Is there a way to redirect Echo to stdin?
By default this is connected to the terminal screen, but can be redirected by using the > symbol or the program name being on the left side of a pipe. takes the standard output from echo and passes it to the standard input of echo. But echo does not read stdin! So nothing happens. Filter programs process the filenames specified on the command-line.
What happens when you pipe data into a shell script?
In your case, your script provides its standard input for each command that it runs. A simple example script: Piping data into your shell script causes cat to read that data, since cat inherits its standard input from your script.
What happens to the second echo in Bash?
So the second echo prints all of its arguments (none) and exits, ignoring the Hello on stdin. For a program that reads its stdin and prints that to stdout, use cat: In this case the pipe you are using are more correctly known as anonymous pipes, because they have no name (there are also named pipes ).
What’s the name of the second pipe in Bash?
The second, 1, is known as standard output, or stdout. By default this is connected to the terminal screen, but can be redirected by using the > symbol or the program name being on the left side of a pipe.
What are some examples of Echo not working?
Filter programs process the filenames specified on the command-line. If no filenames are given then they read stdin. Examples include cat, grep, and sed, but not echo. For example: will display ‘Hello’, and the cat is useless (it often is). will ignore the output from echo and just display the contents of file1.
Why is my Echo program not reading stdin?
But echo does not read stdin! So nothing happens. Filter programs process the filenames specified on the command-line. If no filenames are given then they read stdin. Examples include cat, grep, and sed, but not echo. For example: will display ‘Hello’, and the cat is useless (it often is).