utils/ini/ini.cpp

/*
 * Copyright (C) 2017 Amlogic Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define _CRT_SECURE_NO_WARNINGS
//#pragma warning (disable: 4127)

#include <stdio.h>
#include <ctype.h>
#include <string.h>

#include "ini.h"

#if !INI_USE_STACK
#include <stdlib.h>
#endif

#define MAX_SECTION 50
#define MAX_NAME 50

/* 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 == ';')) {
        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;
}

/* See documentation in header file. */
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 == ';' || *start == '#') {
            /* Per Python ConfigParser, allow '#' comments at start of line */
        }
        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;
            }
        }
#if INI_ALLOW_MULTILINE
        else if (*prev_name && *start && (start > line || strstr(start, "=") == NULL)) {
            /* 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 && *start != ';') {
            /* 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 == ';')
                    *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_USE_STACK
    free(line);
#endif

    return error;
}

int ini_parse_mem(const char* buf,
        int (*handler)(void* user, const char* section, const char* name,
                const char* value), void* user) {
    char* bufptr = (char*) buf;

    /* 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

    while (1) {
        int ncount = 0;
        while (*bufptr != '\0') {
            if (*bufptr == '\r' || *bufptr == '\n')
                break;

            line[ncount] = *bufptr++;
            ncount++;
        }
        while (*bufptr == '\r' || *bufptr == '\n')
            bufptr++;
        line[ncount] = 0;

        if (ncount == 0)
            break;

        /* 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 == ';' || *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 != ';') {
            /* 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 == ';')
                    *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_USE_STACK
    free(line);
#endif

    return error;
}

/* See documentation in header file. */
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;
}