Sometimes it's nice to have some coloring in your logs for better readability. You can output your logs via
tail
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and pipe this through
sed
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to add ANSI color annotations (which your console then interprets).
To print a log (e.g. rails log) and color all lines containing "FATAL" in red and all lines with "INFO" in green:
tail -f /path/to/log | sed --unbuffered -e 's/\(.*INFO.*\)/\o033[32m\1\o033[39m/' -e 's/\(.*FATAL.*\)/\o033[31m\1\o033[39m/'
Here are the most common color codes:
Color | Font | Background |
---|---|---|
Black | \033[30m | \033[40m |
Red | \033[31m | \033[41m |
Green | \033[32m | \033[42m |
Orange | \033[33m | \033[43m |
Blue | \033[34m | \033[44m |
Magenta | \033[35m | \033[45m |
Cyan | \033[36m | \033[46m |
Light gray | \033[37m | \033[47m |
Use default | \033[39m | \033[49m |
There are even more colors than this, see this epic SO answer for more details Show archive.org snapshot !
Important
Remember to restore the default color after the content you want colored.
As typing this is kind of cumbersome, you may want to add a bash alias Show archive.org snapshot .
Side note: if you have colored output and want to remove the color annotations, see this card