The T-Rex Regex Group Matcher

trex (pronounced t-rex) is a simple command-line utility that works similar to grep. The main difference is that it only shows the matching groups of a regular expressions.

This allows simple parsing out of values from text while still requiring more context than just the match of the value. While sed and awk can also do this, I never manage to remember the syntax.

This utility uses the UNIX/POSIX regex.h implementation of pattern matcher, therefore POSIX syntax applies for provided patterns.

Example

> echo "t=4.33 x=82 and d=99" | trex 'x=([0-9]*)'
82

As shown above, this makes parsing out values from files very simple.

Wishlist

• allow input of multiple files
• add -i flag for case insensitive matches (eflags)
• add -0 flag for \0 separated matches instead of ' '

Authors

• Thomas Richner