Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

8.58. grep

Updated grep packages that fix several bugs are now available for Red Hat Enterprise Linux 6.
The grep utility searches through textual input for lines which contain a match to a specified pattern and then prints the matching lines. GNU grep utilities include grep, egrep and fgrep.

Bug Fixes

For some regular expressions, the DFA analysis could insert up to double "positions" than there were leaves. Consequently, there were not enough room to insert all the positions and grep could terminate unexpectedly on certain regular expressions. To fix this problem, space allocation has been increased and grep works as expected in the described scenario.
When a fixed string pattern was empty while the case-insensitive search was active, grep could terminate unexpectedly. With this update, the check for this case has been added to the code and grep works as expected in the described scenario.
Previously, the code handling case-insensitive searches could alter a string's byte size while converting it to lower case. Consequently, grep could truncate certain output strings. To fix this bug, the grep code has been modified to correctly handle such cases when the byte size gets altered during the conversion to lower case. As a result, case-insensitive searches work correctly and grep no longer truncates its output.
Users of grep are advised to upgrade to these updated packages, which fix these bugs.