Appendix C. A Sed and Awk Micro-Primer

This is a very brief introduction to the sedand awk text processing utilities. We willdeal with only a few basic commands here, but that will sufficefor understanding simple sed and awk constructs within shellscripts.

sed: a non-interactive text file editor

awk: a field-oriented pattern processing language with a C-style syntax

For all their differences, the two utilities share a similar invocation syntax, use regular expressions , read input by default from stdin, and output to stdout. These are well-behaved UNIX tools, and they work together well. The output from one can be piped to the other, and their combined capabilities give shell scripts some of the power of Perl.