‘less’ is a great tool for browsing Rails log files, though you might not guess it if you try to view your “development.log” with it.
Take the colour back
Rails writes xterm control characters into log files to colour
them. Usually ‘less’ escapes those characters, leading to an ugly
display – run
less -R to stop this escaping, allowing you to browse
log files in glorious technicolour. (Set your $LESS environment
variable to “-R” to make this the default.)
Follow the end of the log file
Shift-g will take you to the bottom of the log files (Use
less then pauses while calculating line numbers in a very large file).
Shift-F makes less work like
tail -f – it watches the end of the
file for new data.
Search for phrases or pesky backtraces
/ to search forwards, and
? to search backwards.
To find the last Ruby stack trace in a log file, open the logfile in
Shift-g to the end of the file, then search backwards using
“?`” (backtick) – usually backticks are only found in Ruby
stacktraces, at least if you’re not using mysql.