How do I grab an INI value within a shell script?

Question

How about grepping for that line then using awk

version=$(awk -F "=" '/database_version/ {print $2}' parameters.ini)

You can use bash native parser to interpret ini values, by:

$ source <(grep = file.ini)

Sample file:

[section-a]
  var1=value1
  var2=value2
  IPS=( "1.2.3.4" "1.2.3.5" )

To access variables, you simply printing them: echo $var1. You may also use arrays as shown above (echo ${IPS[@]}).

If you only want a single value just grep for it:

source <(grep var1 file.ini)

^{For the demo, check this recording at asciinema.}

It is simple as you don't need for any external library to parse the data, but it comes with some disadvantages. For example:

• If you have spaces between = (variable name and value), then you've to trim the spaces first, e.g.

    $ source <(grep = file.ini | sed 's/ *= */=/g')
  

  Or if you don't care about the spaces (including in the middle), use:

    $ source <(grep = file.ini | tr -d ' ')
  

• To support ; comments, replace them with #:

    $ sed "s/;/#/g" foo.ini | source /dev/stdin
  

• The sections aren't supported (e.g. if you've [section-name], then you've to filter it out as shown above, e.g. grep =), the same for other unexpected errors.

  If you need to read specific value under specific section, use grep -A, sed, awk or ex).

  E.g.

    source <(grep = <(grep -A5 '\[section-b\]' file.ini))
  

  ^{Note: Where -A5 is the number of rows to read in the section. Replace source with cat to debug.}

• If you've got any parsing errors, ignore them by adding: 2>/dev/null

See also:

• How to parse and convert ini file into bash array variables? at serverfault SE
• Are there any tools for modifying INI style files from shell script

Sed one-liner, that takes sections into account. Example file:

[section1]
param1=123
param2=345
param3=678

[section2]
param1=abc
param2=def
param3=ghi

[section3]
param1=000
param2=111
param3=222

Say you want param2 from section2. Run the following:

sed -nr "/^\[section2\]/ { :l /^param2[ ]*=/ { s/.*=[ ]*//; p; q;}; n; b l;}" ./file.ini

will give you

def

Bash does not provide a parser for these files. Obviously you can use an awk command or a couple of sed calls, but if you are bash-priest and don't want to use any other shell, then you can try the following obscure code:

#!/usr/bin/env bash
cfg_parser ()
{
    ini="$(<$1)"                # read the file
    ini="${ini//[/\[}"          # escape [
    ini="${ini//]/\]}"          # escape ]
    IFS=$'\n' && ini=( ${ini} ) # convert to line-array
    ini=( ${ini[*]//;*/} )      # remove comments with ;
    ini=( ${ini[*]/\    =/=} )  # remove tabs before =
    ini=( ${ini[*]/=\   /=} )   # remove tabs after =
    ini=( ${ini[*]/\ =\ /=} )   # remove anything with a space around =
    ini=( ${ini[*]/#\\[/\}$'\n'cfg.section.} ) # set section prefix
    ini=( ${ini[*]/%\\]/ \(} )    # convert text2function (1)
    ini=( ${ini[*]/=/=\( } )    # convert item to array
    ini=( ${ini[*]/%/ \)} )     # close array parenthesis
    ini=( ${ini[*]/%\\ \)/ \\} ) # the multiline trick
    ini=( ${ini[*]/%\( \)/\(\) \{} ) # convert text2function (2)
    ini=( ${ini[*]/%\} \)/\}} ) # remove extra parenthesis
    ini[0]="" # remove first element
    ini[${#ini[*]} + 1]='}'    # add the last brace
    eval "$(echo "${ini[*]}")" # eval the result
}

cfg_writer ()
{
    IFS=' '$'\n'
    fun="$(declare -F)"
    fun="${fun//declare -f/}"
    for f in $fun; do
        [ "${f#cfg.section}" == "${f}" ] && continue
        item="$(declare -f ${f})"
        item="${item##*\{}"
        item="${item%\}}"
        item="${item//=*;/}"
        vars="${item//=*/}"
        eval $f
        echo "[${f#cfg.section.}]"
        for var in $vars; do
            echo $var=\"${!var}\"
        done
    done
}

Usage:

# parse the config file called 'myfile.ini', with the following
# contents::
#   [sec2]
#   var2='something'
cfg.parser 'myfile.ini'

# enable section called 'sec2' (in the file [sec2]) for reading
cfg.section.sec2

# read the content of the variable called 'var2' (in the file
# var2=XXX). If your var2 is an array, then you can use
# ${var[index]}
echo "$var2"

Bash ini-parser can be found at The Old School DevOps blog site.

Just include your .ini file into bash body:

File example.ini:

DBNAME=test
DBUSER=scott
DBPASSWORD=tiger

File example.sh

#!/bin/bash
#Including .ini file
. example.ini
#Test
echo "${DBNAME}   ${DBUSER}  ${DBPASSWORD}"

All of the solutions I've seen so far also hit on commented out lines. This one didn't, if the comment code is ;:

awk -F '=' '{if (! ($0 ~ /^;/) && $0 ~ /database_version/) print $2}' file.ini

one of more possible solutions

dbver=$(sed -n 's/.*database_version *= *\([^ ]*.*\)/\1/p' < parameters.ini)
echo $dbver