/cpp_properties

c++ parser of the java properties syntax

Primary LanguageC++Boost Software License 1.0BSL-1.0

License Linux builds Mac builds Windows builds

cpp_properties

This library provides a complete lexer to produce a property abstract syntax tree according to the java properties grammar (https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html).

Basic usage

basic_usage.cpp

#include <cpp_properties/action/properties_action.hpp>
#include <cpp_properties/actor/properties_actor.hpp>
#include <cpp_properties/actor/traits/properties_actor_traits.hpp>
#include <cpp_properties/parser.hpp>
#include <map>

static const std::string DEFAULT_PROPERTIES = R"(
## message queue type (REDIS,MQTT)
mq.implType=MQTT
## connect host
mq.connect.host=127.0.0.1
## connect port
mq.connect.port=1883
## user name for connections
# mq.connect.username=
##password for connections
# mq.connect.password=
## timeout (milliseconds)
# mq.connect.timeout_ms=
## max count of reconnection
# mq.connect.max_reconnects=
## interval of reconnection (milliseconds)
# mq.connect.reconnect_interval_ms=
)";

 /*
  * the main function parses the given properties string into a
  * std::map<std::string, std::string>. Successfully extraction
  * displays '<key>=<value>' pairs to the console
  */
int main(int argc, char* argv[])
{
  std::map<std::string, std::string> cpp_properties;
  auto success = cpp_properties::parse(DEFAULT_PROPERTIES.begin(), DEFAULT_PROPERTIES.end(), cpp_properties);
  
  if (!success) {
      std::cout << "Lexical analysis failed" << std::endl;
      return 1;
  }
  
  // print key, value pairs
  for (auto p : cpp_properties) {
      std::cout << p.first << '=' << p.second << std::endl;
  }

  return 0;
}

build the source:

g++ -o cpp_properties_basic_usage -std=c++11 -I ${BOOST_INCLUDE_DIR} -I ${CPP_PROPERTIES_DIR}/src/include -Wno-deprecated-declarations basic_usage.cpp

run executable program cpp_properties_basic_usage, console output:

./cpp_properties_basic_usage
mq.connect.host=127.0.0.1
mq.connect.port=1883
mq.implType=MQTT

Overview

Many more examples are availables in Example directory. It shows how to parse following valid java property file in different structures:

#==============================================================================
# Copyright (c) 2015-2021 glywk
# https://github.com/glywk
# 
# Distributed under the Boost Software License, Version 1.0. (See accompanying
# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#==============================================================================

# This file aim to demonstrate ail crazy properties definition allowed by the
# java properties format details can be found at
# https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html

# =============================================================================
# The following part illustrates many allowed comment syntax
# =============================================================================

! -----------------------------------------------------------------------------
  # Comment line can start with '#'
  ! Comment line can start with '!'
  # Comment cannot use breaking line escape sequence \
    comment.break.line.should.not.hide.this.key1
  ! Comment cannot use breaking line escape sequence \
    comment.break.line.should.not.hide.this.key2
! -----------------------------------------------------------------------------

# =============================================================================
# The following part illustrates many allowed key syntax
# =============================================================================

! -----------------------------------------------------------------------------
! Simple key
! -----------------------------------------------------------------------------
simple

! -----------------------------------------------------------------------------
! Prefix / postfix key blanks are trimmed
! -----------------------------------------------------------------------------
  trim.key1 
  trim.key2  value 2
  trim.key3: 
  trim.key4: value 4
  trim.key5=
  trim.key6= value 6

! -----------------------------------------------------------------------------
! Break line space are ignored in key construction
! -----------------------------------------------------------------------------
no.\
   blank.\
         in.\
            this.\
          \"\
        key\
      \"\
.

