When to take input inside a while loop in Bash?
If you are using the direct output of a command to feed a while loop in BASH, you may still want to take user input inside that loop. For example, if you need the user to confirm each line by pressing . Take a simple example like this:
How can I use a file in a command and redirect output?
Basically I want to take as input text from a file, remove a line from that file, and send the output back to the same file. Something along these lines if that makes it any clearer. grep -v ‘seg[0-9]\\{1,\\}\\.[0-9]\\{1\\}’ file_name > file_name however, when I do this I end up with a blank file. Any thoughts? bashredirectio Share
How to save the output of one command?
FYI, if you don’t want to save the output to a file, but just view it in the terminal, use “-” instead of a filename to indicate stdout. wget also accepts stdin with the – switch. If you want to save the output in a file, use the -O switch.
How to read from the console while looping over?
Take a simple example like this: You may (wrongly!) expect this to loop over each matched line, and allow the user to press on each match. It will NOT provide the user a chance to respond because the input of read will come from the output of the initial command.
How to read input from the console in Bash?
Bash: Reading input from the console while looping over output of command. If you are using the direct output of a command to feed a while loop in BASH, you may still want to take user input inside that loop. For example, if you need the user to confirm each line by pressing . Take a simple example like this:
When do you USE FOR loop in Linux?
We can use for loop for iterative jobs. Linux system administrators generally use for loop to iterate over files and folder. In this tutorial, we will look at how to use for loop to iterate over files and directories in Linux.
Which is the negation of a for loop in Bash?
Notice that the negation of the test condition [ $num -le 10 ]; is [ $num -gt 10 ]; If you are following this tutorial series from start, you should be familiar with arrays in bash. For loops are often the most popular choice when it comes to iterating over array elements.
How to write a non-blocking Arduino library?
It’s simple and readable, yet effective. Since then I’ve figured out how to rewrite the code to be non-blocking, by replacing the while loop with states, accumulating one byte at a time. I’ve written my first Arduino library with this occasion: Mindwave .