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- Committer: Brian Aker
- Date: 2009-07-21 00:55:33 UTC
- mfrom: (1093.1.21 captain)
- Revision ID: brian@gaz-20090721005533-ran2v2otw7tbmiym
Merge Jay
- files added:
- drizzled/plugin/handle.h
- files removed:
- mysys/default_modify.cc
- files modified:
- Makefile.am
added
removed
mysys/default_modify.cc
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/* Copyright (C) 2005 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#include "mysys/mysys_priv.h"
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#include <mystrings/m_string.h>
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#include <mysys/my_dir.h>
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#include <stdio.h>
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#include <algorithm>
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using namespace std;
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#define BUFF_SIZE 1024
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#define RESERVE 1024 /* Extend buffer with this extent */
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#define NEWLINE "\n"
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#define NEWLINE_LEN 1
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static char *add_option(char *dst, const char *option_value,
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const char *option, int remove_option);
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/*
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Add/remove option to the option file section.
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SYNOPSYS
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modify_defaults_file()
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file_location The location of configuration file to edit
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option The name of the option to look for (can be NULL)
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option value The value of the option we would like to set (can be NULL)
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section_name The name of the section (must be NOT NULL)
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remove_option This defines what we want to remove:
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- MY_REMOVE_NONE -- nothing to remove;
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- MY_REMOVE_OPTION -- remove the specified option;
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- MY_REMOVE_SECTION -- remove the specified section;
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IMPLEMENTATION
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We open the option file first, then read the file line-by-line,
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looking for the section we need. At the same time we put these lines
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into a buffer. Then we look for the option within this section and
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change/remove it. In the end we get a buffer with modified version of the
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file. Then we write it to the file, truncate it if needed and close it.
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Note that there is a small time gap, when the file is incomplete,
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and this theoretically might introduce a problem.
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RETURN
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0 - ok
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1 - some error has occured. Probably due to the lack of resourses
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2 - cannot open the file
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*/
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int modify_defaults_file(const char *file_location, const char *option,
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const char *option_value,
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const char *section_name, int remove_option)
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{
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FILE *cnf_file;
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struct stat file_stat;
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char linebuff[BUFF_SIZE], *src_ptr, *dst_ptr, *file_buffer;
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size_t opt_len= 0, optval_len= 0, sect_len;
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uint32_t nr_newlines= 0;
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size_t buffer_size;
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bool in_section= false, opt_applied= 0;
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size_t reserve_extended;
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uint32_t new_opt_len;
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int reserve_occupied= 0;
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if (!(cnf_file= fopen(file_location, "r+")))
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return(2);
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if (fstat(fileno(cnf_file), &file_stat))
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goto malloc_err;
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if (option && option_value)
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{
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opt_len= strlen(option);
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optval_len= strlen(option_value);
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}
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new_opt_len= opt_len + 1 + optval_len + NEWLINE_LEN;
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/* calculate the size of the buffer we need */
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reserve_extended= (opt_len +
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1 + /* For '=' char */
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optval_len + /* Option value len */
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NEWLINE_LEN + /* Space for newline */
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RESERVE); /* Some additional space */
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buffer_size= (size_t)max((uint64_t)file_stat.st_size + 1, (uint64_t)SIZE_MAX);
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/*
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Reserve space to read the contents of the file and some more
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for the option we want to add.
