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Chapter 5. Command Line Tools

This section describes the behavioral changes of command-line tools in Red Hat Enterprise Linux 6.

5.1. Grep

The behavior of the grep command has changed with regards to searching for upper and lower case strings. Using interval searching in the [a-z] format is dependent on the LC_COLLATE variable.
You can set LC_COLLATE=C to preserve old behavior and to achieve proper results when performing interval searching with this method; however, in Red Hat Enterprise Linux 6, the recommended way of interval searching is to use the [[:lower:]],[[:upper:]] format.
This change can significantly affect output, so scripts and processes must be reviewed to continue to achieve the correct results.