Appendix C. A Sed and Awk Micro-Primer
- Table of Contents
- C.1. Sed
- C.2. Awk
This is a very brief introduction to the sed
and awk text processing utilities. We will
deal with only a few basic commands here, but that will suffice
for understanding simple sed and awk constructs within shell
scripts.
sed: a non-interactive text file editor
awk: a field-oriented pattern processing
language with a C-like syntax
For all their differences, the two utilities share a similar
invocation syntax, both use regular
expressions , both read input by default
from stdin, and both output to
stdout. These are well-behaved UNIX tools,
and they work together well. The output from one can be piped
into the other, and their combined capabilities give shell
scripts some of the power of Perl.
 | One important difference between the utilities is
that while shell scripts can easily pass arguments to sed, it
is more complicated for awk (see Example 33-5
and Example 9-23).
|
