outcoldman
outcoldman Denis Gladkikh

DBHist: bash history in sqlite

sqlite, bash, terminal.app, and term

I spend a lot of time in terminals, as most of you. I never been more productive than when I started to use dbhist.

You probably know several ways how you can search bash history. My ways were Control-R or history | grep foo. Both have limitations, both has issues. With grep it always a hassle for me to write POSIX compatible regexp, like it always gets me, it should be [[:digit:]], not \d. And don’t want to mention how often bash corrupts or unexpectedly overrides history file, which I use one for all sessions.

Also remember the time when I kept huge cheatsheets with various commands. The main problems with that approach was - I needed another cheatsheet to remember that I had one, and they become outdated very quickly.

I am not the first one, who decided to use sqlite for storing bash history. I have seen some mentionin on web. I have found some very good implementations. But could not find anything I liked. Some were written in python (additional dependencies) or zsh (nice shell, used it for a while, but decided to stay with default), had dependencies on package managers, or other libraries (bash scripts). I really wanted something simple, something I could just put in my dotfiles repo and modify it when I need it.

So at the end I wrote my own implementation. You can find it on gist (also embedded below).

It has only one requirement, set HISTTIMEFORMAT="%s ". That tells bash to store commands in history with time in Unixtime format. After that source the file

$ source dbhist.sh

Update (2017-08-04): thanks to Johan Carlquist, we have a homebrew formula homebrew-dbhist. See How to Create and Maintain a Tap for installation instructions.

I have verified that it works with Bash 3.2 (default on macOS) and 4.x.

To get help

$ dbhist --help

To start searching your history (it does not import your current bash history, so don’t be surprised, that it does not give you much at the beginning) just type

$ dbhist git

That only shows results for current session, if you want to search across all sessions

$ dbhist --all 'git status'
  8804 | 2017-07-19 07:52:49 |    373 | git status

I have typed git status 373 types from the time I started to use dbhist. It shows the last time I typed it in second column. The first column is just an incremental id of the last saved command.

You can see how often you pushed current git repository if you invoke this command from its folder

dbhist --all --under 'git push' 
  8770 | 2017-07-17 20:19:04 |     12 | git push

In this case --under means to show all commands executed in current folder or subfolder. You can also find commands executed only in current folder with --here. For example show me last 5 commands executed in home folder

$ dbhist --here --all --limit 5
  8843 | 2017-07-19 15:05:48 |      2 | cd 
  8814 | 2017-07-19 14:28:53 |      6 | cd .dotfiles
  8741 | 2017-07-17 11:55:44 |     17 | cd dev
  8740 | 2017-07-17 11:55:42 |     29 | ls
  8651 | 2017-07-17 11:55:42 |      9 | brew upgrade

And the most useful feature. For example I remember that to invalidate cloudfront distribution I use aws tool. And I remember that command has a word invalidation, so

$ dbhist --all --starts 'aws%invalidation'
  8531 | 2017-07-13 19:26:43 |      7 | aws cloudfront create-invalidation --distribution-id ERCTXXXKGZXX4 --paths "/*"
  6269 | 2017-06-30 13:19:06 |      3 | aws cloudfront create-invalidation help
  6268 | 2017-06-30 13:18:56 |      1 | aws cloudfront get-invalidation --distribution-id ERCTXXXGZSH4 --id I2XXXXKXU3991
  6266 | 2017-06-30 13:17:40 |      1 | aws cloudfront create-invalidation --distribution-id ERCTXXXKGZXX4
  6262 | 2017-06-30 12:48:25 |      1 | aws cloudfront list-invalidations --distribution-id ERCTZXXXGZXX4

Where % is a SQL syntax, similar to globbing pattern Wildcards. Parameter --starts tells to search only when command starts from the aws..., by default dbhist searches with pattern %query%, which means that query can be anywhere.

Hope you can also find it useful.

Below is the listing of dbhist.sh, you can also find it on gist.github.com.

