Creating a Progress Bar in Bash
Have you ever wondered how to create a progress bar in a Bash script? Progress bars are a useful way to display how much time is left for a process to complete.
In this article, we will explore three different ways to create a progress bar in Bash. We will cover the topics in a practical, easy-to-follow way so that you can implement them in your own projects.
Example 1: Using printf Command
The printf command is a powerful utility that can format and print text in various ways. We can also use it to create a progress bar in Bash.
Here is an example of a Bash script that uses printf to create a progress bar:
“`bash
#!/bin/bash
progress-bar() {
local duration=$1
already_
done() { for ((
done=0;
done<(elapsed*50)/duration;
done++)); do printf “”;
done }
remaining() { for ((remain=(elapsed*50)/duration; remain<50; remain++)); do printf " ";
done }
elapsed=0
while [[ elapsed -lt duration ]]; do
already_
done; remaining; printf “r”
(( elapsed++ )); sleep 1
done
already_
done; printf “n”
}
progress-bar 10
“`
In this script, we define a function called “progress-bar” that takes in the duration of the process as a parameter. The function uses a for loop to print out a series of filled blocks () for the amount of time that has already elapsed, and empty blocks (spaces) for the remaining time.
The script uses the printf command to overwrite the previous output each time the progress bar is updated. The sleep command is used so that the progress bar is updated every second.
Example 2: Using pv Command
The pv command is a popular utility that can display the progress of data transfer processes. However, we can also use it to create progress bars for large files.
Here is an example of a Bash command that uses pv to create a progress bar for a large file:
“`bash
pv large-file.iso | dd of=/dev/sdb bs=4M
“`
In this command, we use the pv command to pipe the data from the “large-file.iso” file to the dd command. The dd command writes the data to the “/dev/sdb” device.
By piping the output through pv, we can see the progress of the transfer as a progress bar. Example 3: Using dialog Command
The dialog command is an interactive utility that can display dialogs and menus in Bash scripts.
We can also use it to create a progress bar for a file copying operation. Here is an example of a Bash script that uses dialog to create a progress bar for a file copy:
“`bash
#!/bin/bash
src_file=”/path/to/source/file”
dest_file=”/path/to/destination/file”
bytes_copied=0
total_bytes=$(wc -c < $src_file)
dialog –title “Copying File” –infobox “Copying $src_file to $dest_file…” 0 0
cp $src_file $dest_file | while read -r line; do
bytes_copied=$(($bytes_copied + $(echo $line | wc -c)))
percent=$((100 * $bytes_copied / $total_bytes))
dialog –title “Copying File” –gauge “Copying $src_file to $dest_file” 10 50 $percent
done
“`
In this script, we define the source and destination files. We then use the wc command to get the total number of bytes in the source file.
We use the dialog command to display an info box with the name of the source and destination files. We then use the cp command to copy the source file to the destination file.
We pipe the output of the cp command through a while loop that reads each line of output and updates the progress bar using the dialog command. The progress bar displays a percentage of the bytes copied, based on the total bytes in the source file.
Installation of Required Commands
The examples presented in this article require the installation of certain commands. Let’s take a look at how to install them.
Example 1: No installation required for printf command, as it is a built-in utility in Bash. Example 2: Installing pv Command
To install the pv command, use the following command in your terminal:
“`bash
sudo apt-get install pv
“`
This command installs the pv command on your system. Example 3: Installing dialog Command
To install the dialog command, use the following command in your terminal:
“`bash
sudo apt-get install dialog
“`
This command installs the dialog command on your system.
Conclusion
In conclusion, progress bars are a useful way to display the progress of a process in Bash. We can create progress bars using utilities like printf, pv, and dialog.
The examples presented in this article will help you get started with creating progress bars in Bash scripts. The installation of required commands is also straightforward, as demonstrated above.
We hope that this article provides you with the necessary knowledge to implement progress bars in your own projects. Progress bars are an essential component of any efficient and effective Bash script.
Developers use progress bars to provide real-time feedback to the user, improving the overall user experience and making it more interactive. In this article, we explored three different ways to create a progress bar in Bash.
The first example used the printf command, which is a built-in utility in Bash. We showed how to create a progress bar using printf by defining a function that accepts the duration of the process as a parameter.
The function used a for loop to calculate and display the number of blocks in the progress bar. The second example used the pv command, which is a popular utility that can display the progress of data transfer processes.
We showed how to use the pv command to create a progress bar for large files. We used the pv command to pipe the data from the source file to the dd command and display the progress bar for the transfer.
The third example used the dialog command, which is an interactive utility that can display dialogs and menus in Bash scripts. We showed how to use the dialog command to create a progress bar for a file copying operation.
We defined the source and destination files and used the dialog command to display an info box with the name of the source and destination files. We used the cp command to copy the source file to the destination file and piped the output of the cp command through a while loop to read each line of output and update the progress bar using the dialog command.
To use the first example, developers can simply copy and paste the function definition into their Bash script. Similarly, the second and third examples require the installation of the pv and dialog commands, respectively.
Developers can install these utilities using the apt-get installation command. Progress bars are highly beneficial to developers, making their work easier and more efficient.
They help track the progress of a long process, alert the user when the process is
done, and provide real-time feedback regarding the status of the task. When running long, resource-intensive tasks in Bash scripts, progress bars prove to be a vital tool to keep the user informed of the task’s progress.
The Bash script is a powerful scripting language that runs on various platforms, and it is essential for developers to know how to use progress bars effectively in their scripts. With the right progress bar implementation, developers can keep the user engaged and make their Bash scripts more interactive.
In conclusion, progress bars are an essential tool in any developer’s arsenal. In this article, we have explored how to create progress bars in Bash using various utilities such as printf, pv, and dialog commands.
By using progress bars, developers improve the overall user experience of their Bash scripts, helping them to interact more efficiently with their applications. In conclusion, creating progress bars in Bash scripts is an important feature that adds real-time feedback and user engagement.
This article gave an overview of three different methods to create progress bars. The first example showcased the use of the printf command, while the second relied on the pv command and the third implemented the dialog command.
These methods can improve the user experience of a Bash script and keep the user informed of the task’s progress. Therefore, it is essential for developers to know how to create progress bars effectively in their Bash scripts.
Implementing progress bars will make the script more efficient and easier to interact, providing a more enjoyable experience for the user.