source: MondoRescue/branches/stable/mondo/src/lib/mr_conf.c@ 1571

/* mr_conf.c
 *
 * $Id$
 *
 * Based on the work done by Anton (c)2002-2004 Anton Kulchitsky  mailto:anton@kulchitsky.org
 * Code (c)2006 Bruno Cornec <bruno@mondorescue.org>
 *   
 *     Main file of mr_conf : a very small and simple
 *     library for configuration file reading
 * 
 * Provided under the GPLv2
 */


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

#include "mr_types.h"
#include "mr_msg.h"
#include "mr_mem.h"
#include "mr_gettext.h"

/* error flags */
#define MRCONF_NO_ERROR             0x0
#define MRCONF_BAD_FILE             0x1
#define MRCONF_READING_FAILED       0x3
#define MRCONF_NO_GROUP_START       0x4
#define MRCONF_NO_GROUP_END         0x5
#define MRCONF_FIELD_NOT_FOUND      0x6
#define MRCONF_FIELD_NO_VALUE       0x7
#define MRCONF_TOO_LONG_STRING      0x8
#define MRCONF_CLOSE_BUT_NOT_OPEN   0x9
#define MRCONF_OPEN_OPENED          0xA
#define MRCONF_CALL_BUT_NOT_OPEN    0xB
#define MRCONF_STRING_QUOTE         0xC
#define MRCONF_STRING_ENDQUOTE      0xD

/*setting flags*/
#define MRCONF_FLAG_VERBOSE         0x1

/*All strings of the library are here*/
#define MRCONF_STR_ERROR          _("MRCONF: Error:")
#define MRCONF_STR_WARNING        _("MRCONF: Warning:")

#define MRCONF_STR_BAD_FILE       _("cannot open the file: ")
#define MRCONF_STR_ALLOC_FAILED   _("cannot allocate the memory")
#define MRCONF_STR_READING_FAILED _("cannot read file into buffer")
#define MRCONF_STR_DEFAULT_ERROR  _("default")
#define MRCONF_STR_FIELD_NOT_FOUND   _("the field is not found, field:")
#define MRCONF_STR_FIELD_NO_VALUE   _("the field :")
#define MRCONF_STR_OPEN_OPENED _("attempt to open mr_conf, but it is opened: aborted")
#define MRCONF_STR_HALT _("MRCONF: Error occured: immidiate halt")

/*warnings*/
#define MRCONF_STR_SET_TO_ZERO    _("variable will be set to 0:")
#define MRCONF_STR_IGNORE    _("has no value, ignoring it")
#define MRCONF_STR_CLOSE_BUT_NOT_OPEN _("attempt to close mr_conf but it has not been opened yet")
#define MRCONF_STR_CALL_BUT_NOT_OPEN _("attempt to use mr_conf when it has not been opened yet")
#define MRCONF_STR_STRING_QUOTE     _("string should be surrounded by quotes")
#define MRCONF_STR_STRING_ENDQUOTE      _("a string is not finished by a quote")

/*Flags of internal state*/
#define MRCONF_INTFLAG_OPEN 0x1 /*set if memory allocated */

/* Character for comments */
#define MRCONF_COMM_CHAR '#'

/*"private" members declarations*/
static size_t mr_conf_filesize(const char *name);
#define mr_conf_error_msg(x, y) {mr_conf_error_msg_int(x, y, __LINE__,__FILE__);}
static void mr_conf_error_msg_int(int error_code, const char *add_line, int line, const char *file);
static void mr_conf_remove_comments(void);
static int mr_conf_check_int_flag(const int flag);
static void mr_conf_set_int_flag(const int flag);
static void mr_conf_drop_int_flag(const int flag);

/*global "private" variables*/
static char *buffer = NULL;     /*buffer for configuration file */
static int internal_flags = 0;  /*state of the module */
static FILE *CONF = NULL;       /* Configuration file FD */
static char *mr_conf_filename = NULL;   /* Configuration filename */

/*if output all error and warning messages*/
static int mr_conf_flags = MRCONF_FLAG_VERBOSE;

/* 
 * Format of the configuration file is as follows:
 *
 * attribute1 = int_value
 * attribute2 = float_value
 * attribute3 = string_value
 */


/*open and read file: each call must be coupled with mr_conf_close
  function: return 0 if success*/
int mr_conf_open(const char *filename) {
    size_t length;              /*length of the buffer/file */
    size_t res = 0;

    /* check if mr_conf is already opened? */
    if (mr_conf_check_int_flag(MRCONF_INTFLAG_OPEN)) {
        mr_conf_error_msg(MRCONF_OPEN_OPENED, NULL);
        return MRCONF_OPEN_OPENED;
    }

    length = mr_conf_filesize(filename);
    CONF = fopen(filename, "r");

    mr_asprintf(&mr_conf_filename,filename);

