current directory.
Code:
#!/bin/bash
# List all files larger than 1MB in the current directory
find . -type f -size +1M -exec ls -lh {} \;
Explanation:
In the exercise above,
find . -type f -size +1M -exec ls -lh {} \;: This command searches for files (-type f) in the current directory (.) that are larger than 1MB (-size +1M) and executes the ls -lh command on each of them to list their details in a human-readable format.
8.
Write a Bash script that lists all empty files in the current directory.
Code:
#!/bin/bash
# List all empty files in the current directory
find . -maxdepth 1 -type f -empty -exec ls -lh {} \;
Output:
-rw-r--r-- 1 rg rg 0 Apr 17 22:33 ./input.txt -rw-r--r-- 1 rg rg 0 Apr 18 07:44 ./input1.txt
Explanation:
In the exercise above,
find . -maxdepth 1 -type f -empty -exec ls -lh {} \;: This command searches for files ('-type f') in the current directory (.) that are empty ('-empty') and executes the "ls -lh" command on each of them to list their details in a human-readable format. The "-maxdepth 1" option ensures that only the files in the current directory are considered, not in its subdirectories.
9.
Write a Bash script that lists all files with a specific extension (e.g., ".txt") in the current directory.
Code:
#!/bin/bash
# List all files with a specific extension in the current directory
extension=".txt"
for file in *"$extension"; do
if [ -f "$file" ]; then
echo "$file"
fi
done
Output:
document.txt file2.txt input1.txt input.txt nums.txt output.txt sample.txt
Explanation:
In the exercise above,
- extension=".txt": This variable stores the specific extension you want to search for. You can change it to any desired extension.
- for file in *"$extension"; do: This loop iterates over all files in the current directory with the specified extension.
- if [ -f "$file" ]; then: This condition checks if the current item in the loop is a regular file.
- echo "$file": If the file is a regular file, its name is echoed, indicating that it matches the specified extension.
Bash Editor:
More to Come !
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