The filter sed can process text from standard input and write its results to standard output. The input can be redirected from a file, and the output also can be redirected to a file using your ...

The “l” at the beginning identifies /usr/bin/awk as a symbolic link. NOTE: Without the commas, the result would be “onetwothree”. Note that gawk allows you to ...

Unix utility SED provides an effective and versatile way of deleting one or more lines from a designated file to match the needs of the user. This Unix command is used for command line processing.

A key point to these tools (from a practical point ) is that they are very memory efficient and allow work on just a "line".

The sed (stream editor) command also does a great job of switching between upper- and lowercase. This command would have the same effect as the first of the two shown above.