    /*if file is empty or not exist => error */
    if (length == 0) {
        mr_conf_error_msg(MRCONF_BAD_FILE, filename);
        return (MRCONF_BAD_FILE);
    }

    /*creating and reading buffer for file content */

    /*allocate memory for the buffers */
    buffer = (char *) mr_malloc(sizeof(char) * (length + 1));

    /*set flag that module is in "open" state */
    mr_conf_set_int_flag(MRCONF_INTFLAG_OPEN);

    /*reading file in buffer (skip all 0 characters) */

    res = fread(buffer, sizeof(char), length, CONF);
    buffer[length] = (char) 0;  /*finalize the string */

    if (ferror(CONF)) {
        mr_conf_error_msg(MRCONF_READING_FAILED, "");
        return (MRCONF_READING_FAILED);
    }

    /* finally we have to remove all comment lines */
    mr_conf_remove_comments();

    return MRCONF_NO_ERROR;
}

/*release all memory and prepare to the next possiable config file*/
void mr_conf_close(void) {
    /* if not opened => error */
    if (!mr_conf_check_int_flag(MRCONF_INTFLAG_OPEN)) {
        mr_conf_error_msg(MRCONF_CLOSE_BUT_NOT_OPEN, NULL);
    }
    mr_free(buffer);
    fclose(CONF);

    mr_free(mr_conf_filename);

    /*set flag that module is in "close" state */
    mr_conf_drop_int_flag(MRCONF_INTFLAG_OPEN);
}

/*read field value after string str in the current file*/
static char *mr_conf_read(const char *field_name) {
    char *p = NULL;             /*pointer to the field */

    /* check if mr_conf is not yet opened? */
    if (!mr_conf_check_int_flag(MRCONF_INTFLAG_OPEN)) {
        mr_conf_error_msg(MRCONF_CALL_BUT_NOT_OPEN, NULL);
        return NULL;
    }

    /*read the number */
    p = strstr(buffer, field_name);
    if (p == NULL) {
        mr_conf_error_msg(MRCONF_FIELD_NOT_FOUND, field_name);
        return NULL;
    } else {
        p += strlen(field_name);
        while ((*p != '\n') && (*p != '\0') && (*p != '=')) {
                p++;
        }
        if (*p != '=') {
            mr_conf_error_msg(MRCONF_FIELD_NO_VALUE, field_name);
            return NULL;
        } else {
            /* points after the = sign */
            p++;
        }
    }
    /* skip initial spaces and tabs after = */
    while ((*p == ' ') || (*p == '\t')) {
            p++;
    }

    return p;
}

/*read integer number after string str in the current file*/
int mr_conf_iread(const char *field_name) {
    char *p = NULL;             /*pointer to the field */
    int ret = 0;                /*return value */

    p = mr_conf_read(field_name);
    if (p != NULL) {
        ret = atoi(p);
        }
    return ret;
}

/*read float/double number after string str in the current file*/
double mr_conf_fread(const char *field_name) {
    char *p = NULL;             /*pointer to the field */
    double ret = 0.0;               /*return value */

    p = mr_conf_read(field_name);
    if (p != NULL) {
        ret = atof(p);
    }
    return ret;
}


/*
*/
char *mr_conf_sread(const char *field_name) {
    char *p = NULL;             /*pointer to the field */
    char *q = NULL;             /*pointer to the field */
    char *r = NULL;             /*pointer to the field */
    char *ret = NULL;           /*return value */
    int size = 0;               /*size of returned string */
    int i = 0;

    ret = NULL;

    p = mr_conf_read(field_name);
    if (p == NULL) {
        return(p);
    }
    mr_asprintf(&q, p);

    if (*p != '"') {
        mr_conf_error_msg(MRCONF_STRING_QUOTE, field_name);
        return (NULL);
    }
    p++;

    /* trunk at first \n */
    r = index(q,'\n');
    r--;
    if (*r != '"') {
        mr_conf_error_msg(MRCONF_STRING_QUOTE, field_name);
        return (NULL);
    }
    r--;

    size = r-q+1;
    /*copy filtered data to the buffer */
    ret = (char *) mr_malloc(sizeof(char) * (size));
    while (i < size - 1) {
        ret[i] = *p;
        i++;
        p++;
    }

    ret[i] = (char) 0;      /* and set its length */
    mr_free(q);

    return ret;
}

/*read boolean after string str in the current file*/
bool mr_conf_bread(const char *field_name) {
    char *p = NULL;             /*pointer to the field */
    bool ret = FALSE;
    
    p = mr_conf_sread(field_name);
    if (p != NULL) {
        /* match if yes/true/1 */
        if ((strncasecmp(p, "y" , (size_t)1) == 0) ||
            (strncasecmp(p, "t" , (size_t)1) == 0) ||
            (strncasecmp(p, "1" , (size_t)1) == 0)) {
            ret = TRUE;
        }
    }
    return ret;
}

