How Do I Filter in Linux?

What is filter command in Linux?

Filters are programs that take plain text(either stored in a file or produced by another program) as standard input, transforms it into a meaningful format, and then returns it as standard output. Linux has a number of filters.

What is filter command?

Filters are commands that always read their input from ‘stdin’ and write their output to ‘stdout’. Users can use file redirection and ‘pipes’ to setup ‘stdin’ and ‘stdout’ as per their need. Pipes are used to direct the ‘stdout’ stream of one command to the ‘stdin’ stream of the next command.