/* Add/remove option to the option file section. SYNOPSYS modify_defaults_file() file_location The location of configuration file to edit option option to look for option value The value of the option we would like to set section_name the name of the section remove_option This is true if we want to remove the option. False otherwise. IMPLEMENTATION We open the option file first, then read the file line-by-line, looking for the section we need. At the same time we put these lines into a buffer. Then we look for the option within this section and change/remove it. In the end we get a buffer with modified version of the file. Then we write it to the file, truncate it if needed and close it. RETURN 0 - ok 1 - some error has occured. Probably due to the lack of resourses 2 - cannot open the file */ #include "my_global.h" #include "mysys_priv.h" #include "m_string.h" #include <my_dir.h> #define BUFF_SIZE 1024 #ifdef __WIN__ #define NEWLINE "\r\n" #define NEWLINE_LEN 2 #else #define NEWLINE "\n" #define NEWLINE_LEN 1 #endif int modify_defaults_file(const char *file_location, const char *option, const char *option_value, const char *section_name, int remove_option) { FILE *cnf_file; MY_STAT file_stat; char linebuff[BUFF_SIZE], tmp[BUFF_SIZE], *tmp_ptr, *src_ptr, *dst_ptr, *file_buffer; uint optlen, optval_len, sect_len; my_bool in_section= FALSE; DBUG_ENTER("modify_defaults_file"); optlen= strlen(option); optval_len= strlen(option_value); sect_len= strlen(section_name); if (!(cnf_file= my_fopen(file_location, O_RDWR | O_BINARY, MYF(0)))) DBUG_RETURN(2); /* my_fstat doesn't use the flag parameter */ if (my_fstat(fileno(cnf_file), &file_stat, MYF(0))) goto err; /* Reserve space to read the contents of the file and some more for the option we want to add. */ if (!(file_buffer= (char*) my_malloc(sizeof(char)* (file_stat.st_size + /* option name len */ optlen + /* reserve space for newline */ NEWLINE_LEN + /* reserve for '=' char */ 1 + /* option value len */ optval_len), MYF(MY_WME)))) goto malloc_err; for (dst_ptr= file_buffer, tmp_ptr= 0; fgets(linebuff, BUFF_SIZE, cnf_file); ) { /* Skip over whitespaces */ for (src_ptr= linebuff; my_isspace(&my_charset_latin1, *src_ptr); src_ptr++) {} if (in_section && !strncmp(src_ptr, option, optlen) && (*(src_ptr + optlen) == '=' || my_isspace(&my_charset_latin1, *(src_ptr + optlen)) || *(src_ptr + optlen) == '\0')) { /* The option under modifying was found in this section. Apply new. */ if (!remove_option) dst_ptr= strmov(dst_ptr, tmp); tmp_ptr= 0; /* To mark that we have already applied this */ } else { /* If going to new group and we have option to apply, do it now */ if (tmp_ptr && *src_ptr == '[') { dst_ptr= strmov(dst_ptr, tmp); tmp_ptr= 0; } dst_ptr= strmov(dst_ptr, linebuff); } /* Look for a section */ if (*src_ptr == '[') { /* Copy the line to the buffer */ if (!strncmp(++src_ptr, section_name, sect_len)) { src_ptr+= sect_len; /* Skip over whitespaces. They are allowed after section name */ for (; my_isspace(&my_charset_latin1, *src_ptr); src_ptr++) {} if (*src_ptr != ']') continue; /* Missing closing parenthesis. Assume this was no group */ in_section= TRUE; /* add option */ if (!remove_option) { tmp_ptr= strmov(tmp, option); if (*option_value) { *tmp_ptr++= '='; tmp_ptr= strmov(tmp_ptr, option_value); } /* add a newline */ strmov(tmp_ptr, NEWLINE); } } else in_section= FALSE; /* mark that this section is of no interest to us */ } } /* File ended. New option still remains to apply at the end */ if (tmp_ptr) { if (*(dst_ptr - 1) != '\n') *dst_ptr++= '\n'; dst_ptr= strmov(dst_ptr, tmp); } if (my_chsize(fileno(cnf_file), (my_off_t) (dst_ptr - file_buffer), 0, MYF(MY_WME)) || my_fseek(cnf_file, 0, MY_SEEK_SET, MYF(0)) || my_fwrite(cnf_file, file_buffer, (uint) (dst_ptr - file_buffer), MYF(MY_NABP)) || my_fclose(cnf_file, MYF(MY_WME))) goto err; my_free(file_buffer, MYF(0)); DBUG_RETURN(0); err: my_free(file_buffer, MYF(0)); malloc_err: my_fclose(cnf_file, MYF(0)); DBUG_RETURN(1); /* out of resources */ }