What is the easiest way to parse an INI File in C

Question

I m trying to parse an INI file using C    Any tips on what is the best way to achieve this  Should I use the Windows API tools for INI file processing  with which I am totally unfamiliar   an open-source solution or attempt to parse it manually

User · Answer

inih is a simple ini parser written in C, it comes with a C++ wrapper too. Example usage:

#include "INIReader.h"    

INIReader reader("test.ini");

std::cout << "version="
          << reader.GetInteger("protocol", "version", -1) << ", name="
          << reader.Get("user", "name", "UNKNOWN") << ", active="
          << reader.GetBoolean("user", "active", true) << "\n";

The author has also a list of existing libraries here.

User · Answer

I ended up using inipp which is not mentioned in this thread   https   github com mcmtroffaes inipp  Was a MIT licensed header only implementation which was simple enough to add to a project and 4 lines to use

User · Answer

Maybe a late answer  But  worth knowing options  If you need a cross-platform solution   definitely you can try GLIB   its interesting    https   developer gnome org glib stable glib-Key-value-file-parser html

User · Answer

Unless you plan on making the app cross-platform  using the Windows API calls would be the best way to go  Just ignore the note in the API documentation about being provided only for 16-bit app compatibility

User · Answer

I know this question is very old  but I came upon it because I needed something cross platform for linux  win32    I wrote the function below  it is a single function that can parse INI files  hopefully others will find it useful   rules  amp  caveats   buf to parse must be a NULL terminated string  Load your ini file into a char array string and call this function to parse it  section names must have    brackets around them  such as this  MySection   also values and sections must begin on a line without leading spaces  It will parse files with Windows  r n or with Linux  n line endings  Comments should use   or    and begin at the top of the file  no comments should be mixed with INI entry data  Quotes and ticks are trimmed from both ends of the return string  Spaces are only trimmed if they are outside of the quote  Strings are not required to have quotes  and whitespaces are trimmed if quotes are missing  You can also extract numbers or other data  for example if you have a float just perform a atof ret  on the ret buffer       -----note  no escape is nessesary for inner quotes or ticks-----     -----------------------------example----------------------------      Entry2      Alignment     1     LightLvl 128     Library       5555     StrValA    Inner  quoted  or  quoted  strings are ok to use     StrValB     This a  quoted  or  quoted  String Value      StrValC     This a  tick  or  tick  String Value      StrValD     Missing quote at end will still work     StrValE    This is another  quote  example     StrValF       Spaces inside the quote are preserved       StrValG    This works too and spaces are trimmed away     StrValH       ----------------------------------------------------------------   12oClocker super lean and mean INI file parser  with section support    set section to 0 to disable section support   returns TRUE if we were able to extract a string into ret value   NextSection is a char  pointer  will be set to zero if no next section is found   will be set to pointer of next section if it was found    use it like this    char  NextSection   0   GrabIniValue X X X X X  amp NextSection     buf is data to parse  ret is the user supplied return buffer BOOL GrabIniValue char  buf  const char  section  const char  valname  char  ret  int retbuflen  char   NextSection        if  buf   ret 0  return FALSE        char  s   buf    search starts at  s  pointer     char  e   0      end of section pointer        find section     if section                int L   strlen section           SearchAgain1          s   strstr s section   if  s   ret 0  return FALSE        find section         if s  gt  buf  amp  amp     s-1      n   s  L  goto SearchAgain1     section must be at begining of a line          s  L                                                      found section  skip past section name         while  s    n   s     s                                   spin until next line  s is now begining of section data         e   strstr s   n                                          find begining of next section or end of file         if e   e 0                                                if we found begining of next section  null the  n so we don t search past section         if NextSection                                            user passed in a NextSection pointer           if e   NextSection  e 1   else  NextSection 0           set pointer to next section              restore char at end of section  ret empty string  return FALSE      define RESTORE E     if e   e   n         define SAFE RETURN   RESTORE E     ret  0   return FALSE        find valname     int L   strlen valname       SearchAgain2      s   strstr s valname   if  s  SAFE RETURN                 find valname     if s  gt  buf  amp  amp     s-1      n   s  L  goto SearchAgain2     valname must be at begining of a line      s  L                                                      found valname match  skip past it     while  s          s      t   s                            skip spaces and tabs     if    s   SAFE RETURN                                     if NULL encounted do safe return     if  s         goto SearchAgain2                           no equal sign found after valname  search again     s                                                         skip past the equal sign     while  s           s    t   s                             skip spaces and tabs     while  s           s        s                             skip past quotes and ticks     if    s   SAFE RETURN                                     if NULL encounted do safe return     char  E   s                                               s is now the begining of the valname data     while  E    r   amp  amp   E    n   amp  amp   E  0  E     E--            find end of line or end of string  then backup 1 char     while E  gt  s  amp  amp    E          E    t    E--                 move backwards past spaces and tabs     while E  gt  s  amp  amp    E           E         E--                move backwards past quotes and ticks     L   E-s 1                                                 length of string to extract NOT including NULL     if L lt 1    L 1  gt  retbuflen  SAFE RETURN                    empty string or buffer size too small     strncpy ret s L                                           copy the string     ret L  0                                                  null last char on return buffer     RESTORE E      return TRUE        undef RESTORE E      undef SAFE RETURN     How to use    example      char sFileData       MySection  r n   MyValue1   123 r n   MyValue2   456 r n   MyValue3   789 r n    r n    MySection  r n   MyValue1   Hello1 r n   MyValue2   Hello2 r n   MyValue3   Hello3 r n    r n   char str 256   char  sSec   sFileData  char secName       MySection      we support sections with same name while sSec   while we have a valid sNextSec         print values of the sections     char  next 0   in case we dont have any sucessful grabs     if GrabIniValue sSec secName  MyValue1  str sizeof str   amp next     printf  MyValue1     s  n  str         if GrabIniValue sSec secName  MyValue2  str sizeof str  0         printf  MyValue2     s  n  str         if GrabIniValue sSec secName  MyValue3  str sizeof str  0         printf  MyValue3     s  n  str         printf   n        sSec   next    parse next section  next will be null if no more sections to parse