# The MIT License
# SPDX short identifier: MIT

# Further resources on the MIT License
# Copyright 2017 Denis Gladkikh (https://www.outcoldman.com/en/archive/2017/07/19/dbhist/)

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

################################################################################

# To use it, just source the file `source dbhist.sh`
# Verified that works with Bash 3/4

# Configuration
#   DBHISTORY=true - use false to disable 
#   DBHISTORYFILE=$HOME/.dbhist - location of dbhist file
# 
# To make it work I keep next configuration for bash, the only important is the
# time format, to make it unixtime
#
#   HISTSIZE=$HOME/.bash_history
#   HISTFILESIZE=1000
#   HISTSIZE=1000
#   HISTTIMEFORMAT="%s "
#   HISTCONTROL=ignorespace:erasedups
#
# More details in https://www.outcoldman.com/en/archive/2017/07/19/dbhist/
# Or use after you sourced this file
#  dbhist --help

################################################################################

if ${DBHISTORY:-true}; then

# Kind of session ID, allows to see only commands executed in this terminal session
__dbhist_salt="${RANDOM}"
# This allows us to verify existence of .dbhist file only once
__dbhist_initialized=false
# Keep the previous folder, this how we keep the PWD for commands like `cd ...`
__dbhist_oldpwd="${OLDPWD}"

# Get location of .dbhist file, default location is under `$HOME/.dbhist`
__dbhist_file() {
  echo "${DBHISTORYFILE:-$HOME/.dbhist}"
}

# Execute command on sqlite with .dbhist file
__dbhist_sqlite() {
  sqlite3 "$(__dbhist_file)"
}

# Initialize dbhist file, create table
__db_hist_init() {
  if [[ ! -f "$(__dbhist_file)" ]]; then
    local __sql='CREATE TABLE history (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  hist_id INTEGER,
  cmd TEXT,
  epoch INTEGER,
  ppid INTEGER,
  pwd TEXT,
  salt INTEGER
);'
    echo "${__sql}" | __dbhist_sqlite
  fi
}

# Execute it with bash PROMPT
__db_hist_prompt() {
  if ! ${__dbhist_initialized}; then
    __db_hist_init
    __dbhist_initialized=true
    return
  fi

  if [[ -n "${COMP_LINE}" ]]; then
    return
  fi

  local __formated_history=
  local __num=
  local __epoch=
  local __pwd="${PWD}"
  if [[ "${OLDPWD}" !=  "${__dbhist_oldpwd}" ]]; then
    __pwd="${OLDPWD}"
    __dbhist_oldpwd="${OLDPWD}"
  fi
  #   521 1492964870 history 1
  __formated_history="$(history 1 | sed -E 's/[[:space:]]+([[:digit:]]+)[[:space:]]+([[:digit:]]+)[[:space:]](.+)/\1@\2@\3/')"
  __num="$(echo "${__formated_history}" | sed -E 's/([^@]+)@([^@]+)@(.+)/\1/')"
  __epoch="$(echo "${__formated_history}" | sed -E 's/([^@]+)@([^@]+)@(.+)/\2/')"
  __command="$(echo "${__formated_history}" | sed -E 's/([^@]+)@([^@]+)@(.+)/\3/')"
  __dbhist_sqlite <<-END
INSERT INTO history(hist_id, epoch, cmd, ppid, pwd, salt)
VALUES("${__num}", "${__epoch}", "${__command//\"/""}", ${PPID}, "${__pwd//\"/""}", ${__dbhist_salt});
END
  