/*removes all comments from the buffer*/
static void mr_conf_remove_comments(void) {
    char *tmp_buf;              /*temporary buffer without comments */
    size_t length               /*initial length */ ;
    size_t i;                   /*iterator */
    size_t k;                   /*conditioned iterator for tmp_buffer */
    bool found_quote = FALSE;
    bool found_comment = FALSE;

    length = strlen(buffer);

    /*sizing the new chain */
    k = 0;
    i = 0;
    while (i < length) {
        /* Handle quotes to detect strings */
        if ((buffer[i] == '"') && (! found_comment)) {
            if (found_quote) {
                found_quote = FALSE;
            } else {
                found_quote = TRUE;
            }
        }
        /* Handle start of comment - only when not in a string */
        if (buffer[i] == MRCONF_COMM_CHAR) {
            if (found_quote) {
                found_comment = FALSE;
            } else {
                found_comment = TRUE;
            }
        }
        /* Comments end with EOL */
        if (buffer[i] == '\n') {
            found_comment = FALSE;
        }
        if (! found_comment) {
            k++;
            i++;
        } else {
            /* Skip comment */
            while ((buffer[i] != '\n') && (buffer[i] != (char) 0)) {
                i++;
            }
            if (buffer[i] == (char) 0) {
                mr_conf_error_msg(MRCONF_STRING_ENDQUOTE, buffer);
            }
        }
    }
    /* k is new buffer length now */
    tmp_buf = (char *) mr_malloc(sizeof(char) * (k + 1));

    k = 0;
    i = 0;
    while (i < length) {
        if (buffer[i] == '"') {
            if (found_quote) {
                found_quote = FALSE;
            } else {
                found_quote = TRUE;
            }
        }
        if ((buffer[i] != MRCONF_COMM_CHAR) || (found_quote)) {
            tmp_buf[k++] = buffer[i++];
        } else {
            /* Skip comment as it's not inside a string */
            while ((buffer[i] != '\n') && (buffer[i] != (char) 0)) {
                i++;
            }
        }
    }
    tmp_buf[k] = (char) 0;      /*and set its length */

    mr_free(buffer);
    /*copy filtered data to the buffer */
    buffer = tmp_buf;
}

static int mr_conf_check_int_flag(const int flag) {
    return (flag & internal_flags);
}

static void mr_conf_set_int_flag(const int flag) {
    internal_flags = flag | internal_flags;
}

static void mr_conf_drop_int_flag(const int flag) {
    internal_flags = (~flag) & internal_flags;
}


/*local function to define size of a file. Return 0 for mistake*/
static size_t mr_conf_filesize(const char *name) {
    FILE *F = fopen(name, "r"); /*file to open */
    size_t length;              /*number to return */

    if (F == NULL) {
        return 0;
    }

    fseek(F, 0, SEEK_END);      /*set position to the end of file */
    length = ftell(F);          /*define number of position=> this is its
                                   length */
    fclose(F);

    return length;
}

/*output error message*/
static void mr_conf_error_msg_int(int error_code, const char *add_line, int line, const char *file) {
    if ((mr_conf_flags & MRCONF_FLAG_VERBOSE)) {    /*if verbose mode */
        switch (error_code) {
        case MRCONF_BAD_FILE:
            mr_msg_int(1,line,file,"%s (%s) %s %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_BAD_FILE,
                   add_line);
            break;

        case MRCONF_READING_FAILED:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_READING_FAILED);
            break;

        case MRCONF_FIELD_NOT_FOUND:
            mr_msg_int(1,line,file,"%s (%s) %s \"%s\"", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_FIELD_NOT_FOUND, add_line);
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_WARNING, mr_conf_filename, MRCONF_STR_SET_TO_ZERO);
            break;

        case MRCONF_FIELD_NO_VALUE:
            mr_msg_int(1,line,file,"%s (%s) %s \"%s\"", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_FIELD_NO_VALUE, add_line);
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_WARNING, mr_conf_filename, MRCONF_STR_IGNORE);
            break;

        case MRCONF_CLOSE_BUT_NOT_OPEN:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_WARNING, mr_conf_filename, MRCONF_STR_CLOSE_BUT_NOT_OPEN);
            break;

        case MRCONF_CALL_BUT_NOT_OPEN:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_WARNING, mr_conf_filename, MRCONF_STR_CALL_BUT_NOT_OPEN);
            break;

        case MRCONF_OPEN_OPENED:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_OPEN_OPENED);
            break;

        case MRCONF_STRING_QUOTE:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_STRING_QUOTE);
            break;

        case MRCONF_STRING_ENDQUOTE:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_STRING_ENDQUOTE);
            break;

        default:
            mr_msg_int(1,line,file,"%s (%s) %s", MRCONF_STR_ERROR, mr_conf_filename, MRCONF_STR_DEFAULT_ERROR);
            break;
        }
    }
}