Process Substitution allows commands to communicate with each other by passing the output of one command as the input to another command, without using temporary files. It uses <() to pass output as input and >() to pass output to another command.
Examples:
- Sort the output of a command:
sort <(ls)
This will sort the output of the ls command. <(ls) passes the output of ls as input to sort.
- Use the output of a command as input to another:
grep pattern <(ls)
This will grep for pattern in the output of ls.
- Pass output of a command to another command's input:
diff <(command1) <(command2)
This will diff the output of command1 and command2.
- Send command's output to a file:
command >(file)
This will send the output of command to file instead of stdout.
So in summary, process substitution:
Allows commands to communicate without temporary files
Uses <() to pass output as input
Uses >() to pass output to another command
Enables powerful one-liners and data pipelines.
Hope this explanation helps! Let me know if you have any other questions.
Best Practices
Use process substitution when you want to pass the output of one command as input to another, without using temporary files.
Keep the commands simple. Long or complex commands can make the one-liner hard to read.
Use descriptive command names to make the one-liner self-documenting.
Examples:
Compare two directory listings:
diff <(ls -l directory1) <(ls -l directory2)
Search for a pattern in 'grep' output:
grep pattern <(grep -E "pattern" *)
Pipe 'find' output to 'sort':
<(find . -type f) | sort
In summary, process substitution allows you to pass the output of one command as input to another in a concise, temporary fashion - without using intermediate files. It can help compare, sort, search, and piping command outputs. Keeping the commands simple and self-documenting makes the one-liners easiest to understand and maintain.
Hope these use cases and best practices for process substitution help! Let me know if you have any other questions.
Disclaim: This article was created with Rix, which is a very smart AI tool.