! -----------------------------------------------------------------------------
! Break line in key with comment emulation
! -----------------------------------------------------------------------------
following.lines.includes.comment.syntax.in.a.key\
!--exclamation_comment_style--\
#--sharp_comment_style--\

! -----------------------------------------------------------------------------
! Simple key with escape chars
! -----------------------------------------------------------------------------
simple\ \=>\ escaped\:\
             {\\t\=>[\t]}\
             {\\n\=>[\n]}\
             {\\r\=>[\r]}\
             {\\f\=>[\f]},\
           \ not_escaped\:\
             {\\\\\=>[\\]}\
             {\\0\=>[\0]}\
             {\\'\=>[\']}\
             {\\"\=>[\"]}\
             {\\/\=>[\/]}\
             {\\v\=>[\v]}\
             {\\a\=>[\a]}\
             {\\b\=>[\b]}\
             {\\127\=>[\127]}

! -----------------------------------------------------------------------------
! Simple key with iso 8859-1 specific chars
! -----------------------------------------------------------------------------
latin1.key.\\u00E9.expect.display(é).as.(\u00E9)
latin1.key.\\u00E9.expect.display.escaped(\é).as.(\u00E9) 
 
! -----------------------------------------------------------------------------
! Simple key with unicode chars
! -----------------------------------------------------------------------------
simple.unicode.char_16.smileys\ \u263a[\\u263a],\u263B[\\u263B]
simple.unicode.char_16.smi1eys.and.chars\ \u263a0[\\u263a]0,\u263B0[\\u263B]0
simple.unicode.escape.is.case.sensitive\ \U263a[\\U263a],\U263B[\\U263B]

! -----------------------------------------------------------------------------
! Next duplicated key definition is ignored
! -----------------------------------------------------------------------------
duplicated.key = first declaration
duplicated.key = ignored declaration

# =============================================================================
# The following part illustrates many allowed separator syntax
# =============================================================================

! -----------------------------------------------------------------------------
! Key-value separated by blank chars
! -----------------------------------------------------------------------------
blank.separated1	value1
blank.separated2	\
                	value2
blank.separated3	value3

! -----------------------------------------------------------------------------
! Key-value separated by colon char
! -----------------------------------------------------------------------------
colon.separated1:value1
colon.separated2 :value2
colon.separated3 : value3
colon.separated4\
                 :value4
colon.separated5\
:\
value5
colon.separated6::value6.include.colon:
colon.separated7=\
:value7.break.line.before.include.colon:
colon.separated8:=value8.include.equals=
colon.separated9=\
=value9.break.line.before.include.equals=
colon.separated10 \
:=: value10.include.separator.chars :=
:

! -----------------------------------------------------------------------------
! Key-value separated by equal char
! -----------------------------------------------------------------------------
equal.separatedl=valuel
equal.separated2 =value2 
equal.separated3 = value3
equal.separated4\
                =value4
equal.separated5\
=\
value5
equal.separated6=:value6.include.colon:
equal.separated7=\
:value7.break.line.before.include.colon:
equal.separated8==value8.include.equals=
equal.separated9=\
=value9.break.line.before.include.equals=
equal.separated10 \
=:= value10.include.separator.chars =:
=

# =============================================================================
# The following part illustrates many allowed value syntax
# =============================================================================

! -----------------------------------------------------------------------------
! The most simple value (empty)
! -----------------------------------------------------------------------------
empty.key1
empty.key2:
empty.key3=

! -----------------------------------------------------------------------------
! Beginning blank value is trimmed
! -----------------------------------------------------------------------------
blank.key1
blank.key2  value 2
blank.key3:
blank.key4: value 4
blank.key5=
blank.key6= value 6

! -----------------------------------------------------------------------------
! Break line space are ignored in value construction
! -----------------------------------------------------------------------------
broken.line.in.value=\
no.\
   blank.\
         in.\
            this.\
          \"\
      value\
    \"\
.

! -----------------------------------------------------------------------------
! Break line in value with comment emulation
! -----------------------------------------------------------------------------
following.lines.includes.comment.syntax.in.a.value \
!--exclamation_comment_style--\
#--sharp_comment style--\

! -----------------------------------------------------------------------------
! Value with escape chars
! -----------------------------------------------------------------------------
escape.value \=> escaped:\
             {\\t\=>[\t]}\
             {\\n\=>[\n]}\
             {\\r\=>[\r]}\
             {\\f\=>[\f]}, \
             not_escaped:\
             {\\\\\=>[\\]}\
             {\\0\=>[\0]}\
             {\\'\=>[\']}\
             {\\"\=>[\"]}\
             {\\/\=>[\/]}\
             {\\v\=>[\v]}\
             {\\a\=>[\a]}\
             {\\b\=>[\b]}\
             {\\l27\=>[\127]}