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*/
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if (!(file_buffer= (char*) malloc(max(buffer_size + reserve_extended,
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(size_t)SIZE_MAX))))
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goto malloc_err;
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sect_len= strlen(section_name);
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for (dst_ptr= file_buffer; fgets(linebuff, BUFF_SIZE, cnf_file); )
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{
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/* Skip over whitespaces */
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for (src_ptr= linebuff; my_isspace(&my_charset_utf8_general_ci, *src_ptr);
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src_ptr++)
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{}
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if (!*src_ptr) /* Empty line */
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{
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nr_newlines++;
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continue;
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}
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/* correct the option (if requested) */
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if (option && in_section && !strncmp(src_ptr, option, opt_len) &&
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(*(src_ptr + opt_len) == '=' ||
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my_isspace(&my_charset_utf8_general_ci, *(src_ptr + opt_len)) ||
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*(src_ptr + opt_len) == '\0'))
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{
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char *old_src_ptr= src_ptr;
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src_ptr= strchr(src_ptr+ opt_len, '\0'); /* Find the end of the line */
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/* could be negative */
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reserve_occupied+= (int) new_opt_len - (int) (src_ptr - old_src_ptr);
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if (reserve_occupied >= (int) reserve_extended)
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{
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reserve_extended= (uint32_t) reserve_occupied + RESERVE;
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if (!(file_buffer= (char*) realloc(file_buffer, buffer_size +
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reserve_extended)))
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goto malloc_err;
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}
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opt_applied= 1;
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dst_ptr= add_option(dst_ptr, option_value, option, remove_option);
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}
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else
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{
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/*
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If we are going to the new group and have an option to apply, do
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it now. If we are removing a single option or the whole section
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this will only trigger opt_applied flag.
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*/
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if (in_section && !opt_applied && *src_ptr == '[')
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{
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dst_ptr= add_option(dst_ptr, option_value, option, remove_option);
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opt_applied= 1; /* set the flag to do write() later */
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reserve_occupied= new_opt_len+ opt_len + 1 + NEWLINE_LEN;
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}
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for (; nr_newlines; nr_newlines--)
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dst_ptr= strcpy(dst_ptr, NEWLINE)+NEWLINE_LEN;
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/* Skip the section if MY_REMOVE_SECTION was given */
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if (!in_section || remove_option != MY_REMOVE_SECTION)
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dst_ptr= strcpy(dst_ptr, linebuff);
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dst_ptr+= strlen(linebuff);
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}
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/* Look for a section */
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if (*src_ptr == '[')
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{
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/* Copy the line to the buffer */
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if (!strncmp(++src_ptr, section_name, sect_len))
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{
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src_ptr+= sect_len;
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/* Skip over whitespaces. They are allowed after section name */
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for (; my_isspace(&my_charset_utf8_general_ci, *src_ptr); src_ptr++)
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{}
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if (*src_ptr != ']')
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{
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in_section= false;
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continue; /* Missing closing parenthesis. Assume this was no group */
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}
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if (remove_option == MY_REMOVE_SECTION)
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dst_ptr= dst_ptr - strlen(linebuff);
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in_section= true;
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}
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else
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in_section= false; /* mark that this section is of no interest to us */
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}
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}
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/*
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File ended. Apply an option or set opt_applied flag (in case of
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MY_REMOVE_SECTION) so that the changes are saved. Do not do anything
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if we are removing non-existent option.
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*/
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if (!opt_applied && in_section && (remove_option != MY_REMOVE_OPTION))
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{
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/* New option still remains to apply at the end */
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if (!remove_option && *(dst_ptr - 1) != '\n')
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dst_ptr= strcpy(dst_ptr, NEWLINE)+NEWLINE_LEN;
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dst_ptr= add_option(dst_ptr, option_value, option, remove_option);
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opt_applied= 1;
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}
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for (; nr_newlines; nr_newlines--)
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dst_ptr= strcpy(dst_ptr, NEWLINE)+NEWLINE_LEN;
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if (opt_applied)
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{
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/* Don't write the file if there are no changes to be made */
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if (ftruncate(fileno(cnf_file), (size_t) (dst_ptr - file_buffer)) ||
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fseeko(cnf_file, 0, SEEK_SET) ||
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fwrite(file_buffer, 1, (size_t) (dst_ptr - file_buffer), cnf_file))
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goto err;
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}
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if (fclose(cnf_file))
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return(1);
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free(file_buffer);
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return(0);
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err:
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free(file_buffer);
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malloc_err:
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fclose(cnf_file);
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return 1; /* out of resources */
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}
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static char *add_option(char *dst, const char *option_value,
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const char *option, int remove_option)
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{
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if (!remove_option)
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{
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dst= strcpy(dst, option);
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dst+= strlen(option);
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if (*option_value)
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{
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*dst++= '=';
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dst= strcpy(dst, option_value);
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dst+= strlen(option_value);
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}
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/* add a newline */
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dst= strcpy(dst, NEWLINE)+NEWLINE_LEN;
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}
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return dst;
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}
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