diff-logs

A command-line utility for diff'ing log files.

Quickly find diffing lines in all kinds of logs, namely build/CI logs, server/container logs or any such. Figure out why exactly the shit is failing quickly.

The script works by replacing common stochastic string patterns, such as datetime timestamps, download speeds, temporary files, HTTP header values, UUIDs, hash digests etc., with known fixed values that a tool such as diff can then easily skip.

Installation

First, check if your OS distro already provides an installable diff-logs package.

Otherwise:

1. Star, download or clone repo.
2. (Optional) Create a symlink in your bin-dir pointing to diff-logs shell script:

   mkdir -p ~/.local/bin
   export PATH="~/.local/bin:$PATH"    # Also put in .bashrc or similar
   # Link script into your bin
   ln -s ~/path/to/diff-logs/diff-logs ~/.local/bin/diff-logs

Usage

$ diff-logs --help

Usage: diff-logs < FILE1.log           # Print log file diff-friendly
       diff-logs FILE1.log FILE2.log   # Invoke $DIFFTOOL (e.g. diff)

Examples

Diff two log files

diff-logs FILE1 FILE2    # Invokes `diff`
# or
export DIFFTOOL=meld
diff-logs FILE1 FILE2    # Invokes `meld`

Diff-friendly-format a single log file

diff-logs < FILE1 > FILE1.clean

---

Finally, we can diff our logs with ease! 🥳

Improvements welcome!