! -----------------------------------------------------------------------------
! Simple value with iso 8859-1 specific chars
! -----------------------------------------------------------------------------
latin1.value \\u00E9.expect.display(é).as.(\u00E9)
latin1.value \\u00E9.expect.display.escaped(\é).as.(\u00E9) 

! -----------------------------------------------------------------------------
! Simple value with unicode chars
! -----------------------------------------------------------------------------
value.unicode.char_16.smileys \u263a[\\u263a],\u263B[\\u263B]
value.unicode.char_16.smileys.and.chars \u263a0[\\u263a]0,\u263B0[\\u263B]0
value.unicode.escape.is.case.sensitive \U263a[\\U263a],\U263B[\\U263B]

# =============================================================================
# The following part illustrates key syntax without end of line
# =============================================================================

! -----------------------------------------------------------------------------
! Key without end of line
! -----------------------------------------------------------------------------
single.key

have to be understand as:

comment.break.line.should.not.hide.this.key1=
comment.break.line.should.not.hide.this.key2=
simple=
trim.key1=
trim.key2=value 2
trim.key3= 
trim.key4= value 4
trim.key5=
trim.key6= value 6
no.blank.in.this."key".=
following.lines.includes.comment.syntax.in.a.key!--exclamation_comment_style--#--sharp_comment_style--=
simple => escaped:{\t=>[	]}{\n=>[
]}{\f=>[
        ]}, not_escaped:{\\=>[\]}{\0=>[0]}{\'=>[']}{\"=>["]}{\/=>[/]}{\v=>[v]}{\a=>[a]}{\b=>[b]}{\127=>[127]}=
latin1.key.\u00E9.expect.display(é).as.(é)=
latin1.key.\u00E9.expect.display.escaped(é).as.(é)=
simple.unicode.char_16.smileys ☺[\u263a],☻[\u263B]=
simple.unicode.char_16.smi1eys.and.chars ☺0[\u263a]0,☻0[\u263B]0=
simple.unicode.escape.is.case.sensitive U263a[\U263a],U263B[\U263B]=
duplicated.key= first declaration
duplicated.key= have to be ignored declaration
blank.separated1=value1
blank.separated2=value2
blank.separated3=value3
colon.separated1=value1
colon.separated2=value2
colon.separated3= value3
colon.separated4=value4
colon.separated5=value5
colon.separated6=:value6.include.colon:
colon.separated7=:value7.break.line.before.include.colon:
colon.separated8==value8.include.equals=
colon.separated9==value9.break.line.before.include.equals=
colon.separated10==: value10.include.separator.chars :=
=
equal.separated1=value1
equal.separated2=value2 
equal.separated3= value3
equal.separated4=value4
equal.separated5=value5
equal.separated6=:value6.include.colon:
equal.separated7=:value7.break.line.before.include.colon:
equal.separated8==value8.include.equals=
equal.separated9==value9.break.line.before.include.equals=
equal.separated10=:= value10.include.separator.chars =:
=
empty.key1=
empty.key2=
empty.key3=
blank.key1=
blank.key2=value 2
blank.key3=
blank.key4= value 4
blank.key5=
blank.key6= value 6
broken.line.in.value=no.blank.in.this."value".
following.lines.includes.comment.syntax.in.a.value=!--exclamation_comment_style--#--sharp_comment style--
escape.value==> escaped:{\t=>[	]}{\n=>[
]}{\f=>[
        ]}, not_escaped:{\\=>[\]}{\0=>[0]}{\'=>[']}{\"=>["]}{\/=>[/]}{\v=>[v]}{\a=>[a]}{\b=>[b]}{\l27=>[127]}
latin1.value=\u00E9.expect.display(é).as.(é)
latin1.value=\u00E9.expect.display.escaped(é).as.(é)
value.unicode.char_16.smileys=☺[\u263a],☻[\u263B]
value.unicode.char_16.smileys.and.chars=☺0[\u263a]0,☻0[\u263B]0
value.unicode.escape.is.case.sensitive=U263a[\U263a],U263B[\U263B]
single.key=

Compiling

cmake supports 'out of source' builds by default, to use it do this:

mkdir build
cd build
cmake ..
make

this should create everything into the build/ directory

Test

Run the cpp_properties test suites. This is covered by cmake:

make test