ini.cpp

Go to the documentation of this file.

/** \file ini.cpp
 * \author Jared R. Males
 * \brief Implementation of the The inih  ini-style, file parser modified for mxlib.
 *
 * \ingroup mxApp_files
 *
 */
 
#ifndef INI_COMMENT_CHAR
#define INI_COMMENT_CHAR ( '#' )
#endif
 
/* Nonzero to allow multi-line value parsing, in the style of Python's
   ConfigParser. If allowed, ini_parse() will call the handler with the same
   name for each subsequent line parsed. */
#ifndef INI_ALLOW_MULTILINE
#define INI_ALLOW_MULTILINE 1
#endif
 
/* Nonzero to allow a UTF-8 BOM sequence (0xEF 0xBB 0xBF) at the start of
   the file. See http://code.google.com/p/inih/issues/detail?id=21 */
#ifndef INI_ALLOW_BOM
#define INI_ALLOW_BOM 1
#endif
 
/* Nonzero to use stack, zero to use heap (malloc/free). */
#ifndef INI_USE_STACK
#define INI_USE_STACK 0
#endif
 
/* Stop parsing on first error (default is to stop parsing). */
#ifndef INI_STOP_ON_FIRST_ERROR
#define INI_STOP_ON_FIRST_ERROR 0
#endif
 
/* Maximum line length for any line in INI file. */
#ifndef INI_MAX_LINE
#define INI_MAX_LINE 1024
#endif
 
#define MAX_SECTION 50
#define MAX_NAME 50
 
#if !INI_USE_STACK
#include <stdlib.h>
#endif
 
#include "app/ini.hpp"
 
/* Strip whitespace chars off end of given string, in place. Return s. */
static char *rstrip( char *s )
{
    char *p = s + strlen( s );
    while( p > s && isspace( (unsigned char)( *--p ) ) )
        *p = '\0';
    return s;
}
 
/* Return pointer to first non-whitespace char in given string. */
static char *lskip( const char *s )
{
    while( *s && isspace( (unsigned char)( *s ) ) )
        s++;
    return (char *)s;
}
 
/* Return pointer to first char c or ';' comment in given string, or pointer to
   null at end of string if neither found. ';' must be prefixed by a whitespace
   character to register as a comment. */
static char *find_char_or_comment( const char *s, char c )
{
    int was_whitespace = 0;
    while( *s && *s != c && !( was_whitespace && *s == INI_COMMENT_CHAR ) )
    {
        was_whitespace = isspace( (unsigned char)( *s ) );
        s++;
    }
    return (char *)s;
}
 
/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
static char *strncpy0( char *dest, const char *src, size_t size )
{
    strncpy( dest, src, size );
    dest[size - 1] = '\0';
    return dest;
}
 
int ini_parse_file( FILE *file, int ( *handler )( void *, const char *, const char *, const char * ), void *user )
{
    /* Uses a fair bit of stack (use heap instead if you need to) */
#if INI_USE_STACK
    char line[INI_MAX_LINE];
#else
    char *line;
#endif
    char section[MAX_SECTION] = "";
    char prev_name[MAX_NAME] = "";
 
    char *start;
    char *end;
    char *name;
    char *value;
    int lineno = 0;
    int error = 0;
 
#if !INI_USE_STACK
    line = (char *)malloc( INI_MAX_LINE );
    if( !line )
    {
        return -2;
    }
#endif
 
    /* Scan through file line by line */
    while( fgets( line, INI_MAX_LINE, file ) != NULL )
    {
        lineno++;
 
        start = line;
#if INI_ALLOW_BOM
        if( lineno == 1 && (unsigned char)start[0] == 0xEF && (unsigned char)start[1] == 0xBB &&
            (unsigned char)start[2] == 0xBF )
        {
            start += 3;
        }
#endif
        start = lskip( rstrip( start ) );
 
        if( *start == INI_COMMENT_CHAR || *start == '#' )
        {
            /* Per Python ConfigParser, allow '#' comments at start of line */
        }
#if INI_ALLOW_MULTILINE
        else if( *prev_name && *start && start > line )
        {
            /* Non-black line with leading whitespace, treat as continuation
               of previous name's value (as per Python ConfigParser). */
            if( !handler( user, section, prev_name, start ) && !error )
                error = lineno;
        }
#endif
        else if( *start == '[' )
        {
            /* A "[section]" line */
            end = find_char_or_comment( start + 1, ']' );
            if( *end == ']' )
            {
                *end = '\0';
                strncpy0( section, start + 1, sizeof( section ) );
                *prev_name = '\0';
            }
            else if( !error )
            {
                /* No ']' found on section line */
                error = lineno;
            }
        }
        else if( *start && *start != INI_COMMENT_CHAR )
        {
            /* Not a comment, must be a name[=:]value pair */
            end = find_char_or_comment( start, '=' );
            if( *end != '=' )
            {
                end = find_char_or_comment( start, ':' );
            }
            if( *end == '=' || *end == ':' )
            {
                *end = '\0';
                name = rstrip( start );
                value = lskip( end + 1 );
                end = find_char_or_comment( value, '\0' );
                if( *end == INI_COMMENT_CHAR )
                    *end = '\0';
                rstrip( value );
 
                /* Valid name[=:]value pair found, call handler */
                strncpy0( prev_name, name, sizeof( prev_name ) );
                if( !handler( user, section, name, value ) && !error )
                    error = lineno;
            }
            else if( !error )
            {
                /* No '=' or ':' found on name[=:]value line */
                error = lineno;
            }
        }
 
#if INI_STOP_ON_FIRST_ERROR
        if( error )
            break;
#endif
    }
 
#if !INI_USE_STACK
    free( line );
#endif
 
    return error;
}
 
int ini_parse( const char *filename, int ( *handler )( void *, const char *, const char *, const char * ), void *user )
{
    FILE *file;
    int error;
 
    file = fopen( filename, "r" );
    if( !file )
        return -1;
    error = ini_parse_file( file, handler, user );
    fclose( file );
    return error;
}