}

# Use 
#   dbhist --help
# To learn the tool
dbhist() {
  local __limit=100
  local __all=false
  local __self=false
  local __starts=false
  local __verbose=false
  local __query=''
  local __location=''
  local __pwd=false
  while ! [[ $# -eq 0 || -z "${1}" ]]; do
    case "${1}" in
      (--shell)
        __dbhist_sqlite
        return
      ;;
      (--help)
        cat<<END
Usage:
  dbhist [options] [query]
Options:
  --limit {number}
    number of latest commands to show. Defaults to 100.
  --all
    include history of all sessions. Not only current.
  --self
    include history about dbhist
  --starts
    match only commands starts with query
  --verbose
    verbose output (shows sql)
  --here
    reduce search only for current pwd
  --under
    reduce search only for current and under pwd
  --pwd
    show working directory of cmd
  --shell
    access to shell
END
        return
      ;;
      (--limit)
        shift
        __limit="${1:?option require value}"
        if ! [[ "${__limit}" =~ ^[0-9]+$ ]]; then
         2>&1 echo "Limit should be a number"
         return 1
        fi
      ;;
      (--all)
        __all=true
      ;;
      (--self)
        __self=true
      ;;
      (--starts)
        __starts=true
      ;;
      (--verbose)
        __verbose=true
      ;;
      (--here)
        if [[ -n "${__location}" ]]; then
          2>&1 echo "Specifier for pwd already set"
          return 1
        fi
        __location="here"
      ;;
      (--under)
        if [[ -n "${__location}" ]]; then
          2>&1 echo "Specifier for pwd already set"
          return 1
        fi
        __location="under"
      ;;
      (--pwd)
        __pwd=true
      ;;
      (-*)
        2>&1 echo "Unknown option ${1}"
        return 1
      ;;
      (*)
        if [[ -n "${__query}" ]]; then
          2>&1 echo "Cannot specify more than one query"
          return 1
        fi
        __query="${1:?requires value}"
      ;;
    esac
    shift
  done
  __pwd_q=''
  if ${__pwd}; then
    __pwd_q='pwd || " > " ||'
  fi
  local __sql="
  SELECT 
    substr('      '||max(id),-6) || 
    ' | ' ||
    datetime(max(epoch), 'unixepoch', 'localtime') ||
    ' | ' ||
    substr('      '||count(*),-6) ||
    ' | ' ||
    ${__pwd_q}
    cmd
  FROM history
  WHERE 1 "
  if ! ${__all}; then
    __sql+="AND (salt=${__dbhist_salt} AND ppid=${PPID}) "
  fi
  if ! ${__self}; then
    __sql+="AND (cmd != 'dbhist' AND cmd NOT LIKE 'dbhist %') "
  fi
  if [[ -n "${__query}" ]]; then
    __query=${__query//\"/""}
    if ! ${__starts} && [[ "${__query}" != %* ]]; then
      __query="%${__query}"
    fi
    if [[ "${__query}" != *% ]]; then
      __query+="%"
    fi
    __sql+="AND cmd LIKE \"${__query}\" ESCAPE '\' "
  fi
  __pwd_l="${PWD//\"/""}"
  case "${__location}" in
    (here)
      __sql+="AND (pwd == \"${__pwd_l}\") "
    ;;
    (under)
      __pwd_l="${__pwd_l//%/\%}"
      __pwd_l="${__pwd_l//_/\_}"
      __sql+="AND (pwd LIKE \"${__pwd_l}%\" ESCAPE '\') "
    ;;
  esac
  __sql+="GROUP BY cmd "
  if ${__pwd}; then
    __sql+=", pwd "
  fi
  __sql+="ORDER BY max(id) DESC LIMIT ${__limit} ;"
  if ${__verbose}; then
    echo "database:"
    __dbhist_file
    echo "sql:"
    echo "${__sql}"
  fi
  echo "${__sql}" | __dbhist_sqlite
}

# Inject __db_hist_prompt in `PROMPT_COMMAND`
if ! [[ "${PROMPT_COMMAND}" =~ .*__db_hist_prompt.* ]]; then
  PROMPT_COMMAND="__db_hist_prompt${PROMPT_COMMAND:+; $PROMPT_COMMAND}"
fi

fi

Have feedback or questions? Looking for consultation?

My expertise: MongoDB, ElasticSearch, Splunk, and other databases. Docker, Kubernetes. Logging, Metrics. Performance, memory leaks.

Send me an email to public@denis.gladkikh.email.

The content on this site represents my own personal opinions and thoughts at the time of posting.

Content licensed under the Creative Commons CC BY 4.0.