2020-02-22 NOTE: Looks like Go stopped putting the source file under $HOME/go/src. Without it, the external subcommands like zenlog init, etc will not work To make it work again, follow the new install instructions below...

Zenlog wraps a login shell and automatically saves all the output of each command to a separate log file, along with metadata such as each command start/finish time, the current directory, etc.

It has various applications:

• Want to open the output of the last command in my faviroite editor!

  • With the default installation you can do it with simply pressing ALT 1 on the command line.

• "What was the output of lsusb command I ran a month ago?"

  • Zenlog keeps log files in such a way that it's easy to find out a specific output, with meta-information such as the directory it was executed in, the git branch, the execution time, etc.

• The previous command output had an HTTP link. I want to open it in the browser.

  • Zenlog provides various commands to access the output of previous commands, to help write a script like this.

The primary target shell is Bash 4.4 or later (Zenlog requires the PS0 (aka preexec) hook added in Bash 4.4), but any shell with similar syntax with a pre-exec hook should work with zenlog. It comes with an installation script that supports both Bash and Zsh.

See the readme of the old version.

Zenlog uses the same idea as the previous perl/ruby versions, but is a complete write in Go, and no longer relies on script(1), and instead it'll create a PTY by itself.

To install, set up the Go SDK and follow the below instructions:

The go get method probably won't work anymore because it won't download the source file into $HOME/go/src. So now instead, you'll need to download the source file manually with git clone, and run scripts/install.sh, and set $ZENLOG_SRC_DIR to $HOME/src/zenlog/. Example:

mkdir $HOME/src
cd $HOME/src
git clone https://github.com/omakoto/zenlog.git
./zenlog/scripts/install.sh

... And add export ZENLOG_SRC_DIR=$HOME/src/zenlog/ to your .*shrc.

Then, run the following command to create ~/.zenlog.toml and update .bashrc (or .zshrc):

zenlog init

Then, start a new zenlog session by running:

zenlog

Then, try running ls -l and then press ALT 1. The output of the ls command should open in less. (If the hotkey doesn't work, then run zenlog open-last-log instead.)

• ~/.zenlog.toml contains various configuration such as the log directory.

• Set $ZENLOG_VIEWER and $ZENLOG_RAW_VIEWER to change what command to use to open log files. Set it in .bashrc / .zshrc.

• Create .zenlog.toml in your home directory:

cp "$(zenlog zenlog-src-top)/dot_zenlog.toml" "$HOME/.zenlog.toml"

• Then, if you're using Bash, add the following line to your ~/.bashrc.

. <(zenlog basic-bash-setup)

• Then, if you're using Zsh, add it to your ~/.zrc.

. <(zenlog basic-zsh-setup)

Any shell should work, as long as it supports some sort of "pre-exec" and "post-exec" hooks.

• Look at the output of zenlog basic-bash-setup and figure it out.

(However if your shell's command line syntax is far from Posix shell's, then Zenlog may not be able to extract command names property and you may not get "per command" output links.)

By default, log files are stored in $HOME/zenlog/, with the following structure:

  --SAN/ # "Sanitized" log -- outout with ESC sequences removed, for easy grepping.
 |   --YEAR
 |      --MONTH
 |         --DAY
 |            --log files...
 | 
  --RAW/ # "Raw", or the original output
 |   --YEAR... (same structure)
 |
  --ENV/ # "Env", or metadata.
 |   --YEAR... (same structure)
 |
  --cmds/ # Per command output.
 |   --cat
 |  |   --SAN
 |  |  |   --YEAR... (same structure)
 |  |   --RAW
 |  |   --ENV
 |  |  |--S  # This link contains the last sanitized output from cat(1).
 |  |  |--SS
 |  |  |--...
 |  |  |--R
 |  |  |--RR
 |  |  |--...
 |  |  |--E
 |  |  |--EE
 |  |  |--...
 |  |  
 |   --ls
 |  :
 | 
  --pids/  # Per-pid, or "session", output.
 |    (same strucute)
 | 
  --tags/  # Per "tag" output.
 |    (same strucute)
 | 
 |--S  # Link to the last command output.
 |--SS # Link to the second last command output.
 |--...
 |--R
 |--RR
 |--...
 |--E
 |--EE
 |--...
 

• "RAW" log files contain the original output, including all the escape sequences. It's authentic but hard to grep.

• "SAW" log files contain the original output with escape sequences stripped out, so easy to grep. (Note Zenlog only recognizes often-used escape sequences. Uncommon escape sequences may still be left.)

• "ENV" log files contain various meta inforamtion such as the current directory, execution time, git branch, etc.

• "S" is a symbolic link to the most recent SAN log file. "R" for RAW, "E" for ENV.

• "SS", "RR", "EE" are links to the second most log files.

• Zenlog also creates symbolic links for each command and "sessions". For example "$ZENLOG_DIR/pids/$ZENLOG_PID/S" is a link to the most recent SAN log file on the current shell. Conversely, "$ZENLOG_DIR/S" is the most recent command, which may be from a different shell.

If you run a command with a comment, for example:

$ make -B # full build 

then Zenlog creates symbolic links in the tags/ directory too, so $ZENLOG_DIR/tags/full_build/S will be a symbolic link to the most recent "full build" output.

• If you do not want to log output of a specific command (e.g. it doesn't really make sense to keep all output from vi, emacs), you can specify it in ~/.zenlog.toml.

  • By default, output from any zenlog subcommands will not be saved.

• zenlog purge-log [-p DAYS] [-y] [-P]

  • Removes all log files older than DAYS days.

    -y to execute without a [y/n] prompt.

    -P for dry-run.

• zenlog du [du(1) options]

  • Run du(1) over the log directory.

• zenlog history [-e] [-r] [-n Nth] [-p PID]

  • Print recent log file names.

    -e to show the ENV log file name instead of SAN.

    -r to show the RAW log file name instead of SAN.

    -n Nth Show Nth most recent log file name.

    • Note: When you're using this command from a script, the previous command output is -n 1. But if you're using zenlog history from a command that's bound to a hot key on the command line, -n 0 refers to the the previous output.

• See this directory for more (external) subcommands. This file contains more "buildin" subcommands.

See also the readme of the old version.