I've got a Bash script which is only ever going to be invoked via a pipe. I'm curious what's the best way to read the data from the pipe? The command will look like:
$ output_gen | process
My script is process. This is not homework, but it is a learning exercise.
When your program is receiving data from a pipeline, it's received via stdin. To read from stdin, use the read builtin. Here is an example:
myprog:
while read -r line; do
<something with "$line">
done
command:
printf 'foo\nbar\n' | ./myprog
Method 1: You can use the ‘read command’ with a “while loop” to read from a pipe within a bash script.
#!/bin/sh
cat names.txt | while read name; do
echo "$name"
done
Method 2: You can use the ‘read command’ to read from a pipe within a script in the terminal. For example,
echo “Hello World!” | { read name; echo “msg=$name”; }
Method 3: If you want to read a command through pipe, you need a script like this: func.sh:
#!/bin/bash
function read_stdin()
{
cat > file.txt
}
read_stdin
This will take any command as input and redirect the output to file.txt. Try running:
date|./func.sh
