README

retail - tail with regular expressions

retail can output that part of a file (or pipe) following the last
match of a regular expression, which can be useful for logfiles and
various other kinds of data. It is also a fully compliant
implementation of the POSIX.1-2008 tail command, so you can
theoretically replace your system tail with it. retail is GPL3.

To build:
  ./configure
  make
  make install (optionally)
By default, it installs into ~/.local/bin, but that can be changed
using ./configure --prefix=/path/here.

After that,
  retail -r REGEX FILE
will output that part of FILE starting at the last match of POSIX
extended regular expression REGEX. If -u REGEX2 is also given, it
will exit after outputting a line matching REGEX2. It also supports
the standard options to tail, along with some extensions.

Usage: ./retail [OPTION]... [FILE]
Print the last 10 lines of FILE to standard output.
If no FILE given or FILE is -, use standard input.

Options:
  -b         with -r, begin at first matching line, not last.
  -c N       print the last N bytes; -c +N will begin with
             the Nth byte
  -f         continue reading from file as data is appended
  -n N       output the last N lines; -n +N will begin with
             the Nth line
  -r REGEX   output lines beginning with last line matching
             extended regular expression REGEX
  -u REGEX   stop following file when a line matches extended
             regular expression REGEX, and exit.
  --help     display help and exit
  --version  display version information and exit

The -r and -u options take an extended POSIX regular expression as
argument. These expressions are matched against each line without
implicit anchoring. ^ and $ will match the start and end of a line
respectively. -u is meaningful only when joined with -f, and will
output the matching line before terminating.