/usr/share/doc/atftpd/pcre_pattern.txt is in atftpd 0.7.dfsg-11.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | ^[p]?pxelinux.cfg/[0-9A-F]{1,6}$ pxelinux.cfg/default
^[p]?pxelinux.0$ pxelinux.0
linux linux
^str$ replaced1
^str replaced2
str$ replaced3
repl(ace) m$1
^\w*\.conf$ master.conf
|