User · Answer

If you are interested in platform portability  you can also try Boost PropertyTree  It supports ini as persistancy format  though the property tree my be 1 level deep only

User · Answer

If you are already using Qt  QSettings my settings  filename ini   QSettings  IniFormat     Then read a value  my settings value  GroupName ValueName    lt  lt DEFAULT VAL gt  gt   toInt     There are a bunch of other converter that convert your INI values into both standard types and Qt types  See Qt documentation on QSettings for more information

User · Answer

I have never parsed ini files  so I can t be too specific on this issue  But i have one advice  Don t reinvent the wheel as long as an existing one meets your requirements  http   en wikipedia org wiki INI file Accessing INI files http   sdl-cfg sourceforge net  http   sourceforge net projects libini  http   www codeproject com KB files config-file-parser aspx  Good luck

User · Answer

You can use the Windows API functions  such as GetPrivateProfileString   and GetPrivateProfileInt

User · Answer

this question is a bit old  but I will post my answer  I have tested various INI classes  you can see them on my website  and I also use simpleIni because I want to work with INI files on both windows and winCE  Window s GetPrivateProfileString   works only with the registry on winCE   It is very easy to read with simpleIni  Here is an example    include  SimpleIni SimpleIni h      CSimpleIniA ini  ini SetUnicode    ini LoadFile FileName   const char   pVal   ini GetValue section  entry  DefaultStr

User · Answer

If you need a cross-platform solution  try Boost s Program Options library

User · Answer

Have you tried libconfig  very JSON-like syntax  I prefer it over XML configuration files

User · Answer

I use SimpleIni  It s cross-platform

[c++] What is the easiest way to parse an INI File in C++?

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